COMBINE_EXT

OpenGL OpenGL: Advanced Coding
1

Where can i find nice samples of the new texture environment functions which allows
GL_COMBINE_EXT… I’ve wrapped the opengl dll thus all extension are loaded but…

Something is missing in my lazy brain!

any help would be cool… i’am interested to manage new functionalities like ADD,SUB,MODULATE and x2,x4 scale factors…

thanks.

2

here is an answer for simple environments:

void vrCombineFunc(VR_TEXTURE_UNITS unit,VR_COMBINING combine)
{
glActiveTextureARB(unit+GL_TEXTURE0_ARB);
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_EXT);

glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB_EXT, combiningStates[combine]);
glTexEnvi(GL_TEXTURE_ENV, GL_SOURCE0_RGB_EXT, GL_TEXTURE);
glTexEnvi(GL_TEXTURE_ENV, GL_OPERAND0_RGB_EXT, GL_SRC_COLOR);

switch(combine){
	case VR_COMBINE_MODULATE2X:
		glTexEnvf(GL_TEXTURE_ENV,GL_RGB_SCALE_EXT,2.f);
		break;
	case VR_COMBINE_MODULATE4X:
		glTexEnvf(GL_TEXTURE_ENV,GL_RGB_SCALE_EXT,4.f);
		break;
	default:
		glTexEnvf(GL_TEXTURE_ENV,GL_RGB_SCALE_EXT,1.f);
}