GLTEXTUREENV

GLTEXTUREENV is a constant used in OpenGL programming to specify the texture environment. Texture environments define how a texture's color is combined with the fragment's existing color. When using the GL_TEXTURE_ENV mode, subsequent fragment operations will use the texture color in a defined manner. There are several modes for GL_TEXTURE_ENV, including GL_REPLACE, GL_MODULATE, and GL_DECAL. GL_REPLACE replaces the fragment's color with the texture color. GL_MODULATE multiplies the texture color with the fragment's color. GL_DECAL applies the texture color to the fragment color. The specific behavior depends on the combination of the GL_TEXTURE_ENV_MODE and potentially other parameters like GL_TEXTURE_ENV_COLOR. This allows developers to control how textures are applied to surfaces in a 3D scene. It's a fundamental part of OpenGL's texturing pipeline, enabling various visual effects from simple color mapping to more complex blending.