HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 155

F glFog glFog glFogf, glFogi, glFogfv, glFogiv: specify fog parameters. C Specification void glFogf( GLenum pname, GLfloat param) void glFogi( GLenum pname, GLint param) void glFogfv( GLenum pname, const GLfloat *params) void glFogiv( GLenum pname, const GLint *params) Parameters pname param pname params Specifies a single-valued fog parameter. GL_FOG_MODE, GL_FOG_DENSITY, GL_FOG_START, GL_FOG_END, and GL_FOG_INDEX are accepted. Specifies the value that pname will be set to. Specifies a fog parameter. GL_FOG_MODE, GL_FOG_DENSITY, GL_FOG_START, GL_FOG_END, GL_FOG_INDEX, and GL_FOG_COLOR are accepted. Specifies the value or values to be assigned to pname. GL_FOG_COLOR requires an array of four values. All other parameters accept an array containing only a single value. Description Fog is initially disabled. While enabled, fog affects rasterized geometry, bitmaps, and pixel blocks, but not buffer clear operations. To enable and disable fog, call glEnable and glDisable with argument GL_FOG. glFog assigns the value or values in params to the fog parameter specified by pname. The following values are accepted for pname: GL_FOG_MODE params is a single integer or floating-point value that specifies the equation to be used to compute the fog blend factor, f. Three symbolic constants are accepted: GL_LINEAR, GL_EXP, and GL_EXP2. The equations corresponding to these symbolic constants are defined below. The initial fog mode is GL_EXP. GL_FOG_DENSITY Chapter 6 155