LWJGL Forum

Hello there!

For my application I need a highly customised shader. Started off by writing my shaders and they compiled fine. All the rest however confuses me, and I ended up with code that executes but does not draw anything. I am cluesless as to why and would be very happy if a pro could go through my code.
What I have attached is a very short (but executable) version of my code - but it has the same problem...

Thanks in advance!
My experience with forums is usually that I don't get any answer - leaving me wondering, whether others don't know the answer either or whether it's apparent in their eyes. So any kind of answer would be of some help...


import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL20.*;

public class LWJGLGraphics
{
private static final String BumpMapVertexShader =
"uniform mat4 normal_matrix;\n"
+ "uniform mat4 proj_matrix;\n"
+ "attribute vec4 aPosition;\n"
+ "void main() {\n"
+ "  gl_Position = proj_matrix * normal_matrix * aPosition;\n"
+ "}\n";
private static final String BumpMapFragmentShader =
"void main() {\n"
+ "  gl_FragColor = vec4(1,0.5,0.0,1);\n"
+ "}\n";

private static final int FLOAT_SIZE_BYTES = 4;
private static final int INT_SIZE_BYTES = 4;
private static final int SHORT_SIZE_BYTES = 2;

private static int BumpmapProgram;
private static int mProjMatrixHandle;
private static int muNOMatrixHandle;
private static int maPositionHandle;

public static void main(String[] argv)
{
try
{
init(640, 480, "Test");
}
catch(LWJGLException e)
{
e.printStackTrace();
System.exit(0);
}
while(!Display.isCloseRequested())
{
drawColorfulRectangle(25,25);
Display.update();
}
Display.destroy();
}

public static void drawColorfulRectangle(int cx, int cy)
{
// USE MY SHADERS
glUseProgram(BumpmapProgram);
// Define vertices (of a quad)
IntBuffer vert = makeIntBuffer(new int[] { 0,10,-10,
   10, 0,-10,
    0, 0,-10});
vert.position(0);
glEnableVertexAttribArray(maPositionHandle);
glVertexAttribPointer(maPositionHandle, 3, false, false, 3 * INT_SIZE_BYTES, vert);
// index buffer
ShortBuffer Primitives = makeShortBuffer(new short[] { 0, 1, 2 });
glDrawElements(GL_TRIANGLES, Primitives);
}

private static void init(int width, int height, String title) throws LWJGLException
{
// WINDOW STUFF
int hw = width / 2;
int hh = height / 2;
Display.setLocation(Display.getDisplayMode().getWidth() / 2 - hw, Display.getDisplayMode().getHeight() / 2 - hh);
Display.setDisplayMode(new DisplayMode(width, height));
Display.setTitle(title);
Display.create();

// CREATE, COMPILE SHADERS, PROGRAM
BumpmapProgram = createProgram(BumpMapVertexShader, BumpMapFragmentShader);
glValidateProgram(BumpmapProgram);

// GET POINTERS TO ATTRIBUTES, UNIFORMS
maPositionHandle = glGetAttribLocation(BumpmapProgram, "aPosition");
mProjMatrixHandle = glGetUniformLocation(BumpmapProgram, "proj_matrix");
muNOMatrixHandle = glGetUniformLocation(BumpmapProgram, "normal_matrix");

// PROJECTION STUFF (leave everything standard)
float[] normal_matrix = new float[16];
float[] proj_matrix = new float[16];
FloatBuffer Normal = makeFloatBuffer(normal_matrix);
FloatBuffer Projection = makeFloatBuffer(proj_matrix);
glGetFloat(GL_PROJECTION_MATRIX, Projection);
glGetFloat(GL_MODELVIEW_MATRIX, Normal);
glUniformMatrix4(mProjMatrixHandle, false, Projection);
glUniformMatrix4(muNOMatrixHandle, false, Normal);
}

private static int loadShader(int shaderType, String source)
{
int shader = glCreateShader(shaderType);
String errors;
if (shader != 0)
{
glShaderSource(shader, source);
glCompileShader(shader);
}
errors = glGetShaderInfoLog(shader, 1000).trim();
if (errors.length() > 0)
System.err.println("Shader errors: " + errors);
return shader;
}

private static int createProgram(String vertexSource, String fragmentSource)
{
String errors;
int vertexShader = loadShader(GL_VERTEX_SHADER, vertexSource);
int fragmentShader = loadShader(GL_FRAGMENT_SHADER, fragmentSource);
int program = glCreateProgram();
if (program != 0)
{
glAttachShader(program, vertexShader);
glAttachShader(program, fragmentShader);
glLinkProgram(program);
}
errors=glGetProgramInfoLog(BumpmapProgram, 1000).trim();
if(errors.length()>0)
System.err.println("Program errors:" + errors);
return program;
}

private static IntBuffer makeIntBuffer(int[] data)
{
int l = data.length;
IntBuffer I = ByteBuffer.allocateDirect(l * INT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asIntBuffer();
I.put(data);
I.flip();
return I;
}

private static ShortBuffer makeShortBuffer(short[] data)
{
int l = data.length;
ShortBuffer I = ByteBuffer.allocateDirect(l * SHORT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asShortBuffer();
I.put(data);
I.flip();
return I;
}

private static FloatBuffer makeFloatBuffer(float[] data)
{
int l = data.length;
FloatBuffer I = ByteBuffer.allocateDirect(l * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
I.put(data);
I.flip();
return I;
}
}


OK, problem solved.