Trying to load RAW file textures please help (c and openGL)

This is a discussion on Trying to load RAW file textures please help (c and openGL) within the C Programming forums, part of the General Programming Boards category; Hiya Im writing a program in C using openGL (GLUT) and im having a little trouble with the function to ...

  1. #1
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    Trying to load RAW file textures please help (c and openGL)

    Hiya
    Im writing a program in C using openGL (GLUT) and im having a little trouble with the function to process textures (RAW files). It compiles ok but when i bind the texture in my display function and apply it to a quad it does not display it at runtime (just has a simple RGB default colour i had assigned with glColor3f). It has to be because its not allocating the memory correctly with the malloc i think? but i cant think of a way to just get it working, can anyone please maybe help me.. Pretty please? Im getting really frustrated lol.

    Below is the texture processing function:

    Code:
    // load a 256x256 RGB .RAW file as a texture
    GLuint LoadTextureRAW( const char * filename, int wrap ) {
    
      GLuint texture;
      int width, height;
      BYTE * data;
      FILE * file;
    
      // open texture data
      file = fopen( filename, "rb" );
      if ( file == NULL ) return 0;
    
      // allocate buffer
      width	 = 256;
      height = 256;
      data = (BYTE*)malloc( width * height * 3 );  // <---- is this right?
    
      // read texture data
      fread( data, width * height * 3, 1, file );
      fclose( file );
    
      // allocate a texture name
      glGenTextures( 1, &texture );
    
      // select our current texture
      glBindTexture( GL_TEXTURE_2D, texture );
    
      // select modulate to mix texture with color for shading
      glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
    
      // when texture area is small, bilinear filter the closest MIP map
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST );
      // when texture area is large, bilinear filter the first MIP map
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    
      // if wrap is true, the texture wraps over at the edges (repeat)
      //       ... false, the texture ends at the edges (clamp)
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrap ? GL_REPEAT : GL_CLAMP );
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrap ? GL_REPEAT : GL_CLAMP );
    
      // build our texture MIP maps
      gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height, GL_RGB, GL_UNSIGNED_BYTE, data );
    
      // free buffer
      free( data );
    
      return texture;
    }
    Im using it like this (just showing the parts that matter):

    Code:
    GLuint texture;
    texture = LoadTextureRAW("bush.raw", TRUE);
    
    glBindTexture(GL_TEXTURE_2D, texture);
    
    glBegin(GL_QUADS);				
    	glColor3f(0.0, 0.6, 0.0); //Just the default colour
    	glTexCoord2f(0.0,0.0);
    	glVertex3f(-1000.0, 0.0, 1000.0);
    	glTexCoord2f(0.0,1.0);
    	glVertex3f(1000.0, 0.0, 1000.0);
    	glTexCoord2f(1.0,1.0); 
    	glVertex3f(1000.0, 0.0, -1000.0);
    	glTexCoord2f(1.0,0.0); 
    	glVertex3f(-1000.0, 0.0, -1000.0);		
    glEnd();
    I really need to get this working

    Thanks.

  2. #2
    Frequently Quite Prolix dwks's Avatar
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    Code:
    data = (BYTE*)malloc( width * height * 3 );  // <---- is this right?
    Other than the cast, probably, assuming sizeof(BYTE) == 1.
    dwk

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  3. #3
    vae victus! skorman00's Avatar
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    Just because you bound a texture doesn't mean it's glEnable()'ed.

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