GL_TEXTURE_RECTANGLE with GLuint data?

[PrestoChung]

No matter what values i fill my data with, the texture is drawn black. Since it is being drawn to the screen, I use the screen coordinates as texel coordinates in the shader.
<div class="ubbcode-block"><div class="ubbcode-header">Click to reveal.. <input type="button" class="form-button" value="Show me!" onclick="toggle_spoiler(this, 'Yikes, my eyes!', 'Show me!')" />]<div style="display: none;">

static const Uint32 MAX_UINT32 = 0xFFFFFFFF;
void CreateTexture(){
	Uint32 lsize = SCREEN_WIDTH*SCREEN_HEIGHT*4;
	GLuint* ldata = new GLuint[lsize];
	for( Uint32 i=0; i<lsize; ++i ){
		if( (i+1)%4 ){
			ldata[i]=0;  //black
		}
		else{
			ldata[i]=MAX_UINT32;  //alpha
		}
	}
        //white pixel in center of screen
	ldata[lsize/2+(Uint32)HALF_W] = MAX_UINT32;
	ldata[lsize/2+(Uint32)HALF_W+1] = MAX_UINT32;
	ldata[lsize/2+(Uint32)HALF_W+2] = MAX_UINT32;
 
	glActiveTexture( GL_TEXTURE0 );
 
	glGenTextures( 1, &amp;mTexId );
	glBindTexture( GL_TEXTURE_RECTANGLE, mTexId );
	glTexImage2D(	GL_TEXTURE_RECTANGLE, 0, GL_RGBA, 
			SCREEN_WIDTH, SCREEN_HEIGHT, 0, 
			GL_RGBA, GL_UNSIGNED_INT, ldata );
	delete[] ldata;
}

[/QUOTE]</div>

No white pixels show up, even if I initialize all the data to MAX_UINT32

[mobeen]

Try this

Uint32 lsize = SCREEN_WIDTH*SCREEN_HEIGHT*4;
Uint32 HALF_W = SCREEN_WIDTH>>1;
Uint32 HALF_H = SCREEN_HEIGHT>>1;
GLuint* ldata = new GLuint[lsize];
for( Uint32 i=0; i<lsize; ++i ){
   if( (i+1)%4 ){
      ldata[i]=0;  //black
   }
   else{
      ldata[i]=MAX_UINT32;  //alpha
   }
}
  //white pixel in center of screen
  ldata[(SCREEN_WIDTH*HALF_W+ HALF_H)*4] = MAX_UINT32;
  ldata[(SCREEN_WIDTH*HALF_W+ HALF_H)*4+1] = MAX_UINT32;
  ldata[(SCREEN_WIDTH*HALF_W+ HALF_H)*4+2] = MAX_UINT32; 		
  glActiveTexture( GL_TEXTURE0 );
  glGenTextures( 1, &amp;mTexId );
  glBindTexture( GL_TEXTURE_RECTANGLE, mTexId );
  glTexParameteri(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  glTexImage2D(	GL_TEXTURE_RECTANGLE, 0, GL_RGBA, SCREEN_WIDTH, SCREEN_HEIGHT, 0, GL_RGBA, GL_UNSIGNED_INT, ldata );
  delete[] ldata;

Also make sure that the texture coordinates you assign to the geometry are not normalized like this,

glBegin(GL_QUADS);
   glTexCoord2f(0,0);glVertex2i(0,0);
   glTexCoord2f(SCREEN_WIDTH,0);glVertex2i(SCREEN_WIDTH,0);
   glTexCoord2f(SCREEN_WIDTH,SCREEN_HEIGHT);glVertex2i(SCREEN_WIDTH,SCREEN_HEIGHT);
   glTexCoord2f(0,SCREEN_HEIGHT);glVertex2i(0,SCREEN_HEIGHT);
glEnd();

[PrestoChung]

Still can't get anything but black pixels to draw. And yes, since the texel coords and screen coords co-incide, I am just passing on the texture coordinates like so [tt]out vec2 texPos = inVertex.xy[/tt]

Isn't MAX_UINT32 supposed to be white for a texture specified with
GL_UNSIGNED_INT as the type? Even if I fill my data with all MAX_UINT32 values, it still draws black.

[mobeen]

Isn't MAX_UINT32 supposed to be white for a texture specified with
GL_UNSIGNED_INT as the type? Even if I fill my data with all MAX_UINT32 values, it still draws black.

Well i get this output which is exactly what I should get.
Could u try this minimal glut code and tell me what u get?

#include <gl/glew.h>
#include <gl/glut.h> 
typedef unsigned int Uint32;
static const Uint32 SCREEN_WIDTH = 800;
static const Uint32 SCREEN_HEIGHT = 600;
static const Uint32 MAX_UINT32 = 0xFFFFFFFF;
int HALF_W = SCREEN_WIDTH>>1;
int HALF_H = SCREEN_HEIGHT>>1;
GLuint txt; 
unsigned char* bitmapData;
void Render()
{	
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); 
  glBegin(GL_QUADS);
    glTexCoord2i(0,0);glVertex2i(0,0);
    glTexCoord2i(SCREEN_WIDTH,0);glVertex2i(SCREEN_WIDTH,0);
    glTexCoord2i(SCREEN_WIDTH,SCREEN_HEIGHT);glVertex2i(SCREEN_WIDTH,SCREEN_HEIGHT);
    glTexCoord2i(0,SCREEN_HEIGHT);glVertex2i(0,SCREEN_HEIGHT);
  glEnd();
 
  glFinish();
  glutSwapBuffers();
}
void CreateTexture(GLuint* texID){
  Uint32 lsize = SCREEN_WIDTH*SCREEN_HEIGHT*4 ;
  GLuint* ldata = new GLuint[lsize ];
  memset(ldata,0,lsize );
  for( Uint32 i=0; i<lsize; ++i ){
    if( (i+1)%4 ){
	ldata[i]=0;  //black
    }else{
	ldata[i]=MAX_UINT32;  //alpha
    }
  }	
  //white pixel in center of screen
  ldata[(SCREEN_WIDTH*HALF_H+ HALF_W)*4] = MAX_UINT32;
  ldata[(SCREEN_WIDTH*HALF_H+ HALF_W)*4+1] = MAX_UINT32;
  ldata[(SCREEN_WIDTH*HALF_H+ HALF_W)*4+2] = MAX_UINT32; 
 
  glActiveTexture( GL_TEXTURE0 );
  glGenTextures( 1, texID );
  glBindTexture( GL_TEXTURE_RECTANGLE, *texID );
  glTexParameterf(GL_TEXTURE_RECTANGLE, GL_TEXTURE_MIN_FILTER, GL_NEAREST); 
  glTexImage2D(	GL_TEXTURE_RECTANGLE, 0, GL_RGBA, SCREEN_WIDTH, SCREEN_HEIGHT, 0, GL_RGBA, GL_UNSIGNED_INT, ldata );
  delete[] ldata;
}
 
 
int main(int argc, char** argv)
{	
  glutInit(&amp;argc,argv);
  glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE);
  glutInitWindowSize(SCREEN_WIDTH,SCREEN_HEIGHT);
  glutCreateWindow("SIMPLE DISPLAY");
  glewInit();
  glutDisplayFunc(Render);	
 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(0,SCREEN_WIDTH, 0, SCREEN_HEIGHT);
 
  glEnable(GL_TEXTURE_RECTANGLE);    
  CreateTexture(&amp;txt); 
  glutMainLoop();
  return 0;
}

This should give u this output. There is a small white dot in the center.

[PrestoChung]

I think it's because I'm using sampler2D but I need samplerRECT

Is this not core functionality in a 3.3 context? How hard would it be to add?

[Alfonse Reinheart]

I think it's because I'm using sampler2D but I need samplerRECT

And that's why it's a good idea to post your shader.

Is this not core functionality in a 3.3 context? How hard would it be to add?

You just use a samplerRect in your shader instead of a sampler2d.

[PrestoChung]

Okay I found that I can use a usampler2DRect,
but there does not seem to be defined a texture2DRect( , );, I get the shader compiler error C7531: "global function texture2DRect requires "#extension GL_EXT_gpu_shader4 : enable" before use

is this a line I can add to my code somewhere? or do I need some header files?

Edit: I got it, just add #extension GL_EXT_gpu_shader4 : enable to my shader now it all works

[PrestoChung]

Is GL_TEXTURE_RECTANGLE not compatible with glCopyTexImage2D? I wanted to copy the last frame into this texture but it would complicate things if the texture has to be a power of 2 instead of the screen dimensions.

[mobeen]

Is GL_TEXTURE_RECTANGLE not compatible with glCopyTexImage2D? I wanted to copy the last frame into this texture but it would complicate things if the texture has to be a power of 2 instead of the screen dimensions.

glCopyTexImage2D should work fine with GL_TEXTURE_RECTANGLE. You should check your code. The first thing i would look at is my texture format and the internal format I am passing to glCopyTexImage2D.

[PrestoChung]

<div class="ubbcode-block"><div class="ubbcode-header">Click to reveal.. <input type="button" class="form-button" value="Show me!" onclick="toggle_spoiler(this, 'Yikes, my eyes!', 'Show me!')" />]<div style="display: none;">

#version 330
#extension GL_EXT_gpu_shader4 : enable
 
uniform usampler2DRect tex;
 
in vec2 texPos;
 
out vec4 outFragColor;
 
void main()
{
	vec4 out_color;
	vec4 tex_color_left;
 
	vec2 top = vec2(0, 1);
	vec2 bottom = vec2(0, -1);
	vec2 right = vec2(1, 0);
	vec2 left = vec2(-1, 0);
 
	tex_color_left = texture(tex, texPos+left);
 
	if( tex_color_left.x>0.5 ){
		out_color = vec4(1.0, 1.0, 1.0, 1.0);
	}
	else{
		out_color = vec4(0.0, 0.0, 0.0, 1.0);
	}
 
	outFragColor = out_color;
}

[/QUOTE]</div>

Edit: ah, i answered my own question again (problem with equality with floats)