CODEWITHSUNDEEP
opengllwjgllighting
Luis Cruz
Luis Cruz

Reputation: 187

Fast way to make vertices darker?

To make a lighting system for a voxel game, I need to specify a darkness value per vertex. I'm using GL_COLOR_MATERIAL and specifying a color per vertex, like this:

glEnable(GL_COLOR_MATERIAL);

glBegin(GL_QUADS);

glColor3f(0.6f, 0.6f, 0.6f);
glTexCoord2f(...);
glVertex3f(...);

glColor3f(0.3f, 0.3f, 0.3f);    
glTexCoord2f(...);
glVertex3f(...);

glColor3f(0.7f, 0.7f, 0.7f);        
glTexCoord2f(...);
glVertex3f(...);

glColor3f(0.9f, 0.9f, 0.9f);
glTexCoord2f(...);
glVertex3f(...);

glEnd();

This is working, but with many quads it is very slow. I'm using display lists too. Any good ideas in how to make vertices darker?

Upvotes: 0

Views: 148

Answers (1)

datenwolf
datenwolf

Reputation: 162164

You're using immediate mode (glBegin, glEnd and everything in between). If performance is what you need, then I recommend you stop doing that.

What you're probably after is a generic vertex attribute. And lo and behold: Modern OpenGL actually has exactly this: Generic attributes. They even went so far, doing the right thing and do away with the predefined attributes (position, color, normal, texcoords, etc.) and have only generic attributes in OpenGL-3 core and later.

The functions glVertexAttrib (most of the time a Uniform does the job better) and glVertexAttribPointer are your friends. Specify how vertex attributes are processed using an appropriate vertex shader.

Upvotes: 1

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