Unable to get a simple OpenGL triangle to rotate - java

I have a method drawTriangle which is referenced in the display() method of an OpenGL program in JAVA.
public void drawTriangle(GL gl, int x1, int y1, int x2, int y2, int x3, int y3){
gl.glVertex2d(x1, y1);
gl.glVertex2d(x2, y2);
gl.glVertex2d(x3, y3);
}
I then call the triangle in Display()
public void display(GLAutoDrawable drawable){
GL gl = drawable.getGL();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(0.4f, 1.0f, 0.4f);
gl.glBegin(GL.GL_TRIANGLES);
gl.glPushMatrix();
drawTriangle(gl,0,0,0,20,100,10);
gl.glTranslatef(0f, 0f, 0f);
gl.glRotatef(90f, 0f, 0f, 1f);
gl.glPopMatrix();
}
This then draws a lovely red Triangle.
I can't change the position or rotation of the triangle.
It just spawns it here:

There are a few problems with the code. First of all, gl.glBegin(...) should be followed by gl.glEnd(). Keep the drawing functions, such as, drawTriangle(...) within these two, and any matrix operations outside.
public void display(GLAutoDrawable drawable)
{
GL gl = drawable.getGL();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(0.4f, 1.0f, 0.4f);
gl.glPushMatrix();
gl.glTranslatef(0f, 0f, 0f);
gl.glRotatef(90f, 0f, 0f, 1f);
gl.glBegin(GL.GL_TRIANGLES);
drawTriangle(gl,0,0,0,20,100,10);
gl.glEnd();
gl.glPopMatrix();
}

You're applying the transformation after rendering. This does not work!
first set up your matrices (i.e. do the transformation)
then render
finally popMatrix to restore the original matrix
i.e.:
public void display(GLAutoDrawable drawable)
{
GL gl = drawable.getGL();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glPushMatrix();
gl.glTranslatef(0f, 0f, 0f);
gl.glRotatef(90f, 0f, 0f, 1f);
gl.glBegin(GL.GL_TRIANGLES);
gl.glColor3f(0.4f, 1.0f, 0.4f);
drawTriangle(gl,0,0,0,20,100,10);
gl.glEnd();
gl.glPopMatrix();
}

My example rotates a quad, I assume that you're able to modify it to rotate a triangle:
https://gist.github.com/gouessej/3420e2b6f632efdddf98
It's quoted on Wikipedia and in the JogAmp wiki. Improve your Yacy/DuckDuckGo/IxQuick/Seeks skills next time ;)

Related

LWJGL - Why is my triangle getting smaller when I rotate it?

In LWJGL 3.2.1 I'm drawing a triangle using vertices and viewing it with a perspective (frustum) projection. I'm trying to use the triangle to orientate myself in 3D space to figure out where I am and how to direct myself. When I rotate the triangle, it gets smaller instead of rotating around the set point.
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(0, windowWidth, windowHeight, 0, 0, 100);
glMatrixMode(GL_MODELVIEW);
while (!glfwWindowShouldClose(window))
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glMatrixMode(GL_PROJECTION);
glRotatef(5f, 0f, 0f, 0f);
glMatrixMode(GL_MODELVIEW);
glBegin(GL_POLYGON);
glVertex3f(-0f, -0f, 0f);
glVertex3f(0f, 1f, 0f);
glVertex3f(1f, 1f, 0f);
glEnd();
glPopMatrix();
glfwSwapBuffers(window);
glfwPollEvents();
}
Am I rotating it incorrectly or something?

OpenGL ES - Too much work on main thread

I'm trying to render a 3D cube with different textures on each face (a dice), it works flawlessly when I only render the cube with one of the same image, but the cube doesn't even display and the following is thrown in the android monitor when I try to do the former:
Skipped 36 frames! The application may be doing too much work on its main thread.
After some research I'm aware that I could run this "heavy processing" in its own thread but I'm lost as to how to go about it. I'm relatively new to OpenGL rendering so I don't know whether my code is super optimal either.
I'm thinking I should run the Dice3D.java in another thread? This is the only class that doesn't extend or implement anything and through a little research I have found the class needs to implement runnable?
Any help in making this work would be great, thanks in advance!
Here are my classes:
OpenGLRenderer.java
public class OpenGLRenderer implements GLSurfaceView.Renderer {
private Context context;
private Dice3D dice3D;
public OpenGLRenderer(Context context, FrameLayout openGLLayout) {
this.context = context;
dice3D = new Dice3D(context);
GLSurfaceView glView = new GLSurfaceView(context);
glView.setRenderer(this);
//put to welcome layout
openGLLayout.addView(glView, new FrameLayout.LayoutParams(FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT));
}
private float mCubeRotation;
#Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f); // Set color's clear-value to black
gl.glClearDepthf(1.0f); // Set depth's clear-value to farthest
gl.glEnable(GL10.GL_DEPTH_TEST); // Enables depth-buffer for hidden surface removal
gl.glDepthFunc(GL10.GL_LEQUAL); // The type of depth testing to do
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST); // nice perspective view
gl.glShadeModel(GL10.GL_SMOOTH); // Enable smooth shading of color
gl.glDisable(GL10.GL_DITHER); // Disable dithering for better performance
// Setup Texture, each time the surface is created (NEW)
dice3D.loadTexture(gl); // Load images into textures (NEW)
gl.glEnable(GL10.GL_TEXTURE_2D); // Enable texture (NEW)
}
#Override
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -6.0f);
gl.glRotatef(mCubeRotation, 1.0f, 1.0f, 1.0f);
dice3D.draw(gl);
mCubeRotation -= 0.15f;
}
#Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
GLU.gluPerspective(gl, 45.0f, (float)width / (float)height, 0.1f, 100.0f);
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
}
}
Dice3D.java
public class Dice3D {
private FloatBuffer vertexBuffer; // Buffer for vertex-array
private FloatBuffer texBuffer; // Buffer for texture-coords-array (NEW)
private int numFaces = 6;
private int[] imageFileIDs = { // Image file IDs
R.drawable.one,
R.drawable.two,
R.drawable.three,
R.drawable.four,
R.drawable.five,
R.drawable.six
};
private int[] textureIDs = new int[numFaces];
private Bitmap[] bitmap = new Bitmap[numFaces];
// Constructor - Set up the buffers
public Dice3D(Context context) {
// Setup vertex-array buffer. Vertices in float. An float has 4 bytes
ByteBuffer vbb = ByteBuffer.allocateDirect(12 * 4 * numFaces);
vbb.order(ByteOrder.nativeOrder()); // Use native byte order
vertexBuffer = vbb.asFloatBuffer(); // Convert from byte to float
for (int face = 0; face < numFaces; face++) {
bitmap[face] = BitmapFactory.decodeStream(context.getResources().openRawResource(imageFileIDs[face]));
float[] vertices = { // Vertices for a face
-1.0f, -1.0f, 0.0f, // 0. left-bottom-front
1.0f, -1.0f, 0.0f, // 1. right-bottom-front
-1.0f, 1.0f, 0.0f, // 2. left-top-front
1.0f, 1.0f, 0.0f // 3. right-top-front
};
vertexBuffer.put(vertices); // Populate
}
vertexBuffer.position(0); // Rewind
float[] texCoords = { // Texture coords for the above face (NEW)
0.0f, 1.0f, // A. left-bottom (NEW)
1.0f, 1.0f, // B. right-bottom (NEW)
0.0f, 0.0f, // C. left-top (NEW)
1.0f, 0.0f // D. right-top (NEW)
};
// Setup texture-coords-array buffer, in float. An float has 4 bytes (NEW)
ByteBuffer tbb = ByteBuffer.allocateDirect(texCoords.length * 4 * numFaces);
tbb.order(ByteOrder.nativeOrder());
texBuffer = tbb.asFloatBuffer();
for (int face = 0; face < numFaces; face++) {
texBuffer.put(texCoords);
}
texBuffer.position(0);
}
// Draw the shape
public void draw(GL10 gl) {
gl.glFrontFace(GL10.GL_CCW); // Front face in counter-clockwise orientation
gl.glEnable(GL10.GL_CULL_FACE); // Enable cull face
gl.glCullFace(GL10.GL_BACK); // Cull the back face (don't display)
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); // Enable texture-coords-array (NEW)
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, texBuffer); // Define texture-coords buffer (NEW)
// front
gl.glPushMatrix();
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
// left
gl.glPushMatrix();
gl.glRotatef(270.0f, 0.0f, 1.0f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
// back
gl.glPushMatrix();
gl.glRotatef(180.0f, 0.0f, 1.0f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
// right
gl.glPushMatrix();
gl.glRotatef(90.0f, 0.0f, 1.0f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
// top
gl.glPushMatrix();
gl.glRotatef(270.0f, 1.0f, 0.0f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
// bottom
gl.glPushMatrix();
gl.glRotatef(90.0f, 1.0f, 0.0f, 0.0f);
gl.glTranslatef(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
gl.glPopMatrix();
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY); // Disable texture-coords-array
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisable(GL10.GL_CULL_FACE);
}
// Load an image into GL texture
public void loadTexture(GL10 gl) {
gl.glGenTextures(6, textureIDs, 0); // Generate texture-ID array for 6 IDs
// Generate OpenGL texture images
for (int face = 0; face < numFaces; face++) {
gl.glBindTexture(GL10.GL_TEXTURE_2D, textureIDs[face]);
// Build Texture from loaded bitmap for the currently-bind texture ID
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap[face], 0);
bitmap[face].recycle();
}
}
}
and finally my activity Welcome.java
public class Welcome extends AppCompatActivity {
LinearLayout l1,l2;
public Button btnsub;
Animation uptodown,downtoup;
#Override
protected void onCreate(Bundle savedInstanceState) {
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_welcome);
FrameLayout openGLLayout = (FrameLayout) findViewById(R.id.frameLayout1);
//creates an openGL surface and renders it to the framelayout in the activity layout
OpenGLRenderer gl3DView = new OpenGLRenderer(this, openGLLayout);
btnsub = (Button)findViewById(R.id.buttonsub);
btnsub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent test = new Intent(Welcome.this,DiceGame.class);
startActivity(test);
}
});
l1 = (LinearLayout) findViewById(R.id.l1);
l2 = (LinearLayout) findViewById(R.id.l2);
uptodown = AnimationUtils.loadAnimation(this,R.anim.uptodown);
downtoup = AnimationUtils.loadAnimation(this,R.anim.downtoup);
l1.setAnimation(uptodown);
l2.setAnimation(downtoup);
}
}
In terms of performance:
1) Learn OpenGL ES 2.0 and use shaders; it's a much cleaner API with a lot less messing about needed in the application and/or in the driver stack. All of the new APIs are shader-based, so this is a good thing to learn. I wouldn't consider using OpenGL ES 1.x for any new projects as it's a dead-end from a technology point of view.
(2) Once using OpenGL ES 2.0 or newer the use buffer objects for storing vertex data, and upload the data at the start of the application, nor per frame. It shouldn't really matter in this case (cube is very simple), but it's a good habit to get in to.

LWJGL - Switching from 3D to 2D to render text with NO external librarys

I want to render 2D quads on my screen by switching to a 2D scene then switching back to 3D.
I dont want to use any external librarys besides LWJGL.
This is what I got so far:
private static void renderLetter(char c, float x, float y) {
int character = c+1;
GL11.glPushMatrix();
setOrthoOn();
GL11.glTranslatef(x, y, 0);
float[] xy = game.getResourceManager().getSpriteSheets().get(fontSheet).getXYForCell(character);
float cellx = game.getResourceManager().getSpriteSheets().get(fontSheet).getCell_sizeX();
float celly = game.getResourceManager().getSpriteSheets().get(fontSheet).getCell_sizeY();
float xx = xy[0];
float yy = xy[1];
GL11.glBindTexture(GL11.GL_TEXTURE_2D, game.getResourceManager().getTextures().get(game.getResourceManager().getSpriteSheets().get(fontSheet).getTextureID()));
GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2f(xx, yy);
GL11.glVertex2f(0,0);
GL11.glTexCoord2f(xx+cellx, yy);
GL11.glVertex2f(fontSize,0);
GL11.glTexCoord2f(xx+cellx, yy+celly);
GL11.glVertex2f(fontSize,fontSize);
GL11.glTexCoord2f(xx, yy+celly);
GL11.glVertex2f(0,fontSize);
GL11.glEnd();
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
setOrthoOff();
GL11.glPopMatrix();
}
public static void setOrthoOn()
{
GL11.glDisable(GL11.GL_LIGHTING);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glClearDepth(1);
GL11.glViewport(0,0,1360,768);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 1360, 768, 0, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
}
public static void setOrthoOff()
{
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GLU.gluPerspective(game.getFieldOfView(), 1360f/768f, 0.1f, 1000);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glEnable(GL11.GL_DEPTH_TEST);
GL11.glDepthFunc(GL11.GL_LEQUAL);
GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);
}
the first method is to render a letter. what I am trying to do is by calling setOrthoOn switch to 2D rendering then render the quad then call setOrthoOff to switch back to 3D.
This code does nothing for me when I run it.. What am I doing wrong?
This should do it.
Note: some of the code may be extraneous. I'm not very experienced with OpenGL, but this worked for me. I would also recommend you import GL11 staticly. That way you don't have to type "GL11.BlaBlaBla", you can just type "BlaBlaBla".

How do i convert the DevIL in NEHE Lesson07 to Slick libraries?

I'm trying to learn how to use LWJGL libraries. Took me forever to find lessons. I eventually stumbled upon the NEHE lessons that teach OpenGL across many programming languages. I downloaded the LWJGL version of Lesson07 and noticed it was using DevIL for the images.
I asked a question on here earlier on what i should use instead of DevIL, and an informative user suggested that i go with Slick instead. I got past Lesson06 after tweaking it for a while, but now i am seriously stuck on Lesson07.
Specifically HERE:
private int[] loadTexture(String path) {
IntBuffer image = ByteBuffer.allocateDirect(4).order(ByteOrder.nativeOrder()).asIntBuffer();
IL.ilGenImages(1, image);
IL.ilBindImage(image.get(0));
IL.ilLoadImage(path);
IL.ilConvertImage(IL.IL_RGB, IL.IL_BYTE);
ByteBuffer scratch = ByteBuffer.allocateDirect(IL.ilGetInteger(IL.IL_IMAGE_WIDTH) * IL.ilGetInteger(IL.IL_IMAGE_HEIGHT) * 3);
IL.ilCopyPixels(0, 0, 0, IL.ilGetInteger(IL.IL_IMAGE_WIDTH), IL.ilGetInteger(IL.IL_IMAGE_HEIGHT), 1, IL.IL_RGB, IL.IL_BYTE, scratch);
// Create A IntBuffer For Image Address In Memory
IntBuffer buf = ByteBuffer.allocateDirect(12).order(ByteOrder.nativeOrder()).asIntBuffer();
GL11.glGenTextures(buf); // Create Texture In OpenGL
GL11.glBindTexture(GL11.GL_TEXTURE_2D, buf.get(0));
// Typical Texture Generation Using Data From The Image
// Create Nearest Filtered Texture
GL11.glBindTexture(GL11.GL_TEXTURE_2D, buf.get(0));
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB, IL.ilGetInteger(IL.IL_IMAGE_WIDTH),
IL.ilGetInteger(IL.IL_IMAGE_HEIGHT), 0, GL11.GL_RGB, GL11.GL_UNSIGNED_BYTE, scratch);
// Create Linear Filtered Texture
GL11.glBindTexture(GL11.GL_TEXTURE_2D, buf.get(1));
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR);
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL11.GL_RGB, IL.ilGetInteger(IL.IL_IMAGE_WIDTH),
IL.ilGetInteger(IL.IL_IMAGE_HEIGHT), 0, GL11.GL_RGB, GL11.GL_UNSIGNED_BYTE, scratch);
// Create MipMapped Texture
GL11.glBindTexture(GL11.GL_TEXTURE_2D, buf.get(2));
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR_MIPMAP_NEAREST);
GLU.gluBuild2DMipmaps(GL11.GL_TEXTURE_2D, 3, IL.ilGetInteger(IL.IL_IMAGE_WIDTH),
IL.ilGetInteger(IL.IL_IMAGE_HEIGHT), GL11.GL_RGB, GL11.GL_UNSIGNED_BYTE, scratch);
return new int[]{ buf.get(0), buf.get(1), buf.get(2) }; // Return Image Addresses In Memory
}
I've tried to get it working, tried substituting Slick stuff in, yet all i have tried has either crashed or led to a black screen.
What is the best way to do this with Slick?
This one was rather annoying. I think it was easier to convert than Lesson 06, but that could be because I was at least a little more used to it than I was in 06. It still took me all night to get this to work and I didn't figure it out until morning, though.
Here's my entire code. Lines are commented on the most annoying parts, along with some CODE commented to show what DIDN'T work. Any such code that was put in a comment is probably very fragmented so I'm not sure if you'll understand what I was trying to do, but I left it in anyway. The two places that I got stuck at are the two places with helpful comments and links.
package LWJGLTest2;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferInt;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.util.glu.GLU.*;
import java.io.IOException;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import org.lwjgl.BufferUtils;
import org.lwjgl.LWJGLException;
import org.lwjgl.input.Keyboard;
import org.lwjgl.input.Mouse;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.util.glu.GLU;
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
import org.newdawn.slick.util.ResourceLoader;
/**
*
* #author Jay
*/
public class LWJGLTest2 {
public static final int WIDTH = 640;
public static final int HEIGHT = 480;
public static final Logger LOGGER = Logger.getLogger(LWJGLTest2.class.getName());
float xrot;
float yrot;
float xspeed;
float yspeed;
float zpos = -5f;
boolean lp;
boolean fp;
boolean light;
final float[] AMBIENT = {.5f, .5f, .5f, 1f};
final float[] DIFFUSE = {1f, 1f, 1f, 1f};
final float[] LPOSITION = {0f, 0f, 2f, 1f};
int filter;
BufferedImage textureImage;
Texture texture[] = new Texture[3];
static {
try {
LOGGER.addHandler(new FileHandler("errors.log",true));
}
catch(IOException ex) {
LOGGER.log(Level.WARNING,ex.toString(),ex);
}
}
public static void main(String[] args) {
LWJGLTest2 main = null;
try {
main = new LWJGLTest2();
main.create();
main.run();
} catch (Exception ex) {
LOGGER.log(Level.SEVERE, ex.toString(), ex);
} finally {
if (main != null) {
main.destroy();
}
}
}
public void create() throws LWJGLException {
// Display
Display.setDisplayMode(new DisplayMode(WIDTH, HEIGHT));
Display.setFullscreen(false);
Display.setTitle("LWJGL Test");
Display.create();
// Keyboard
Keyboard.create();
// Mouse
Mouse.setGrabbed(false);
Mouse.create();
// OpenGL
initGL();
resizeGL();
}
public void destroy() {
Mouse.destroy();
Keyboard.destroy();
Display.destroy();
}
public void initGL() {
try {
loadTextures();
} catch (IOException ex) {
System.err.println(ex); System.exit(0);
}
glEnable(GL_TEXTURE_2D);
glShadeModel(GL_SMOOTH);
glClearColor(0f, 0f, 0f, 0.5f);
glClearDepth(1f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
//FloatBuffer scratch = BufferUtils.createFloatBuffer(8); // 4 for the values and 4 for the extra buffer
//scratch.put(AMBIENT);
ByteBuffer scratch = ByteBuffer.allocateDirect(16);
scratch.order(ByteOrder.nativeOrder());
//scratch.put(AMBIENT);
glLight(GL_LIGHT1, GL_AMBIENT, (FloatBuffer)scratch.asFloatBuffer().put(AMBIENT).flip()); // 3rd argument used to be only scratch
//scratch = ByteBuffer.allocateDirect(32).asFloatBuffer(); // reset the buffer to prevent an overflow
//scratch.put(DIFFUSE);
glLight(GL_LIGHT1, GL_DIFFUSE, (FloatBuffer)scratch.asFloatBuffer().put(AMBIENT).flip());
//scratch = ByteBuffer.allocateDirect(32).asFloatBuffer();
//scratch.put(LPOSITION);
glLight(GL_LIGHT1, GL_POSITION, (FloatBuffer)scratch.asFloatBuffer().put(AMBIENT).flip());
glEnable(GL_LIGHT1);
}
public void resizeGL() {
glViewport(0, 0, WIDTH, HEIGHT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45f, (float)WIDTH/(float)HEIGHT, 0.1f, 100f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
public void run() {
while (!Display.isCloseRequested() && !Keyboard.isKeyDown(Keyboard.KEY_ESCAPE)) {
if (Display.isVisible()) {
checkInput();
render();
Display.update();
}
}
}
public void checkInput() {
if (Keyboard.isKeyDown(Keyboard.KEY_L) && !lp) {
lp = true;
light = !light;
if (light)
glEnable(GL_LIGHTING);
else
glDisable(GL_LIGHTING);
}
if (!Keyboard.isKeyDown(Keyboard.KEY_L))
lp = false;
if (Keyboard.isKeyDown(Keyboard.KEY_F) && !fp) {
fp = true;
filter = (filter + 1) % 3;
}
if (!Keyboard.isKeyDown(Keyboard.KEY_F))
fp = false;
if (Keyboard.isKeyDown(Keyboard.KEY_PRIOR))
zpos -= 0.02f;
if (Keyboard.isKeyDown(Keyboard.KEY_NEXT))
zpos += 0.02f;
if (Keyboard.isKeyDown(Keyboard.KEY_UP))
xspeed -= 0.001f;
if (Keyboard.isKeyDown(Keyboard.KEY_DOWN))
xspeed += 0.001f;
if (Keyboard.isKeyDown(Keyboard.KEY_RIGHT))
yspeed -= 0.001f;
if (Keyboard.isKeyDown(Keyboard.KEY_LEFT))
yspeed += 0.001f;
}
public void render() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0f, 0f, zpos);
glRotatef(xrot, 1f, 0f, 0f);
glRotatef(yrot, 0f, 1f, 0f);
texture[filter].bind();
glBegin(GL_QUADS);
// Front Face
glNormal3f(0f, 0f, 1f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
// Back Face
glNormal3f(0f, 0f, -1f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
// Top Face
glNormal3f(0f, 1f, 0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
// Bottom Face
glNormal3f(0f, -1f, 0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
// Right face
glNormal3f(1f, 0f, 0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f, 1.0f, -1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, 1.0f, 1.0f); // Top Left Of The Texture and Quad
glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, 1.0f); // Bottom Left Of The Texture and Quad
// Left Face
glNormal3f(-1f, 0f, 0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f); // Bottom Left Of The Texture and Quad
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f); // Bottom Right Of The Texture and Quad
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f); // Top Right Of The Texture and Quad
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f); // Top Left Of The Texture and Quad
glEnd();
xrot += xspeed;
yrot += yspeed;
}
public void loadTextures() throws IOException {
//textureImage = ImageIO.read(this.getClass().getResourceAsStream("Crate.png"));
texture[0] = TextureLoader.getTexture("BMP", this.getClass().getResourceAsStream("Crate.bmp"), true, GL_NEAREST);
texture[1] = TextureLoader.getTexture("BMP", this.getClass().getResourceAsStream("Crate.bmp"), true, GL_LINEAR);
texture[2] = TextureLoader.getTexture("BMP", this.getClass().getResourceAsStream("Crate.bmp"), true);
//ByteBuffer scratch = ByteBuffer.wrap(((DataBufferByte)textureImage.getRaster().getDataBuffer()).getData());
//ByteBuffer scratch = ByteBuffer.allocateDirect(((DataBufferByte)textureImage.getRaster().getDataBuffer()).getData().length + 3);
/*
* The +3 in the last statement is important! Without it, you get this:
* SEVERE: java.lang.IllegalArgumentException: Number of remaining buffer
* elements is 0, must be at least 3. Because at most 3 elements can be
* returned, a buffer with at least 3 elements is required, regardless of
* actual returned element count
*/
//scratch.put(((DataBufferByte)textureImage.getRaster().getDataBuffer()).getData()); // RED
//scratch.rewind(); // NOW IT'S RED.
//for (int i = 0; i < scratch.limit(); ++i)
// System.out.println(scratch);
texture[2].bind();
//ByteBuffer scratch = ByteBuffer.allocateDirect(texture[2].getTextureData().length);
//scratch.order(ByteOrder.nativeOrder());
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
//GLU.gluBuild2DMipmaps(GL_TEXTURE_2D, 3, (int)texture[2].getWidth(), (int)texture[2].getHeight(), GL_RGB, GL_UNSIGNED_BYTE, (ByteBuffer)scratch.put(texture[2].getTextureData()).flip());
org.lwjgl.opengl.GL30.glGenerateMipmap(GL_TEXTURE_2D); /* http://slick.javaunlimited.net/viewtopic.php?t=2755
* Not sure if this worked properly, but I rather enjoy
* not crying so I'll just smile and nod.
* I went through a LOT of other options before I got this.
* I also tried using the trick I found at
* http://lwjgl.org/forum/index.php?action=printpage;topic=2233.0
* (used above, in initGL) but that didn't work either.
*/
}
}
This code has been run and FINALLY works. Using Slick-Util compresses it a LOT. You'll also notice that I changed the rate of change for the speeds; 0.01f was way too fast, so I put it to 0.001f instead. Hope this helps!
Links from my source code:
"Mipmapping"
"Why is adding of the light in lwjgl so difficult?"
You'll probably need to adapt the code to use the standard LWJGL image / texture loading features, at least up to the point of the glBindTexture() call. After that point I think you should be OK, it's all pretty standard OpenGL from that point.
There is some pretty decent example code here that demonstrates what you need to do:
http://lwjgl.org/wiki/index.php?title=Slick-Util_Library_-_Part_1_-_Loading_Images_for_LWJGL
I think the key lines of code you need are:
import org.newdawn.slick.opengl.Texture;
import org.newdawn.slick.opengl.TextureLoader;
...
Texture texture = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/image.png"));
...
GL11.glBind(texture.getTextureID());
In other words, I think it's actually a bit simpler than using DevIL.

OpenGL-ES Enabling orthographic mode 2D

I'm trying to have no size difference from sprites, if you increase the z to far away.
however i have no luck, it still gets smaller:
||EDIT||
I now have these methods
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
float _width = 320f;
float _height = 480f;
gl.glDisable(GL10.GL_DEPTH_TEST);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glOrthof(0, _width, 0, _height, 1, 100);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
// Load textures ,
gl.glEnable(GL10.GL_TEXTURE_2D);
for (int a = 0; a < squares.length; a++) {
squares[a].loadGLTexture(gl, context);
}
}
.
public void onDrawFrame(GL10 gl) {
//Clear Screen And Depth Buffer
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity(); //Reset The Current Modelview Matrix
gl.glTranslatef(.0f, 1.0f, locZ);
squares[0].draw(gl);
gl.glLoadIdentity();
gl.glTranslatef(0.5f, 0.f, locZ);
squares[1].draw(gl);
gl.glLoadIdentity();
gl.glTranslatef(-0.5f, -0.5f, locZ);
squares[2].draw(gl);
gl.glLoadIdentity();
gl.glTranslatef(-0.5f, -0.5f, locZ);
squares[3].draw(gl);
//change zvalues
if(locZ >= 4.0f){
speedZ *= -1.0f;
locZ = 3.9f;
}
else if(locZ <= -4.0){
speedZ *= -1.0f;
locZ = -3.9f;
}
locZ += speedZ;
}
I'm changing the z-values, and therefor the distance from the 'camera', and expecting that since I don't want to use perspective(orthographic mode), the sizes of the squares should stay constant. But they don't. Hope this helps some more.
You have bad glOrtho parameters:
gl.glOrthof(0, width, 0, height, 0.01f, 100.0f);
Or
gl.glOrthof(0, width, height, 0, 0.01f, 100.0f);
EDIT: forget to reset matrix - glLoadIdentity.
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
/* SET NEW PROJECTION HERE: ortho or perspective */
gl.glOrthof(0, _width, 0, _height, 0.001f, 100);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
/* SET NEW MODELVIEW MATRIX( space transformation ) HERE and DRAW YOUR STUFF */
//change zvalues
if(locZ >= 99.0f){
speedZ *= -1.0f;
locZ = 99.0f;
}
else if(locZ <= 1.0){
speedZ *= -1.0f;
locZ = 1.0f;
}
}
These steps have to be done before rendering 2D, resp. moving from 3D projection to 2D projection, not when creating texture or any object. Don't know much about public void onSurfaceCreated, but it doesn't seem to be part of rendering loop.
So the origin is in the middle of your GLSurfaceView, it's not a bad idea to do something like:
gl.glOrthof(-width/2, width/2, -height/2, height/2, 0.1f, 100.0f);
here you could have two methods; one to switch to orthoscopic view in which one openGLUnit = one screen pixel for drawing in 2d on screen. Then the next method switches it back to 3d drawing. Do your 2d drawing after rendering 3d and first call the switchToOrtho method and when your finished call the switchBackToFrustum method.
public void switchToOrtho() {
glDisable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrthof(0, self.view.bounds.size.width, 0, self.view.bounds.size.height, -5, 1); glMatrixMode(GL_MODELVIEW); glLoadIdentity();
}
public void switchBackToFrustum() {
glEnable(GL_DEPTH_TEST);
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
}

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