texCoordPointer not working in lwjgl - opengl

Question

I've been having problems storing texture coordinate points in a VBO, and then telling OpenGL to use it when it's time to render. In the code below, what I should be getting is a nice 16x16 texture on a square I am making using quads. However what I do get is the first top left pixel of the image instead which is red, so I get a big red square. Please tell me what I am doing wrong in great detail.
public void start() {
try {
Display.setDisplayMode(new DisplayMode(800,600));
Display.create();
} catch (LWJGLException e) {
e.printStackTrace();
System.exit(0);
}
// init OpenGL
GL11.glMatrixMode(GL11.GL_PROJECTION);
GL11.glLoadIdentity();
GL11.glOrtho(0, 800, 0, 600, 1, -1);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
glEnable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glLoadIdentity();
//loadTextures();
TextureManager.init();
makeCube();
// init OpenGL here
while (!Display.isCloseRequested()) {
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
// render OpenGL here
renderCube();
Display.update();
}
Display.destroy();
}
public static void main(String[] argv) {
Screen screen = new Screen();
screen.start();
}
int cube;
int texture;
private void makeCube() {
FloatBuffer cubeBuffer;
FloatBuffer textureBuffer;
//Tried using 0,0,16,0,16,16,0,16 for textureData did not work.
float[] textureData = new float[]{
0,0,
1,0,
1,1,
0,1};
textureBuffer = BufferUtils.createFloatBuffer(textureData.length);
textureBuffer.put(texture);
textureBuffer.flip();
texture = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, texture);
glBufferData(GL_ARRAY_BUFFER, textureBuffer, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
float[] cubeData = new float[]{
/*Front Face*/
100, 100,
100 + 200, 100,
100 + 200, 100 + 200,
100, 100 + 200};
cubeBuffer = BufferUtils.createFloatBuffer(cubeData.length);
cubeBuffer.put(cubeData);
cubeBuffer.flip();
cube = glGenBuffers();
glBindBuffer(GL_ARRAY_BUFFER, cube);
glBufferData(GL_ARRAY_BUFFER, cubeBuffer, GL_STATIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
private void renderCube(){
TextureManager.texture.bind();
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
glBindBuffer(GL_ARRAY_BUFFER, texture);
glTexCoordPointer(2, GL_FLOAT, 0, 0);
glBindBuffer(GL_ARRAY_BUFFER, cube);
glVertexPointer(2, GL_FLOAT, 0, 0);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glDrawArrays(GL_QUADS, 0, 4);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}

Answer 1

I believe your problem is in the argument to textureBuffer.put() in this code fragment:
textureBuffer = BufferUtils.createFloatBuffer(textureData.length);
textureBuffer.put(texture);
textureBuffer.flip();
texture is a variable of type int, which has not even been initialized yet. You later use it as a buffer name. The argument should be textureData instead:
textureBuffer.put(textureData);
I normally try to focus on functionality over style when answering questions here, but I can't help it this time: IMHO, texture is a very unfortunate name for a buffer name. It's not only a style and readability question. If you used descriptive names for the variables, you most likely would have spotted this problem immediately.
Say you named the variable for the buffer name bufferId (I call object identifiers "id", even though the official OpenGL terminology is "name"), and the buffer holding the texture coordinates textureCoordBuf. The statement in question would then become:
textureCoordBuf.put(bufferId);
which would jump out as highly suspicious from even a very superficial look at the code.