Develop Reference

Blue/black borders around textures: OpenGL?

I have had this bug for awhile now. I can't seem to get rid of it. I am thinking I may just have to draw my quads as normal rectangles; and create the illusion they are "rotated" when they aren't (using the textures).
Anyway, as you can see from the image, there are blue borders around all my tiles. I can't seem to get them to go away. I have tried other tilesheets and the same problem appears - except sometimes it's a black border.
I will post a decent bit of code - just so you have all the resources necessary to understand what I am doing.
My OpenGL setup code:
//******** SET UP OPENGL *******
public void setUpOpenGL() {
GL11.glEnable(GL11.GL_TEXTURE_2D);
GL11.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);
// enable alpha blending
GL11.glEnable(GL11.GL_BLEND);
GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 800, 0, 600, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
}
Drawing code:
#Override
public void drawTile(int tileX, int tileY, Texture atlas) {
int tileXcoord, tileYcoord;
tileXcoord = (tileX - tileY) * (TILE_XHALF); // TILE_WIDTH = 128
tileYcoord = (tileX + tileY) * (TILE_YHALF); // TILE_HEIGHT = 64
atlas.bind();
GL11.glColor3f(255, 255, 255);
GL11.glBegin(GL11.GL_QUADS);
{
setTextureCoordinates(1);
GL11.glVertex2f(tileXcoord, tileYcoord);
setTextureCoordinates(2);
GL11.glVertex2f(tileXcoord + TILE_XHALF, tileYcoord + TILE_YHALF);
setTextureCoordinates(3);
GL11.glVertex2f(tileXcoord + (TILE_XHALF * 2), tileYcoord);
setTextureCoordinates(4);
GL11.glVertex2f(tileXcoord + TILE_XHALF, tileYcoord - TILE_YHALF);
}
GL11.glEnd();
}
//***** SET TEXTURE COORDINATES *****
public void setTextureCoordinates(int pos) {
Rectangle rect = textureAtlas.getTexture(ID);
float x = rect.getX(), y = rect.getY();
float height = rect.getHeight(), width = rect.getWidth();
switch (pos) {
case 1 :
GL11.glTexCoord2f(x, y + (height / 2));
//GL11.glTexCoord2f(0.0f, 0.03125f);
//GL11.glTexCoord2f(0.0f, 0.5f);
break;
case 2:
GL11.glTexCoord2f(x + (width / 2), y + height);
//GL11.glTexCoord2f(0.03125f, 0.0625f);
//GL11.glTexCoord2f(0.5f, 1f);
break;
case 3:
GL11.glTexCoord2f(x + width, y + (height / 2));
//GL11.glTexCoord2f(0.0625f, 0.03125f);
//GL11.glTexCoord2f(1f, 0.5f);
break;
case 4:
GL11.glTexCoord2f(x + (width / 2), y);
//GL11.glTexCoord2f(0.03125f, 0.0f);
//GL11.glTexCoord2f(0.5f, 0.0f);
break;
}
}
Where drawing code gets its coordinates from (gridW = 9, gridH = 9, tilePixelWidth = 128, tilePixelHeight = 64, tilePercentOfWidth/Height comes out too 0.0625; total image resolution = 2048 x 1024):
//**** GET ID SPECIFIC TEXTURE CELL ******
public Rectangle getTexture(int id) {
int columnNumber = (int)(id % gridW); // Column of texture (using MOD so I can get textures beyond next column [next row])
int rowNumber = (int)(id / gridH); // Row number for texture
// TODO: Get texture selection working!
// Create bounding box
float tilePercentOfWidth = this.tilePixelWidth / this.tPWidth;
float tilePercentOfHeight = this.tilePixelHeight / this.tPHeight;
float boxX = (columnNumber * (tilePixelWidth / tPWidth));
float boxY = (rowNumber * (tilePixelHeight / tPHeight));
float boxWidth = tilePercentOfWidth;
float boxHeight = tilePercentOfHeight;
// End bounding box creation
Rectangle textureBounds = new Rectangle (boxX, boxY, boxWidth, boxHeight);
return textureBounds;
}

LWJGL Texture Unbinding

I'm currently working on a simple textured rectangle class using LWJGL (GL11). This is what I have so far in the draw method.
glEnable(GL_TEXTURE_2D);
color.bind();
glBegin(GL_QUADS);
t.bind();
if (centered)
{
glTexCoord2d(0, 0);
glVertex2d(x - (width / 2), y - (height / 2));
glTexCoord2d(t.getWidth(), 0);
glVertex2d(x + (width / 2), y - (height / 2));
glTexCoord2d(t.getWidth(), t.getHeight());
glVertex2d(x + (width / 2), y + (height / 2));
glTexCoord2d(0, t.getHeight());
glVertex2d(x - (width / 2), y + (height / 2));
}
else
{
glTexCoord2d(0, 0);
glVertex2d(x, y);
glTexCoord2d(t.getWidth(), 0);
glVertex2d(x + width, y);
glTexCoord2d(t.getWidth(), t.getHeight());
glVertex2d(x + width, y + height);
glTexCoord2d(0, t.getHeight());
glVertex2d(x, y + height);
}
glEnd();
glBindTexture(GL_TEXTURE_2D, 0);
glDisable(GL_TEXTURE_2D);
The problem is with the second to last line (glBindTexture(GL_TEXTURE_2D, 0)). If I leave this on, the image will display for a split second (probably one frame) and then turn solid white. If I comment this out, it will display, but always displays the last texture that was loaded. Any ideas?

I think it's because you are binding your texture between the glBegin() and glEnd() calls. This is invalid. I'm guessing when you leave the glBindTexture(GL_TEXTURE_2D, 0) call off, then the binding is taking effect the next frame. Not sure why it would work for one frame, though.
You can use glGetError to see if there are any errors generated.

LWJGL 2D Hud Just Wont Budge

For some reason I cannot fo the life of me figuire out what i'm doing wrong here. I am tring to render a 2d orthographic hud ontop of my 3d stuff which is rendered via shaders not draw calls. I've spent almost 8 hours and well I suck, please help. There are no errors in the console!
EngineWindow.bindAsRenderTarget(); //Set render target to display.
glDepthMask(false);
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_CLAMP);
glEnable(GL_BLEND);
glEnable(GL_TEXTURE_2D);
glPushMatrix();
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, width, height, 0, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
System.out.println(this.x + " " + this.y + " " + this.width + " " + this.height); //Its at the right position too.
GL13.glActiveTexture(GL13.GL_TEXTURE0);
texture.bind(); //Binds blue texture with writing.
glBegin(GL_QUADS);
glVertex2i(x, y);
glTexCoord2f(0f, 0f);
glVertex2i(x, y+height);
glTexCoord2f(0f, 1f);
glVertex2i(x+width, y+height);
glTexCoord2f(1f, 1f);
glVertex2i(x+width, y);
glTexCoord2f(1f, 0f);
glEnd();
glPopMatrix();
glDepthFunc(GL_LESS);
glDepthMask(true);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glDisable(GL_BLEND);
glEnable(GL_DEPTH_CLAMP);

Texture not rotating LWJGL

I am using the LWJGL and Slick-Util libraries in an attempt to rotate a texture.
Here is my code I'm using to try and rotate a texture.
GL11.glBegin(GL11.GL_QUADS);
GL11.glPushMatrix();
GL11.glTranslatef(x, y, 0);
GL11.glRotatef(r, 1, 1, 0);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture.getTextureID());
GL11.glTexCoord2f(0, 0);
GL11.glVertex2f(x, y);
GL11.glTexCoord2f(1, 0);
GL11.glVertex2f(x + texture.getTextureWidth(), y);
GL11.glTexCoord2f(1, 1);
GL11.glVertex2f(x + texture.getTextureWidth(), y + texture.getTextureHeight());
GL11.glTexCoord2f(0, 1);
GL11.glVertex2f(x, y + texture.getTextureHeight());
GL11.glPopMatrix();
GL11.glEnd();
It draws the texture perfectly fine at the x and y locations given, but when I pass in a degree, it does not rotate and just draws as if the rotation was zero.
Does anyone know what I'm doing wrong? Thank you in advance.
Edit:
When I run this code with an 'r' of 180 or any other degree. This is what my screen looks like.
The red circle image looks exactly like that as a regular un-rotated image.

I know it is a bit egotistical to answer your own questions, but after much research I have finally found my answer. Here is a working method that will rotate a slick-util texture according to an 'r' given in degrees.
public static void drawTexture(Texture texture, int x, int y, int r)
{
int width = texture.getTextureWidth();
int height = texture.getTextureHeight();
GL11.glTranslatef(x + width / 2, y + height / 2, 0);
GL11.glRotatef(r, 0, 0, 1);
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture.getTextureID());
GL11.glBegin(GL11.GL_QUADS);
GL11.glTexCoord2f(0, 0);
GL11.glVertex3f(-width / 2, -height / 2, 0);
GL11.glTexCoord2f(1, 0);
GL11.glVertex3f(width / 2, -height / 2, 0);
GL11.glTexCoord2f(1, 1);
GL11.glVertex3f(width / 2, height / 2, 0);
GL11.glTexCoord2f(0, 1);
GL11.glVertex3f(-width / 2, height / 2, 0);
GL11.glEnd();
GL11.glLoadIdentity();
}

Why does gluProject not give the correct screen space coordinates with LWJGL

So I'm using gluProject to take the 3d coordinates and tell me where on the screen they rendered. The problem is I don't get the same coordinates with gluProject and where they actually ended up rendering. The weird part is that if the difference between the x, y, and z of the camera and the point i'm testing are equal (e.g. camera at 5,3,4 and point at 2,0,1) it gives the correct values. I'm using gluLookAt() for camera transforms. I have confirmed that the same matrices that I use for rendering are being passed in to gluProject. Below is my rendering code, camera.look(), and my part with gluProject:
Rendering:
glEnable(GL_LIGHTING);
glEnable(GL_NORMAL_ARRAY);
glViewport(0, 0, Display.getHeight(), Display.getHeight());
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(90.0f, 1, .1f, 1000f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
cam.look();
for (Cube cube : cubes) {
cube.draw();
}
grid.draw();
Camera.look():
void look() {
calcPoints(xAng, yAng);
gluLookAt(x, y, z, x + dx, y + dy, z + dz, 0, 1, 0);
}
part with gluProject:
glViewport(0, 0, Display.getHeight(), Display.getHeight());
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(90.0f, 1, .1f, 1000f);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
cam.look();
modelview = BufferUtils.createFloatBuffer(16); //floatbuffers, defined earlier
projection = BufferUtils.createFloatBuffer(16);
viewport = BufferUtils.createIntBuffer(16);
FloatBuffer result = BufferUtils.createFloatBuffer(3);
glGetFloat(GL_MODELVIEW_MATRIX, modelview);
glGetFloat(GL_PROJECTION_MATRIX, projection);
glGetInteger(GL_VIEWPORT, viewport);
gluProject(1f, 0f, 0f, modelview, projection, viewport, result);
//Utils.printFloatBuffer(projection);
//Utils.printFloatBuffer(modelview);
System.out.println(result.get(0) + " " + result.get(1) + " " + result.get(2));

Maybe try having the up vector at a right angle to the camera direction and position instead of (0, 1, 0) constantly.