problem with building a texture from matrix

OpenGL OpenGL: Basic Coding
1

I want to build a texture from matrix, and then send it to a shader for computing.

for experiment, I constructed my matrix like the following:


for(int h = 0; h < height; h++)
  for(int w = 0; w < width; w++)
  {
    id[h][w][0] = 0;
    id[h][w][1] = 1;
    id[h][w][2] = 2;
    id[h][w][3] = 3;
  }

and then use the glTexImage2D function call like this:


glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );  
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, id);

I used gDEBugger to check the value in the texture, and found some confusing results like the attached image. I cannot find any value equals 0, 1, 2, or 3. it is really confusing.

2

Try using a 1 dimentional array.