Develop Reference

Java tile map using Libgdx: finding tile at mouse position

I've looked at several examples of people creating tile maps, and I am unable to get the tile position where my mouse is pointed at.
I am using a spritebatch and GameTile[][] to create the map. Keep in mind that the tiles themselves are isometric and not actually a square.
The method renderMap() is where the map is actually is being rendered. createMap() just sets the initial GameTiles for an empty map.
The map is able to be dragged and zoomed in and out using Ortho camera.
Zooming out gives me an issue as well, the tiles seem to be shifted over on click
public class MapEditor implements GameScene {
private GameContext context;
private SpriteBatch batch;
private OrthographicCamera camera;
public static GameTile[][] tiles; //GameTile.WIDTH = 64 & GameTile.HEIGHT =48
public static final int MAP_WIDTH = 20;
public static final int MAP_HEIGHT = 36;
public MapEditor(GameContext context) {
this.context = context;
tiles = new GameTile[MAP_WIDTH][MAP_HEIGHT];
}
#Override
public void create() {
renderer = new ShapeRenderer();
this.batch = new SpriteBatch();
camera = new OrthographicCamera(Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
}
public void createMap() {
// Create the sea tiles
for (int x = 0; x < MAP_WIDTH; x++) {
for (int y = 0; y < MAP_HEIGHT; y++) {
if (y < 3 || y > 32) {
if(tiles[x][y] == null) {
tiles[x][y] = safezone;
}
}
else {
if(tiles[x][y] == null) {
tiles[x][y] = cell;
}
}
}
}
}
#Override
public void update(){
// update the camera
camera.update();
}
#Override
public void render() {
batch.setProjectionMatrix(camera.combined);
batch.begin();
Gdx.gl.glViewport(0,0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
renderMap();
batch.end();
}
public int getTileX(float x, float y) {
/*
* getRegionWidth() = TILE_WIDTH_HALF
* getRegionHeight() = TILE_HEIGHT_HALF
* these are the ones being added to worldCoords.x/y
*/
Vector3 worldCoords = camera.unproject(new Vector3(x, y, 0));
return (int)((TILE_WIDTH_HALF * ((-TILE_HEIGHT_HALF + (worldCoords.y + TILE_HEIGHT_HALF)) /
TILE_HEIGHT_HALF) + (worldCoords.x + TILE_WIDTH_HALF)) / TILE_WIDTH_HALF) / 2;
}
public int getTileY(float x, float y) {
/*
* getRegionWidth() = TILE_WIDTH_HALF
* getRegionHeight() = TILE_HEIGHT_HALF
* these are the ones being added to worldCoords.x/y
*/
Vector3 worldCoords = camera.unproject(new Vector3(x, y, 0));
return (int)(((-TILE_HEIGHT_HALF * (TILE_WIDTH_HALF + (worldCoords.x + TILE_WIDTH_HALF)) /
TILE_WIDTH_HALF) + (worldCoords.y + TILE_HEIGHT_HALF)) / TILE_HEIGHT_HALF) / 2;
}
#Override
public boolean handleClick(float x, float y, int button) {
int tileX = getTileX(x,y);
int tileY = getTileY(x,y);
System.out.println("Tile:"+tileX + ","+tileY);
}
private void renderMap() {
for (int i = 0; i < tiles.length; i++) {
for(int j = 0; j < tiles[i].length; j++) {
TextureRegion region = tiles[i][j].getRegion();
int x = (i * GameTile.TILE_WIDTH / 2) - (j * GameTile.TILE_WIDTH / 2) - region.getRegionWidth() / 2;
int y = (i * GameTile.TILE_HEIGHT / 2) + (j * GameTile.TILE_HEIGHT / 2) - region.getRegionHeight() / 2;
if (canDraw(x, y, GameTile.TILE_WIDTH, GameTile.TILE_HEIGHT)) {
batch.draw(region, x, y);
}
}
}
}
Actual tile before doing anything to it;
Actual:
Desired:

Converting Cartesian coordinates to isometric is (sort of) done like this:
float isometricX = cartesianX - cartesianY;
float isometricY = (cartesianX + cartesianY) * 0.5f;
The formula needs to be scaled by the height-to-width ratio of the tiles as well and I think that is where it's going wrong in your code.
Given an unprojected worldMousePosition you can get the coordinates and tile coordinates like this:
float r = (float) TILE_HEIGHT / (float) TILE_WIDTH;
float mapx = (worldMousePosition.x / TILE_HEIGHT + worldMousePosition.y / (TILE_HEIGHT * r)) * r;
float mapy = (worldMousePosition.y / (TILE_HEIGHT * r) - (worldMousePosition.x / TILE_HEIGHT)) * r;
worldPosition = new Vector2(mapx - 0.5f, mapy + 0.5f); // -.5/+.5 because the drawing isn't aligned to the tile, it's aligned to the image
int tileX = (int) worldPosition.x;
int tileY = (int) worldPosition.y;
Full source code for the example above:
import com.badlogic.gdx.Game;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.math.Vector3;
public class SandboxGame extends Game {
public static final int TILE_NONE = -1;
public static final int MAP_WIDTH = 20;
public static final int MAP_HEIGHT = 36;
public static final int TILE_WIDTH = 64;
public static final int TILE_HEIGHT = 48;
private SpriteBatch batch;
private OrthographicCamera camera;
private BitmapFont font;
private Vector3 unprojectVector = new Vector3();
private Vector2 worldMousePosition = new Vector2();
private Vector2 worldPosition = new Vector2();
private Texture[] textures;
private int[][] tiles = new int[MAP_WIDTH][MAP_HEIGHT];
#Override
public void create() {
batch = new SpriteBatch();
camera = new OrthographicCamera(Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
font = new BitmapFont(Gdx.files.internal("default.fnt"), Gdx.files.internal("default.png"), false);
textures = new Texture[] {
new Texture(Gdx.files.internal("tile.png"))
};
for(int x = 0; x < MAP_WIDTH; ++x) {
for(int y = 0; y < MAP_HEIGHT; ++y) {
int rnd = MathUtils.random(10);
if (rnd < 1)
tiles[x][y] = TILE_NONE;
else
tiles[x][y] = 0;
}
}
}
#Override
public void render() {
Gdx.gl.glClearColor(0, 0, 0, 0);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
float scrollSpeed = 64;
float zoomSpeed = 2;
float delta = Gdx.graphics.getDeltaTime();
if (Gdx.input.isKeyPressed(Input.Keys.A))
camera.position.x -= delta * scrollSpeed;
if (Gdx.input.isKeyPressed(Input.Keys.D))
camera.position.x += delta * scrollSpeed;
if (Gdx.input.isKeyPressed(Input.Keys.W))
camera.position.y += delta * scrollSpeed;
if (Gdx.input.isKeyPressed(Input.Keys.S))
camera.position.y -= delta * scrollSpeed;
if (Gdx.input.isKeyPressed(Input.Keys.Q))
camera.zoom = Math.min(camera.zoom + zoomSpeed * delta, 8.0f);
if (Gdx.input.isKeyPressed(Input.Keys.E))
camera.zoom = Math.max(camera.zoom - zoomSpeed * delta, 0.5f);
camera.update();
int mx = Gdx.input.getX();
int my = Gdx.input.getY();
camera.unproject(unprojectVector.set(mx, my, 0.0f));
worldMousePosition.set(unprojectVector.x, unprojectVector.y);
float r = (float) TILE_HEIGHT / (float) TILE_WIDTH;
float mapx = (worldMousePosition.x / TILE_HEIGHT + worldMousePosition.y / (TILE_HEIGHT * r)) * r;
float mapy = (worldMousePosition.y / (TILE_HEIGHT * r) - (worldMousePosition.x / TILE_HEIGHT)) * r;
worldPosition = new Vector2(mapx - 0.5f, mapy + 0.5f); // -.5/+.5 because the drawing isn't aligned to the tile, it's aligned to the image
int tileX = (int) worldPosition.x;
int tileY = (int) worldPosition.y;
batch.setProjectionMatrix(camera.combined);
batch.begin();
for (int col = MAP_WIDTH - 1; col >= 0; --col) {
for (int row = MAP_HEIGHT - 1; row >= 0; --row) {
if (tiles[col][row] != TILE_NONE) {
Texture texture = textures[tiles[col][row]];
int x = (col * TILE_WIDTH / 2) - (row * TILE_WIDTH / 2);
int y = (col * TILE_HEIGHT / 2) + (row * TILE_HEIGHT / 2);
batch.setColor(col == tileX && row == tileY ? Color.GRAY : Color.WHITE);
batch.draw(texture, x, y);
}
}
}
if (Gdx.input.isKeyPressed(Input.Keys.SPACE)) {
for (int col = MAP_WIDTH - 1; col >= 0; --col) {
for (int row = MAP_HEIGHT - 1; row >= 0; --row) {
int x = (col * TILE_WIDTH / 2) - (row * TILE_WIDTH / 2);
int y = (col * TILE_HEIGHT / 2) + (row * TILE_HEIGHT / 2);
font.draw(batch, String.format("(%d, %d)", col, row), x, y);
}
}
}
String str = String.format("World position (%.2f, %.2f), Tile (%d, %d)", worldPosition.x, worldPosition.y, (int)worldPosition.x, (int)worldPosition.y);
font.draw(batch, str, worldMousePosition.x, worldMousePosition.y);
batch.end();
}
}

I cant respond to bornander's post, but my tweak would be at
int tileX = (int) Math.Floor(worldPosition.x);
int tileY = (int) Math.Floor(worldPosition.y);
Where simple (int) cast will provide wrong position around 0 with negative values, if there are tiles, while using Math.Floor will work as intended.

OpenGL Quads Rendering in Black When Rendering Text

So, I'm using LWJGL and OpenGL to render some quads and textures. My quads have been working fine, until the addition of some textures. Specifically, when I added the ability to render text to the screen, all of the quads color has changed to black. I've looked around for a solution but have had no luck, the most common answers are to use glEnable(GL_TEXTURE_2D); only when I draw textures, otherwise keep it disabled when drawing quads. This doesn't seem to be working for me, my quads are still black. I've included my Renderer, Font, and Texture classes below as I'm fairly certain the issue is somewhere in there.
Edit: So I've done a bit more testing, I wasn't even trying to draw normal textures (from .png files) however, now that I've tried to do that as well, I've found they also are drawn completely black. So as of now, the only thing rendering correctly is my font/text, even though I create a texture to render them as well
Renderer.java
public class Renderer {
private VertexArrayObject vao;
private VertexBufferObject vbo;
private ShaderProgram shaderProgram;
private FloatBuffer vertices;
private int numVertices;
private boolean drawing;
private Font fontSketchalot;
public void drawQuad(float x, float y, float width, float height, Colors c) {
glDisable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
begin();
if (vertices.remaining() < 5 * 7) flush();
// Calculate Vertex positions
float x1 = x;
float y1 = y;
float x2 = x + width;
float y2 = y - height;
// Calculate color
float r = c.getR();
float g = c.getG();
float b = c.getB();
// Put data into buffer
vertices.put(x1).put(y1).put(r).put(g).put(b).put(0f).put(1f);
vertices.put(x1).put(y2).put(r).put(g).put(b).put(0f).put(0f);
vertices.put(x2).put(y2).put(r).put(g).put(b).put(1f).put(0f);
vertices.put(x2).put(y1).put(r).put(g).put(b).put(1f).put(1f);
// We drew X vertices
numVertices += 4;
end();
}
public void drawTextureFromTexture(Texture texture, float x, float y, float width, float height) {
drawTexture(texture, x, y, x + width, y - height, 0, 0, 1, 1, Colors.white);
}
public void drawTextureFromFont(Texture texture, float x, float y, float width, float height, float s1, float t1, float sWidth, float sHeight, Colors c) {
drawTexture(texture, x, y, x + width, y - height, s1, t1, s1 + sWidth, t1 + sHeight, c);
}
public void drawTexture(Texture texture, float x1, float y1, float x2, float y2, float s1, float t1, float s2, float t2, Colors c) {
glEnable(GL_TEXTURE_2D);
texture.prepare();
begin();
if (vertices.remaining() < 5 * 7) flush();
// Calculate color
float r = c.getR();
float g = c.getG();
float b = c.getB();
// Put data into buffer
vertices.put(x1).put(y1).put(r).put(g).put(b).put(s1).put(t2);
vertices.put(x1).put(y2).put(r).put(g).put(b).put(s1).put(t1);
vertices.put(x2).put(y2).put(r).put(g).put(b).put(s2).put(t1);
vertices.put(x2).put(y1).put(r).put(g).put(b).put(s2).put(t2);
// We drew X vertices
numVertices += 4;
end();
texture.unbind();
}
public void drawText(String text, float x, float y, float scale, Colors c) {
fontSketchalot.drawText(this, text, x, y, scale, c);
}
// Initialize renderer
public void init(){
// Create font
fontSketchalot = new Font(Fonts.SKETCHALOT);
// Set up shader programs
setupShaderProgram();
// Set wrapping and filtering values
setParameter(GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
setParameter(GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
setParameter(GL_TEXTURE_MIN_FILTER, GL_NEAREST);
setParameter(GL_TEXTURE_MAG_FILTER, GL_NEAREST);
// Enable blending (?????)
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}
// Set parameter of texture
private void setParameter(int name, int value) {
glTexParameteri(GL_TEXTURE_2D, name, value);
}
// Clears drawing area
public void clear() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
// Begin rendering
public void begin() {
if (drawing) throw new IllegalStateException("Renderer is already drawing.");
drawing = true;
numVertices = 0;
}
// End rendering
public void end() {
if (!drawing) throw new IllegalStateException("Renderer is not drawing.");
drawing = false;
flush();
}
// Flushes data to GPU to get rendered
public void flush() {
if (numVertices > 0) {
vertices.flip();
if (vao != null) vao.bind();
else vbo.bind(GL_ARRAY_BUFFER);
specifyVertexAttributes();
}
shaderProgram.use();
// Upload the new vertex data
vbo.bind(GL_ARRAY_BUFFER);
vbo.uploadSubData(GL_ARRAY_BUFFER, 0, vertices);
// Draw batch
glDrawArrays(GL_QUADS, 0, numVertices);
// Clear vertex data for next batch
vertices.clear();
numVertices = 0;
}
private void setupShaderProgram() {
// Generate VertexArrayObject
if (Game.is32Supported()) {
vao = new VertexArrayObject();
vao.bind();
} else {
throw new RuntimeException("OpenGL 3.2 not supported.");
}
// Generate VertexBufferObject
vbo = new VertexBufferObject();
vbo.bind(GL_ARRAY_BUFFER);
// Create FloatBuffer
vertices = MemoryUtil.memAllocFloat(4096);
// Upload null data to allocate storage for the VBO
long size = vertices.capacity() * Float.BYTES;
vbo.uploadData(GL_ARRAY_BUFFER, size, GL_DYNAMIC_DRAW);
// Initialize variables
numVertices = 0;
drawing = false;
// Load Shaders:
Shader vertexShader, fragmentShader;
if (Game.is32Supported()) {
vertexShader = Shader.loadShader(GL_VERTEX_SHADER, "res/shaders/default.vert");
fragmentShader = Shader.loadShader(GL_FRAGMENT_SHADER, "res/shaders/default.frag");
} else {
throw new RuntimeException("OpenGL 3.2 not supported.");
}
// Create ShaderProgram
shaderProgram = new ShaderProgram();
shaderProgram.attachShader(vertexShader);
shaderProgram.attachShader(fragmentShader);
if (Game.is32Supported()) {
shaderProgram.bindFragmentDataLocation(0, "fragColor");
}
shaderProgram.link();
shaderProgram.use();
// Delete linked shaders
vertexShader.delete();
fragmentShader.delete();
// Get width & height of framebuffer
long window = GLFW.glfwGetCurrentContext();
int width, height;
try (MemoryStack stack = MemoryStack.stackPush()) {
IntBuffer widthBuffer = stack.mallocInt(1);
IntBuffer heightBuffer = stack.mallocInt(1);
GLFW.glfwGetFramebufferSize(window, widthBuffer, heightBuffer);
width = widthBuffer.get();
height = heightBuffer.get();
}
// Specify vertex pointers
specifyVertexAttributes();
// Set Model Matrix to identity matrix
Matrix4f model = new Matrix4f();
int uniModel = shaderProgram.getUniformLocation("model");
shaderProgram.setUniform(uniModel, model);
// Set View Matrix to identity matrix
Matrix4f view = new Matrix4f();
int uniView = shaderProgram.getUniformLocation("view");
shaderProgram.setUniform(uniView, view);
// Set Projection Matrix to an orthographic projection
Matrix4f projection = Matrix4f.orthographic(0f, width, 0f, height, -1f, 1f);
int uniProjection = shaderProgram.getUniformLocation("projection");
shaderProgram.setUniform(uniProjection, projection);
}
// Specifies the vertex shader pointers (attributes)
private void specifyVertexAttributes() {
int posAttrib = shaderProgram.getAttributeLocation("position");
shaderProgram.enableVertexAttribute(posAttrib);
shaderProgram.pointVertexAttribute(posAttrib, 2, 7 * Float.BYTES, 0);
int colAttrib = shaderProgram.getAttributeLocation("color");
shaderProgram.enableVertexAttribute(colAttrib);
shaderProgram.pointVertexAttribute(colAttrib, 3, 7 * Float.BYTES, 2 * Float.BYTES);
int texAttrib = shaderProgram.getAttributeLocation("texcoord");
shaderProgram.enableVertexAttribute(texAttrib);
shaderProgram.pointVertexAttribute(texAttrib, 2, 7 * Float.BYTES, 5 * Float.BYTES);
int uniTex = shaderProgram.getUniformLocation("texImage");
shaderProgram.setUniform(uniTex, 0);
}
}
Font.java
public class Font {
private String fontPath;
private java.awt.Font font;
private Map<Character, Glyph> glyphs;
private float fontHeight;
private Texture texture;
public Font(String fontPath) {
System.out.println("Creating font...");
this.fontPath = fontPath;
loadFont();
glyphs = new HashMap<>();
texture = createFontTexture();
System.out.println("Font created.");
}
public Font() {
System.out.println("Creating font...");
this.fontPath = "DEFAULT";
font = new java.awt.Font(java.awt.Font.MONOSPACED, java.awt.Font.PLAIN, 30);
glyphs = new HashMap<>();
texture = createFontTexture();
System.out.println("Font created.");
}
private void loadFont() {
try {
System.out.println("Loading font...");
font = java.awt.Font.createFont(java.awt.Font.TRUETYPE_FONT, new FileInputStream(fontPath)).deriveFont(java.awt.Font.PLAIN, 30);
System.out.println("Font loaded.");
} catch (Exception e) {
throw new RuntimeException("Could not load font.");
}
}
private Texture createFontTexture() {
int imageWidth = 0;
int imageHeight = 0;
// Add up total width and height
for (int i = 32; i < 256; i++) {
if (i == 127) { // DEL control code
continue;
}
char c = (char) i;
BufferedImage ch = createCharImage(c);
if (ch == null) {
System.out.println("Could not load [CHAR: \"" + c + "\"] from font: " + fontPath);
continue;
}
imageWidth += ch.getWidth();
imageHeight = Math.max(imageHeight, ch.getHeight());
}
fontHeight = Converter.glfwCoordToOpenGLCoord(imageHeight);
/* Image for the texture */
BufferedImage image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
// Set up glyphs (Map<CHAR, GLYPH>)
int xOffsetI = 0;
float xOffsetF = 0;
for (int i = 32; i < 256; i++) {
if (i == 127) { // DEL control code
continue;
}
char c = (char) i;
BufferedImage charImage = createCharImage(c);
if (charImage == null) {
System.out.println("Could not load [CHAR: \"" + c + "\"] from font: " + fontPath);
continue;
}
int charWidth = charImage.getWidth();
int charHeight = charImage.getHeight();
// Create glyph
Glyph ch = new Glyph(Converter.glfwCoordToOpenGLCoord(charWidth), Converter.glfwCoordToOpenGLCoord(charHeight), ((float)charWidth / (float)imageWidth), (float)charHeight / (float)imageHeight, xOffsetF, 0.0f);
// Draw char on image
g.drawImage(charImage, xOffsetI, 0, null);
xOffsetI += charWidth;
xOffsetF += ch.sWidth;
// Put in map
glyphs.put(c, ch);
}
// Flip image Horizontal to get the origin to bottom left
AffineTransform transform = AffineTransform.getScaleInstance(1f, -1f);
transform.translate(0, -image.getHeight());
AffineTransformOp operation = new AffineTransformOp(transform, AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
image = operation.filter(image, null);
// Get char width & char height of image
int width = image.getWidth();
int height = image.getHeight();
// Put pixel data into int[] pixels
int[] pixels = new int[width * height];
image.getRGB(0, 0, width, height, pixels, 0, width);
// Put pixel data into byte buffer
ByteBuffer buffer = MemoryUtil.memAlloc(width * height * 4);
for (int i = 0; i < height; i++){
for (int j = 0; j < width; j++) {
// Pixel format : OxAARRGGBB
int pixel = pixels[i * width + j];
buffer.put((byte) ((pixel >> 16) & 0xFF)); // 0x000000RR
buffer.put((byte) ((pixel >> 8) & 0xFF)); // 0x000000GG
buffer.put((byte) ((pixel) & 0xFF)); // 0x000000BB
buffer.put((byte) ((pixel >> 24) & 0xFF)); // 0x000000AA
//buffer.put((byte)(0xFF)); // Test
}
}
buffer.flip(); // Set index back to 0
Texture fontTexture = Texture.createTexture(width, height, buffer); // Create texture
MemoryUtil.memFree(buffer); // Free buffer
return fontTexture;
}
private BufferedImage createCharImage(char c) {
// Begin by calculating proper width and height
BufferedImage image = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
if (Options.ANTIALIAS) {
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
g.setFont(font);
FontMetrics fontMetrics = g.getFontMetrics();
g.dispose();
int charWidth = fontMetrics.charWidth(c);
int charHeight = fontMetrics.getHeight();
if (charWidth == 0) return null;
// Now set up the image
image = new BufferedImage(charWidth, charHeight, BufferedImage.TYPE_INT_ARGB);
g = image.createGraphics();
if (Options.ANTIALIAS) {
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
}
g.setFont(font);
g.setPaint(Color.WHITE); // Use white so we can set the color while rendering
g.drawString(String.valueOf(c), 0, fontMetrics.getAscent()); // Paint char onto image
g.dispose();
// Finally return the final image
return image;
}
public void drawText(Renderer renderer, CharSequence text, float x, float y, float scale, Colors c) {
float xOffset = 0;
float yOffset = 0;
texture.prepare();
//renderer.begin();
for (int i = 0; i < text.length(); i++) {
char ch = text.charAt(i);
if (ch == '\n') {
// If we start a new line, change the yOffset to reflect (then continue)
yOffset -= fontHeight;
continue;
}
if (ch == '\r') {
// Skip carriage return
continue;
}
Glyph g = glyphs.get(ch);
renderer.drawTextureFromFont(texture, x + xOffset, y + yOffset, g.width * scale, g.height * scale, g.s, g.t, g.sWidth, g.sHeight, c);
xOffset += g.width * scale;
}
//renderer.end();
texture.unbind();
}
}
Texture.java
public class Texture {
// Store handle
private final int id;
private int width;
private int height;
private ByteBuffer image;
// Draw texture using given renderer
public void draw(Renderer renderer, float x, float y, float scale) {
// Scale texture
float w = ((float)width * scale * 2) / (Game.WIDTH);
float h = ((float)height * scale * 2) / (Game.HEIGHT);
renderer.drawTextureFromTexture(this, x, y, w, h);
}
// Create new texture
public Texture() {
id = glGenTextures();
}
// Prepare texture to be drawn
public void prepare() {
bind();
uploadData(width, height, image);
}
// Bind texture
public void bind() {
glBindTexture(GL_TEXTURE_2D, id);
}
// Set parameter of texture
private void setParameter(int name, int value) {
glTexParameteri(GL_TEXTURE_2D, name, value);
}
// Upload image data with specified width and height
public void uploadData(int width, int height, ByteBuffer data) {
uploadData(GL_RGBA8, width, height, GL_RGBA, data);
}
// Upload image data with specified internal format, width, height, and image format
public void uploadData(int internalFormat, int width, int height, int format, ByteBuffer data) {
glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, width, height, 0, format, GL_UNSIGNED_BYTE, data);
}
// Delete texture
public void delete() {
glDeleteTextures(id);
}
// Get width
public int getWidth() {
return width;
}
// Set width
public void setWidth(int width) {
if (width > 0) {
this.width = width;
}
}
// Get height
public int getHeight() {
return height;
}
// Set height
public void setHeight(int height) {
if (height > 0) {
this.height = height;
}
}
// Set image
public void setImage(ByteBuffer image) {
this.image = image;
}
public static Texture createTexture(int width, int height, ByteBuffer image) {
Texture texture = new Texture();
texture.setWidth(width);
texture.setHeight(height);
texture.setImage(image);
texture.prepare();
return texture;
}
public static Texture loadTexture(String path) {
ByteBuffer image;
int width, height;
try (MemoryStack stack = MemoryStack.stackPush()) {
IntBuffer w = stack.mallocInt(1);
IntBuffer h = stack.mallocInt(1);
IntBuffer comp = stack.mallocInt(1);
// Load image
stbi_set_flip_vertically_on_load(true);
image = stbi_load(path, w, h, comp, 4);
if (image == null) throw new RuntimeException("Could not load texture.");
width = w.get();
height = h.get();
}
return createTexture(width, height, image);
}
public void unbind() {
glBindTexture(GL_TEXTURE_2D, 0);
}
}

fillArc() in Java not blending color as expected

I'm trying to blend all the colors into a circle using arcs.
However, the arc comes as one solid color and not a blend of color as I thought.
Is it possible to?
public static void main(String[] args) {
DrawingPanel panel = new DrawingPanel(512,512);
Graphics g = panel.getGraphics();
int width = 100;
int height = 100;
g.drawOval(0,0,width, height);
//yellow
for( int i = 0; i < 100 ; i++){
Color c = new Color(255/100*i,255,0);
g.setColor(c);
g.fillArc(0,0,width,height,95,11);
}

g.fillArc(0,0,width,height,95,11);
You need to change the arc angle for every iteration and the arc size should be fixed at a certain value. I'm not sure what the value would be because I would expect you should iterate 360 times (in which case the size would be 1), not 100.
You can use the HSL Color class to do this simply.
An HSL color allows you to change the "hue" of the color in degrees. So you just need a simple loop to set/paint the color in a 1 degree arc:
import java.awt.*;
import java.awt.geom.*;
import java.awt.event.*;
import javax.swing.*;
public class ColorWheel extends JPanel
{
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
HSLColor color = new HSLColor( Color.YELLOW );
for (int i = 0; i < 360; i++)
{
g.setColor( color.adjustHue(i) );
g.fillArc( 25, 25, 200, 200, i, 1);
}
}
#Override
public Dimension getPreferredSize()
{
return new Dimension(250, 250);
}
private static void createAndShowGUI()
{
JComponent wheel = new ColorWheel();
JFrame frame = new JFrame("Color Wheel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setContentPane( wheel );
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
}
I used the HSL Color because it has a simple API to change the hue.
If you don't want to use that class then you can use Color.getHSBColor(...) method to get the color for each degree of change. Again the saturation and brightness would be fixed values and then you just change the hue.
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
float hueDegree = 1 / 360.0f;
for (int i = 0; i < 360; i++)
{
Color color = Color.getHSBColor(i * hueDegree, 1.0f, 1.0f);
g.setColor( color );
g.fillArc( 25, 25, 200, 200, i, 1);
}
}

Along time ago, I stumbled across a ConicalGradientPaint from Harmonic Code (there source is there somewhere, I just can't seem to find it again, but I've included my copy of it in the example).
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ColorWheel {
public static void main(String[] args) {
new ColorWheel();
}
public ColorWheel() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
ConicalGradientPaint rgp = new ConicalGradientPaint(
true,
new Point(getWidth() / 2, getHeight() / 2),
0.5f,
new float[]{0, 60, 120, 180, 240, 300, 360},
new Color[]{Color.RED, Color.YELLOW, Color.GREEN, Color.CYAN, Color.BLUE, Color.MAGENTA, Color.RED});
g2d.setPaint(rgp);
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
g2d.fillOval(x, y, radius, radius);
g2d.dispose();
}
}
public final class ConicalGradientPaint implements java.awt.Paint {
private final java.awt.geom.Point2D CENTER;
private final double[] FRACTION_ANGLES;
private final double[] RED_STEP_LOOKUP;
private final double[] GREEN_STEP_LOOKUP;
private final double[] BLUE_STEP_LOOKUP;
private final double[] ALPHA_STEP_LOOKUP;
private final java.awt.Color[] COLORS;
private static final float INT_TO_FLOAT_CONST = 1f / 255f;
/**
* Standard constructor which takes the FRACTIONS in values from 0.0f to
* 1.0f
*
* #param CENTER
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final java.awt.geom.Point2D CENTER, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
this(false, CENTER, 0.0f, GIVEN_FRACTIONS, GIVEN_COLORS);
}
/**
* Enhanced constructor which takes the FRACTIONS in degress from 0.0f to
* 360.0f and also an GIVEN_OFFSET in degrees around the rotation CENTER
*
* #param USE_DEGREES
* #param CENTER
* #param GIVEN_OFFSET
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final boolean USE_DEGREES, final java.awt.geom.Point2D CENTER, final float GIVEN_OFFSET, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
// Check that fractions and colors are of the same size
if (GIVEN_FRACTIONS.length != GIVEN_COLORS.length) {
throw new IllegalArgumentException("Fractions and colors must be equal in size");
}
final java.util.ArrayList<Float> FRACTION_LIST = new java.util.ArrayList<Float>(GIVEN_FRACTIONS.length);
final float OFFSET;
if (USE_DEGREES) {
final double DEG_FRACTION = 1f / 360f;
if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), -0.5) == 0) {
OFFSET = -0.5f;
} else if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), 0.5) == 0) {
OFFSET = 0.5f;
} else {
OFFSET = (float) (GIVEN_OFFSET * DEG_FRACTION);
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add((float) (fraction * DEG_FRACTION));
}
} else {
// Now it seems to work with rotation of 0.5f, below is the old code to correct the problem
// if (GIVEN_OFFSET == -0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly -0.5
// OFFSET = -0.49999f;
// }
// else if (GIVEN_OFFSET == 0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly +0.5
// OFFSET = 0.499999f;
// }
// else
{
OFFSET = GIVEN_OFFSET;
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add(fraction);
}
}
// Check for valid offset
if (OFFSET > 0.5f || OFFSET < -0.5f) {
throw new IllegalArgumentException("Offset has to be in the range of -0.5 to 0.5");
}
// Adjust fractions and colors array in the case where startvalue != 0.0f and/or endvalue != 1.0f
final java.util.List<java.awt.Color> COLOR_LIST = new java.util.ArrayList<java.awt.Color>(GIVEN_COLORS.length);
COLOR_LIST.addAll(java.util.Arrays.asList(GIVEN_COLORS));
// Assure that fractions start with 0.0f
if (FRACTION_LIST.get(0) != 0.0f) {
FRACTION_LIST.add(0, 0.0f);
final java.awt.Color TMP_COLOR = COLOR_LIST.get(0);
COLOR_LIST.add(0, TMP_COLOR);
}
// Assure that fractions end with 1.0f
if (FRACTION_LIST.get(FRACTION_LIST.size() - 1) != 1.0f) {
FRACTION_LIST.add(1.0f);
COLOR_LIST.add(GIVEN_COLORS[0]);
}
// Recalculate the fractions and colors with the given offset
final java.util.Map<Float, java.awt.Color> FRACTION_COLORS = recalculate(FRACTION_LIST, COLOR_LIST, OFFSET);
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
// Sort the hashmap by fraction and add the values to the FRACION_LIST and COLOR_LIST
final java.util.SortedSet<Float> SORTED_FRACTIONS = new java.util.TreeSet<Float>(FRACTION_COLORS.keySet());
final java.util.Iterator<Float> ITERATOR = SORTED_FRACTIONS.iterator();
while (ITERATOR.hasNext()) {
final float CURRENT_FRACTION = ITERATOR.next();
FRACTION_LIST.add(CURRENT_FRACTION);
COLOR_LIST.add(FRACTION_COLORS.get(CURRENT_FRACTION));
}
// Set the values
this.CENTER = CENTER;
COLORS = COLOR_LIST.toArray(new java.awt.Color[]{});
// Prepare lookup table for the angles of each fraction
final int MAX_FRACTIONS = FRACTION_LIST.size();
this.FRACTION_ANGLES = new double[MAX_FRACTIONS];
for (int i = 0; i < MAX_FRACTIONS; i++) {
FRACTION_ANGLES[i] = FRACTION_LIST.get(i) * 360;
}
// Prepare lookup tables for the color stepsize of each color
RED_STEP_LOOKUP = new double[COLORS.length];
GREEN_STEP_LOOKUP = new double[COLORS.length];
BLUE_STEP_LOOKUP = new double[COLORS.length];
ALPHA_STEP_LOOKUP = new double[COLORS.length];
for (int i = 0; i < (COLORS.length - 1); i++) {
RED_STEP_LOOKUP[i] = ((COLORS[i + 1].getRed() - COLORS[i].getRed()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
GREEN_STEP_LOOKUP[i] = ((COLORS[i + 1].getGreen() - COLORS[i].getGreen()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
BLUE_STEP_LOOKUP[i] = ((COLORS[i + 1].getBlue() - COLORS[i].getBlue()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
ALPHA_STEP_LOOKUP[i] = ((COLORS[i + 1].getAlpha() - COLORS[i].getAlpha()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
}
}
/**
* Recalculates the fractions in the FRACTION_LIST and their associated
* colors in the COLOR_LIST with a given OFFSET. Because the conical
* gradients always starts with 0 at the top and clockwise direction you
* could rotate the defined conical gradient from -180 to 180 degrees which
* equals values from -0.5 to +0.5
*
* #param FRACTION_LIST
* #param COLOR_LIST
* #param OFFSET
* #return Hashmap that contains the recalculated fractions and colors after
* a given rotation
*/
private java.util.HashMap<Float, java.awt.Color> recalculate(final java.util.List<Float> FRACTION_LIST, final java.util.List<java.awt.Color> COLOR_LIST, final float OFFSET) {
// Recalculate the fractions and colors with the given offset
final int MAX_FRACTIONS = FRACTION_LIST.size();
final java.util.HashMap<Float, java.awt.Color> FRACTION_COLORS = new java.util.HashMap<Float, java.awt.Color>(MAX_FRACTIONS);
for (int i = 0; i < MAX_FRACTIONS; i++) {
// Add offset to fraction
final float TMP_FRACTION = FRACTION_LIST.get(i) + OFFSET;
// Color related to current fraction
final java.awt.Color TMP_COLOR = COLOR_LIST.get(i);
// Check each fraction for limits (0...1)
if (TMP_FRACTION <= 0) {
FRACTION_COLORS.put(1.0f + TMP_FRACTION + 0.0001f, TMP_COLOR);
final float NEXT_FRACTION;
final java.awt.Color NEXT_COLOR;
if (i < MAX_FRACTIONS - 1) {
NEXT_FRACTION = FRACTION_LIST.get(i + 1) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(i + 1);
} else {
NEXT_FRACTION = 1 - FRACTION_LIST.get(0) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(0);
}
if (NEXT_FRACTION > 0) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, NEXT_COLOR, (int) ((NEXT_FRACTION - TMP_FRACTION) * 10000), (int) ((-TMP_FRACTION) * 10000));
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
}
} else if (TMP_FRACTION >= 1) {
FRACTION_COLORS.put(TMP_FRACTION - 1.0f - 0.0001f, TMP_COLOR);
final float PREVIOUS_FRACTION;
final java.awt.Color PREVIOUS_COLOR;
if (i > 0) {
PREVIOUS_FRACTION = FRACTION_LIST.get(i - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(i - 1);
} else {
PREVIOUS_FRACTION = FRACTION_LIST.get(MAX_FRACTIONS - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(MAX_FRACTIONS - 1);
}
if (PREVIOUS_FRACTION < 1) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, PREVIOUS_COLOR, (int) ((TMP_FRACTION - PREVIOUS_FRACTION) * 10000), (int) (TMP_FRACTION - 1.0f) * 10000);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
}
} else {
FRACTION_COLORS.put(TMP_FRACTION, TMP_COLOR);
}
}
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
return FRACTION_COLORS;
}
/**
* With the START_COLOR at the beginning and the DESTINATION_COLOR at the
* end of the given RANGE the method will calculate and return the color
* that equals the given VALUE. e.g. a START_COLOR of BLACK (R:0, G:0, B:0,
* A:255) and a DESTINATION_COLOR of WHITE(R:255, G:255, B:255, A:255) with
* a given RANGE of 100 and a given VALUE of 50 will return the color that
* is exactly in the middle of the gradient between black and white which is
* gray(R:128, G:128, B:128, A:255) So this method is really useful to
* calculate colors in gradients between two given colors.
*
* #param START_COLOR
* #param DESTINATION_COLOR
* #param RANGE
* #param VALUE
* #return Color calculated from a range of values by given value
*/
public java.awt.Color getColorFromFraction(final java.awt.Color START_COLOR, final java.awt.Color DESTINATION_COLOR, final int RANGE, final int VALUE) {
final float SOURCE_RED = START_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float SOURCE_GREEN = START_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float SOURCE_BLUE = START_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float SOURCE_ALPHA = START_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float DESTINATION_RED = DESTINATION_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float DESTINATION_GREEN = DESTINATION_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float DESTINATION_BLUE = DESTINATION_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float DESTINATION_ALPHA = DESTINATION_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float RED_DELTA = DESTINATION_RED - SOURCE_RED;
final float GREEN_DELTA = DESTINATION_GREEN - SOURCE_GREEN;
final float BLUE_DELTA = DESTINATION_BLUE - SOURCE_BLUE;
final float ALPHA_DELTA = DESTINATION_ALPHA - SOURCE_ALPHA;
final float RED_FRACTION = RED_DELTA / RANGE;
final float GREEN_FRACTION = GREEN_DELTA / RANGE;
final float BLUE_FRACTION = BLUE_DELTA / RANGE;
final float ALPHA_FRACTION = ALPHA_DELTA / RANGE;
//System.out.println(DISTANCE + " " + CURRENT_FRACTION);
return new java.awt.Color(SOURCE_RED + RED_FRACTION * VALUE, SOURCE_GREEN + GREEN_FRACTION * VALUE, SOURCE_BLUE + BLUE_FRACTION * VALUE, SOURCE_ALPHA + ALPHA_FRACTION * VALUE);
}
#Override
public java.awt.PaintContext createContext(final java.awt.image.ColorModel COLOR_MODEL, final java.awt.Rectangle DEVICE_BOUNDS, final java.awt.geom.Rectangle2D USER_BOUNDS, final java.awt.geom.AffineTransform TRANSFORM, final java.awt.RenderingHints HINTS) {
final java.awt.geom.Point2D TRANSFORMED_CENTER = TRANSFORM.transform(CENTER, null);
return new ConicalGradientPaintContext(TRANSFORMED_CENTER);
}
#Override
public int getTransparency() {
return java.awt.Transparency.TRANSLUCENT;
}
private final class ConicalGradientPaintContext implements java.awt.PaintContext {
final private java.awt.geom.Point2D CENTER;
public ConicalGradientPaintContext(final java.awt.geom.Point2D CENTER) {
this.CENTER = new java.awt.geom.Point2D.Double(CENTER.getX(), CENTER.getY());
}
#Override
public void dispose() {
}
#Override
public java.awt.image.ColorModel getColorModel() {
return java.awt.image.ColorModel.getRGBdefault();
}
#Override
public java.awt.image.Raster getRaster(final int X, final int Y, final int TILE_WIDTH, final int TILE_HEIGHT) {
final double ROTATION_CENTER_X = -X + CENTER.getX();
final double ROTATION_CENTER_Y = -Y + CENTER.getY();
final int MAX = FRACTION_ANGLES.length;
// Create raster for given colormodel
final java.awt.image.WritableRaster RASTER = getColorModel().createCompatibleWritableRaster(TILE_WIDTH, TILE_HEIGHT);
// Create data array with place for red, green, blue and alpha values
int[] data = new int[(TILE_WIDTH * TILE_HEIGHT * 4)];
double dx;
double dy;
double distance;
double angle;
double currentRed = 0;
double currentGreen = 0;
double currentBlue = 0;
double currentAlpha = 0;
for (int py = 0; py < TILE_HEIGHT; py++) {
for (int px = 0; px < TILE_WIDTH; px++) {
// Calculate the distance between the current position and the rotation angle
dx = px - ROTATION_CENTER_X;
dy = py - ROTATION_CENTER_Y;
distance = Math.sqrt(dx * dx + dy * dy);
// Avoid division by zero
if (distance == 0) {
distance = 1;
}
// 0 degree on top
angle = Math.abs(Math.toDegrees(Math.acos(dx / distance)));
if (dx >= 0 && dy <= 0) {
angle = 90.0 - angle;
} else if (dx >= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy <= 0) {
angle = 450.0 - angle;
}
// Check for each angle in fractionAngles array
for (int i = 0; i < (MAX - 1); i++) {
if ((angle >= FRACTION_ANGLES[i])) {
currentRed = COLORS[i].getRed() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * RED_STEP_LOOKUP[i];
currentGreen = COLORS[i].getGreen() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * GREEN_STEP_LOOKUP[i];
currentBlue = COLORS[i].getBlue() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * BLUE_STEP_LOOKUP[i];
currentAlpha = COLORS[i].getAlpha() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * ALPHA_STEP_LOOKUP[i];
continue;
}
}
// Fill data array with calculated color values
final int BASE = (py * TILE_WIDTH + px) * 4;
data[BASE + 0] = (int) (currentRed * 255);
data[BASE + 1] = (int) (currentGreen * 255);
data[BASE + 2] = (int) (currentBlue * 255);
data[BASE + 3] = (int) (currentAlpha * 255);
}
}
// Fill the raster with the data
RASTER.setPixels(0, 0, TILE_WIDTH, TILE_HEIGHT, data);
return RASTER;
}
}
}
}
To try and do what you're doing with a pie slices, you need to slow alter the color from one point to another, using very small slices. So, while you might start with Color.RED and want to blend to Color.YELLOW, you would actually need to generate each color between them (based on the distance)
For example...
import core.ui.ColorUtilities;
import static core.ui.ColorUtilities.blend;
import static core.ui.ColorUtilities.getFractionIndicies;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ColorWheel {
public static void main(String[] args) {
new ColorWheel();
}
public ColorWheel() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
float fractions[] = new float[]{0, 0.16f, 0.33f, 0.5f, 0.66f, 0.83f, 1f};
Color colors[] = new Color[]{Color.RED, Color.YELLOW, Color.GREEN, Color.CYAN, Color.BLUE, Color.MAGENTA, Color.RED};
for (int index = 0; index < getWidth(); index++) {
float progress = (float) index / getWidth();
System.out.println(progress);
Color color = blendColors(fractions, colors, progress);
g2d.setColor(color);
g2d.drawLine(index, 0, index, getHeight());
}
g2d.dispose();
}
}
/**
* This will attempt to blend two colors that site between the supplied
* progress value, based on the distance of the progress value...
*
* For example, if you have a series of fractions of {0f, 0.5f, 1f} and a
* progress of 25%, the resulting color will be a 50% blend of the first and
* second color (as the progress is half between those two points)
*
* #param fractions
* #param colors
* #param progress
* #return
*/
public static Color blendColors(float[] fractions, Color[] colors, float progress) {
Color color = null;
if (fractions != null) {
if (colors != null) {
if (fractions.length == colors.length) {
int[] indicies = getFractionIndicies(fractions, progress);
float[] range = new float[]{fractions[indicies[0]], fractions[indicies[1]]};
Color[] colorRange = new Color[]{colors[indicies[0]], colors[indicies[1]]};
float max = range[1] - range[0];
float value = progress - range[0];
float weight = value / max;
color = blend(colorRange[0], colorRange[1], 1f - weight);
} else {
throw new IllegalArgumentException("Fractions and colours must have equal number of elements");
}
} else {
throw new IllegalArgumentException("Colours can't be null");
}
} else {
throw new IllegalArgumentException("Fractions can't be null");
}
return color;
}
}
I know, it's note a wheel, but i was demonstrating the blending algorithm, I'll leave the pie slicing up to you ;)
Just proving to myself it could work...
int dimeter = Math.min(getWidth(), getHeight());
int x = (getWidth() - dimeter) / 2;
int y = (getHeight() - dimeter) / 2;
for (int angle = 0; angle < 360; angle++) {
float progress = (float) angle / 360;
System.out.println(progress);
Color color = blendColors(fractions, colors, progress);
g2d.setColor(color);
g2d.fillArc(x, y, dimeter, dimeter, angle + 90, 2);
}

Draw an Arc and gradient it

I would like to know if its possible to draw a Arc on a graphics Panel using a gradient and how I would go about it.
My end goal would be to rotate the arc in a full circle so it would be similar to a rotating loading circle. However it is not a loading bar. It would be a background of a custom JButton.
Any suggestions to alternatives that would create a similar effect would be appreciated.
This is similar to what oi want to draw. Keep in mind that it will be "rotating"

public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
public TestPane() {
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
RadialGradientPaint rgp = new RadialGradientPaint(
new Point(getWidth() / 2, getHeight() / 2),
radius,
new float[]{0f, 1f},
new Color[]{Color.RED, Color.YELLOW}
);
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, 0, 45, Arc2D.PIE));
g2d.dispose();
}
}
}
You might like to have a look at 2D Graphics for more info
Updated after additional input
So you want a conical fill effect then...
The implementation I have comes from Harmonic Code, but I can't find a direct reference to it (I think it's part of his (excellent) series), but you can see the source code here
Now. I had issues with the angles as it appears that 0 starts at the top point (not the left) and it doesn't like negative angles...you might have better luck, but what I did was create a basic buffer at a position I could easily get working and then rotate the graphics context using an AffineTransformation...
public class TestArc {
public static void main(String[] args) {
new TestArc();
}
public TestArc() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private float angle = 0;
private float extent = 270;
private BufferedImage buffer;
public TestPane() {
Timer timer = new Timer(125, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
angle -= 5;
if (angle > 360) {
angle = 0;
}
repaint();
}
});
timer.setRepeats(true);
timer.setCoalesce(false);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected BufferedImage getBuffer() {
if (buffer == null) {
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth() - radius) / 2;
int y = (getHeight() - radius) / 2;
buffer = new BufferedImage(radius, radius, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = buffer.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
float startAngle = 0;
Color start = new Color(0, 128, 0, 128);
Color end = new Color(0, 128, 0, 0);
ConicalGradientPaint rgp = new ConicalGradientPaint(
true,
new Point(getWidth() / 2, getHeight() / 2),
0.5f,
new float[]{startAngle, extent},
new Color[]{start, end});
g2d.setPaint(rgp);
g2d.fill(new Arc2D.Float(x, y, radius, radius, startAngle + 90, -extent, Arc2D.PIE));
// g2d.fill(new Ellipse2D.Float(0, 0, radius, radius));
g2d.dispose();
g2d.dispose();
}
return buffer;
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
int radius = Math.min(getWidth(), getHeight());
int x = (getWidth()) / 2;
int y = (getHeight()) / 2;
BufferedImage buffer = getBuffer();
g2d.setTransform(AffineTransform.getRotateInstance(Math.toRadians(angle), x, y));
x = (getWidth() - buffer.getWidth()) / 2;
y = (getHeight() - buffer.getHeight()) / 2;
g2d.drawImage(buffer, x, y, this);
g2d.dispose();
}
}
public final class ConicalGradientPaint implements java.awt.Paint {
private final java.awt.geom.Point2D CENTER;
private final double[] FRACTION_ANGLES;
private final double[] RED_STEP_LOOKUP;
private final double[] GREEN_STEP_LOOKUP;
private final double[] BLUE_STEP_LOOKUP;
private final double[] ALPHA_STEP_LOOKUP;
private final java.awt.Color[] COLORS;
private static final float INT_TO_FLOAT_CONST = 1f / 255f;
/**
* Standard constructor which takes the FRACTIONS in values from 0.0f to
* 1.0f
*
* #param CENTER
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final java.awt.geom.Point2D CENTER, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
this(false, CENTER, 0.0f, GIVEN_FRACTIONS, GIVEN_COLORS);
}
/**
* Enhanced constructor which takes the FRACTIONS in degress from 0.0f to
* 360.0f and also an GIVEN_OFFSET in degrees around the rotation CENTER
*
* #param USE_DEGREES
* #param CENTER
* #param GIVEN_OFFSET
* #param GIVEN_FRACTIONS
* #param GIVEN_COLORS
* #throws IllegalArgumentException
*/
public ConicalGradientPaint(final boolean USE_DEGREES, final java.awt.geom.Point2D CENTER, final float GIVEN_OFFSET, final float[] GIVEN_FRACTIONS, final java.awt.Color[] GIVEN_COLORS) throws IllegalArgumentException {
// Check that fractions and colors are of the same size
if (GIVEN_FRACTIONS.length != GIVEN_COLORS.length) {
throw new IllegalArgumentException("Fractions and colors must be equal in size");
}
final java.util.ArrayList<Float> FRACTION_LIST = new java.util.ArrayList<Float>(GIVEN_FRACTIONS.length);
final float OFFSET;
if (USE_DEGREES) {
final double DEG_FRACTION = 1f / 360f;
if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), -0.5) == 0) {
OFFSET = -0.5f;
} else if (Double.compare((GIVEN_OFFSET * DEG_FRACTION), 0.5) == 0) {
OFFSET = 0.5f;
} else {
OFFSET = (float) (GIVEN_OFFSET * DEG_FRACTION);
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add((float) (fraction * DEG_FRACTION));
}
} else {
// Now it seems to work with rotation of 0.5f, below is the old code to correct the problem
// if (GIVEN_OFFSET == -0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly -0.5
// OFFSET = -0.49999f;
// }
// else if (GIVEN_OFFSET == 0.5)
// {
// // This is needed because of problems in the creation of the Raster
// // with a angle offset of exactly +0.5
// OFFSET = 0.499999f;
// }
// else
{
OFFSET = GIVEN_OFFSET;
}
for (float fraction : GIVEN_FRACTIONS) {
FRACTION_LIST.add(fraction);
}
}
// Check for valid offset
if (OFFSET > 0.5f || OFFSET < -0.5f) {
throw new IllegalArgumentException("Offset has to be in the range of -0.5 to 0.5");
}
// Adjust fractions and colors array in the case where startvalue != 0.0f and/or endvalue != 1.0f
final java.util.List<java.awt.Color> COLOR_LIST = new java.util.ArrayList<java.awt.Color>(GIVEN_COLORS.length);
COLOR_LIST.addAll(java.util.Arrays.asList(GIVEN_COLORS));
// Assure that fractions start with 0.0f
if (FRACTION_LIST.get(0) != 0.0f) {
FRACTION_LIST.add(0, 0.0f);
final java.awt.Color TMP_COLOR = COLOR_LIST.get(0);
COLOR_LIST.add(0, TMP_COLOR);
}
// Assure that fractions end with 1.0f
if (FRACTION_LIST.get(FRACTION_LIST.size() - 1) != 1.0f) {
FRACTION_LIST.add(1.0f);
COLOR_LIST.add(GIVEN_COLORS[0]);
}
// Recalculate the fractions and colors with the given offset
final java.util.Map<Float, java.awt.Color> FRACTION_COLORS = recalculate(FRACTION_LIST, COLOR_LIST, OFFSET);
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
// Sort the hashmap by fraction and add the values to the FRACION_LIST and COLOR_LIST
final java.util.SortedSet<Float> SORTED_FRACTIONS = new java.util.TreeSet<Float>(FRACTION_COLORS.keySet());
final java.util.Iterator<Float> ITERATOR = SORTED_FRACTIONS.iterator();
while (ITERATOR.hasNext()) {
final float CURRENT_FRACTION = ITERATOR.next();
FRACTION_LIST.add(CURRENT_FRACTION);
COLOR_LIST.add(FRACTION_COLORS.get(CURRENT_FRACTION));
}
// Set the values
this.CENTER = CENTER;
COLORS = COLOR_LIST.toArray(new java.awt.Color[]{});
// Prepare lookup table for the angles of each fraction
final int MAX_FRACTIONS = FRACTION_LIST.size();
this.FRACTION_ANGLES = new double[MAX_FRACTIONS];
for (int i = 0; i < MAX_FRACTIONS; i++) {
FRACTION_ANGLES[i] = FRACTION_LIST.get(i) * 360;
}
// Prepare lookup tables for the color stepsize of each color
RED_STEP_LOOKUP = new double[COLORS.length];
GREEN_STEP_LOOKUP = new double[COLORS.length];
BLUE_STEP_LOOKUP = new double[COLORS.length];
ALPHA_STEP_LOOKUP = new double[COLORS.length];
for (int i = 0; i < (COLORS.length - 1); i++) {
RED_STEP_LOOKUP[i] = ((COLORS[i + 1].getRed() - COLORS[i].getRed()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
GREEN_STEP_LOOKUP[i] = ((COLORS[i + 1].getGreen() - COLORS[i].getGreen()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
BLUE_STEP_LOOKUP[i] = ((COLORS[i + 1].getBlue() - COLORS[i].getBlue()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
ALPHA_STEP_LOOKUP[i] = ((COLORS[i + 1].getAlpha() - COLORS[i].getAlpha()) * INT_TO_FLOAT_CONST) / (FRACTION_ANGLES[i + 1] - FRACTION_ANGLES[i]);
}
}
/**
* Recalculates the fractions in the FRACTION_LIST and their associated
* colors in the COLOR_LIST with a given OFFSET. Because the conical
* gradients always starts with 0 at the top and clockwise direction you
* could rotate the defined conical gradient from -180 to 180 degrees which
* equals values from -0.5 to +0.5
*
* #param FRACTION_LIST
* #param COLOR_LIST
* #param OFFSET
* #return Hashmap that contains the recalculated fractions and colors after
* a given rotation
*/
private java.util.HashMap<Float, java.awt.Color> recalculate(final java.util.List<Float> FRACTION_LIST, final java.util.List<java.awt.Color> COLOR_LIST, final float OFFSET) {
// Recalculate the fractions and colors with the given offset
final int MAX_FRACTIONS = FRACTION_LIST.size();
final java.util.HashMap<Float, java.awt.Color> FRACTION_COLORS = new java.util.HashMap<Float, java.awt.Color>(MAX_FRACTIONS);
for (int i = 0; i < MAX_FRACTIONS; i++) {
// Add offset to fraction
final float TMP_FRACTION = FRACTION_LIST.get(i) + OFFSET;
// Color related to current fraction
final java.awt.Color TMP_COLOR = COLOR_LIST.get(i);
// Check each fraction for limits (0...1)
if (TMP_FRACTION <= 0) {
FRACTION_COLORS.put(1.0f + TMP_FRACTION + 0.0001f, TMP_COLOR);
final float NEXT_FRACTION;
final java.awt.Color NEXT_COLOR;
if (i < MAX_FRACTIONS - 1) {
NEXT_FRACTION = FRACTION_LIST.get(i + 1) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(i + 1);
} else {
NEXT_FRACTION = 1 - FRACTION_LIST.get(0) + OFFSET;
NEXT_COLOR = COLOR_LIST.get(0);
}
if (NEXT_FRACTION > 0) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, NEXT_COLOR, (int) ((NEXT_FRACTION - TMP_FRACTION) * 10000), (int) ((-TMP_FRACTION) * 10000));
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
}
} else if (TMP_FRACTION >= 1) {
FRACTION_COLORS.put(TMP_FRACTION - 1.0f - 0.0001f, TMP_COLOR);
final float PREVIOUS_FRACTION;
final java.awt.Color PREVIOUS_COLOR;
if (i > 0) {
PREVIOUS_FRACTION = FRACTION_LIST.get(i - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(i - 1);
} else {
PREVIOUS_FRACTION = FRACTION_LIST.get(MAX_FRACTIONS - 1) + OFFSET;
PREVIOUS_COLOR = COLOR_LIST.get(MAX_FRACTIONS - 1);
}
if (PREVIOUS_FRACTION < 1) {
final java.awt.Color NEW_FRACTION_COLOR = getColorFromFraction(TMP_COLOR, PREVIOUS_COLOR, (int) ((TMP_FRACTION - PREVIOUS_FRACTION) * 10000), (int) (TMP_FRACTION - 1.0f) * 10000);
FRACTION_COLORS.put(1.0f, NEW_FRACTION_COLOR);
FRACTION_COLORS.put(0.0f, NEW_FRACTION_COLOR);
}
} else {
FRACTION_COLORS.put(TMP_FRACTION, TMP_COLOR);
}
}
// Clear the original FRACTION_LIST and COLOR_LIST
FRACTION_LIST.clear();
COLOR_LIST.clear();
return FRACTION_COLORS;
}
/**
* With the START_COLOR at the beginning and the DESTINATION_COLOR at the
* end of the given RANGE the method will calculate and return the color
* that equals the given VALUE. e.g. a START_COLOR of BLACK (R:0, G:0, B:0,
* A:255) and a DESTINATION_COLOR of WHITE(R:255, G:255, B:255, A:255) with
* a given RANGE of 100 and a given VALUE of 50 will return the color that
* is exactly in the middle of the gradient between black and white which is
* gray(R:128, G:128, B:128, A:255) So this method is really useful to
* calculate colors in gradients between two given colors.
*
* #param START_COLOR
* #param DESTINATION_COLOR
* #param RANGE
* #param VALUE
* #return Color calculated from a range of values by given value
*/
public java.awt.Color getColorFromFraction(final java.awt.Color START_COLOR, final java.awt.Color DESTINATION_COLOR, final int RANGE, final int VALUE) {
final float SOURCE_RED = START_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float SOURCE_GREEN = START_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float SOURCE_BLUE = START_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float SOURCE_ALPHA = START_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float DESTINATION_RED = DESTINATION_COLOR.getRed() * INT_TO_FLOAT_CONST;
final float DESTINATION_GREEN = DESTINATION_COLOR.getGreen() * INT_TO_FLOAT_CONST;
final float DESTINATION_BLUE = DESTINATION_COLOR.getBlue() * INT_TO_FLOAT_CONST;
final float DESTINATION_ALPHA = DESTINATION_COLOR.getAlpha() * INT_TO_FLOAT_CONST;
final float RED_DELTA = DESTINATION_RED - SOURCE_RED;
final float GREEN_DELTA = DESTINATION_GREEN - SOURCE_GREEN;
final float BLUE_DELTA = DESTINATION_BLUE - SOURCE_BLUE;
final float ALPHA_DELTA = DESTINATION_ALPHA - SOURCE_ALPHA;
final float RED_FRACTION = RED_DELTA / RANGE;
final float GREEN_FRACTION = GREEN_DELTA / RANGE;
final float BLUE_FRACTION = BLUE_DELTA / RANGE;
final float ALPHA_FRACTION = ALPHA_DELTA / RANGE;
//System.out.println(DISTANCE + " " + CURRENT_FRACTION);
return new java.awt.Color(SOURCE_RED + RED_FRACTION * VALUE, SOURCE_GREEN + GREEN_FRACTION * VALUE, SOURCE_BLUE + BLUE_FRACTION * VALUE, SOURCE_ALPHA + ALPHA_FRACTION * VALUE);
}
#Override
public java.awt.PaintContext createContext(final java.awt.image.ColorModel COLOR_MODEL, final java.awt.Rectangle DEVICE_BOUNDS, final java.awt.geom.Rectangle2D USER_BOUNDS, final java.awt.geom.AffineTransform TRANSFORM, final java.awt.RenderingHints HINTS) {
final java.awt.geom.Point2D TRANSFORMED_CENTER = TRANSFORM.transform(CENTER, null);
return new ConicalGradientPaintContext(TRANSFORMED_CENTER);
}
#Override
public int getTransparency() {
return java.awt.Transparency.TRANSLUCENT;
}
private final class ConicalGradientPaintContext implements java.awt.PaintContext {
final private java.awt.geom.Point2D CENTER;
public ConicalGradientPaintContext(final java.awt.geom.Point2D CENTER) {
this.CENTER = new java.awt.geom.Point2D.Double(CENTER.getX(), CENTER.getY());
}
#Override
public void dispose() {
}
#Override
public java.awt.image.ColorModel getColorModel() {
return java.awt.image.ColorModel.getRGBdefault();
}
#Override
public java.awt.image.Raster getRaster(final int X, final int Y, final int TILE_WIDTH, final int TILE_HEIGHT) {
final double ROTATION_CENTER_X = -X + CENTER.getX();
final double ROTATION_CENTER_Y = -Y + CENTER.getY();
final int MAX = FRACTION_ANGLES.length;
// Create raster for given colormodel
final java.awt.image.WritableRaster RASTER = getColorModel().createCompatibleWritableRaster(TILE_WIDTH, TILE_HEIGHT);
// Create data array with place for red, green, blue and alpha values
int[] data = new int[(TILE_WIDTH * TILE_HEIGHT * 4)];
double dx;
double dy;
double distance;
double angle;
double currentRed = 0;
double currentGreen = 0;
double currentBlue = 0;
double currentAlpha = 0;
for (int py = 0; py < TILE_HEIGHT; py++) {
for (int px = 0; px < TILE_WIDTH; px++) {
// Calculate the distance between the current position and the rotation angle
dx = px - ROTATION_CENTER_X;
dy = py - ROTATION_CENTER_Y;
distance = Math.sqrt(dx * dx + dy * dy);
// Avoid division by zero
if (distance == 0) {
distance = 1;
}
// 0 degree on top
angle = Math.abs(Math.toDegrees(Math.acos(dx / distance)));
if (dx >= 0 && dy <= 0) {
angle = 90.0 - angle;
} else if (dx >= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy >= 0) {
angle += 90.0;
} else if (dx <= 0 && dy <= 0) {
angle = 450.0 - angle;
}
// Check for each angle in fractionAngles array
for (int i = 0; i < (MAX - 1); i++) {
if ((angle >= FRACTION_ANGLES[i])) {
currentRed = COLORS[i].getRed() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * RED_STEP_LOOKUP[i];
currentGreen = COLORS[i].getGreen() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * GREEN_STEP_LOOKUP[i];
currentBlue = COLORS[i].getBlue() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * BLUE_STEP_LOOKUP[i];
currentAlpha = COLORS[i].getAlpha() * INT_TO_FLOAT_CONST + (angle - FRACTION_ANGLES[i]) * ALPHA_STEP_LOOKUP[i];
continue;
}
}
// Fill data array with calculated color values
final int BASE = (py * TILE_WIDTH + px) * 4;
data[BASE + 0] = (int) (currentRed * 255);
data[BASE + 1] = (int) (currentGreen * 255);
data[BASE + 2] = (int) (currentBlue * 255);
data[BASE + 3] = (int) (currentAlpha * 255);
}
}
// Fill the raster with the data
RASTER.setPixels(0, 0, TILE_WIDTH, TILE_HEIGHT, data);
return RASTER;
}
}
}
}

Text rendering with lwjgl

I have a png font, and I can correctly get the row/ column of each letter the problem is what to with that information. Each character is 8 by 8. Here is the code I have so far.
If anyone could give me some help or even just some advice it would be greatly appreciated.
private double xsize, ysize, x, y, rotate, xh, yh;
private int lxpos, lypos;
private Texture texture;
String text;
public TextRenderer(int fontsize, int xlocation, int ylocation,
int rotates, String path, String Text) {
text = Text;
rotate = rotates;
setXsize(fontsize);
ysize = fontsize;
x = xlocation;
y = ylocation;
setXh(getXsize() / 2);
yh = ysize / 2;
try {
texture = TextureLoader.getTexture(".PNG", new FileInputStream(
new File(path)));
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
texture.bind();
update();
}
public void update() {
char[] c = text.toCharArray();
int letter;
// 16 collumns 16 rows
for (int i = 0; i < c.length; i++) {
letter = c[i];
System.out.println(c[i]);
lypos = letter % 16;
lypos++;
System.out.println("Collumn :" + lypos);
lxpos = letter / 16;
System.out.println("Row :" + lxpos);
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glPushMatrix();
GL11.glTranslated(x, y, 0);
GL11.glTranslatef(10.0f, 10.5f, -0.0f); // back to previous position
GL11.glRotated(rotate, 0.0f, 0.0f, -1.0f); // rotate
GL11.glTranslatef(-10.0f, -10.5f, 0.0f); // to the origin
GL11.glTranslated(-x, -y, 0);
// above is for movement/rotation of text
// 128 px total
lxpos = lxpos * 8;
lxpos = lxpos * 8;
int startx = lxpos * 8;
int starty = lypos * 8;
double endx = startx + 8;
double endy = starty + 8;
GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2d(startx, starty);
GL11.glVertex2d(x - getXh(), y - yh);
GL11.glTexCoord2d(startx, endy);
GL11.glVertex2d(x - getXh(), y + yh);
GL11.glTexCoord2d(endx, endy);
GL11.glVertex2d(x + getXh(), y + yh);
GL11.glTexCoord2d(endx, starty);
GL11.glVertex2d(x + getXh(), y - yh);
GL11.glEnd();
GL11.glPopMatrix();
GL11.glDisable(GL11.GL_TEXTURE_2D);

Here is what I did:
public class Fsc {
public static Fsc cA = new Fsc((XCOORDINSHEET), (XCOORDINSHEET), (WIDTHOFCHAR), (HEIGHTOFCHAR));
etc...
public int ix, iy, width, height;
public Fsc(int ixa, int iya, int widtha, int heighta) {
ix = ixa;
iy = iya;
width = widtha;
height = heighta;
}
public void render(int xa, int ya, float scale) {
int x2 = ix + width;
int y2 = iy + height;
glBegin(GL_QUADS);
glTexCoord2f(ix, iy);
glVertex2f(xa, ya);
glTexCoord2f(x2, iy);
glVertex2f(xa + width * scale, ya);
glTexCoord2f(x2, y2);
glVertex2f(xa + width * scale, ya + height * scale);
glTexCoord2f(ix, y2);
glVertex2f(xa, ya + height * scale);
glEnd();
}
}
public class Fontsheet {
public int sheet;
public Fontsheet(String location) {
sheet = ImagingTools.glLoadTextureLinear(location);
}
public void render(int x, int y, float scale, String text) {
glEnable(GL_TEXTURE_RECTANGLE_ARB);
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, sheet);
float lwidth = 0;
int x2 = x;
for(int i = 0; i < text.length(); i++) {
char c = text.charAt(i);
x2 += lwidth;
switch(c) {
case 'A':
Fsc.cA.render(x2, y2, scale);lwidth = Fsc.cA.width * scale;
break;
case 'B': etc...
}
}
glBindTexture(GL_TEXTURE_RECTANGLE_ARB, 0);
glDisable(GL_TEXTURE_RECTANGLE_ARB);
}
}
Sorry for it not being formatted. I know for a fact that it works because I use it actively. I may have forgot a bit of code when copying it over. If it doesn't work for you, just tell me.
Hope it helps you.