Context & stateGL 1.0
glClearColor
Chooses the color glClear will fill the color buffer with.
Signature
void glClearColor(GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
How it works
This only stores a color in the context state — it does not clear anything by itself. The next glClear(GL_COLOR_BUFFER_BIT) uses it. Since it is state, you can set it once at startup.
Parameters
redGLfloat
Red, 0.0 to 1.0.
greenGLfloat
Green, 0.0 to 1.0.
blueGLfloat
Blue, 0.0 to 1.0.
alphaGLfloat
Alpha, usually 1.0.
Tips & pitfalls
Values are floats between 0 and 1, not 0–255. Divide by 255 if you copy a color from a picker.
Example
example.cpp
1glClearColor(0.1f, 0.1f, 0.12f, 1.0f); // dark grey
2// every frame:
3glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);