HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 446
Gl_luminance, Gl_luminance_alpha, Gl_rgb, And Gl_rgba Must
View all HP Workstation zx2000 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 446 highlights
T glTexImage3DEXT color components using the GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A tables, and clamped to the range [0, 1]. GL_RED Each element is a single red component. It is converted to floating-point and assembled into an RGBA element by attaching 0.0 for green and blue, and 1.0 for alpha. GL_GREEN Each element is a single green component. It is converted to floating-point and assembled into an RGBA element by attaching 0.0 for red and blue, and 1.0 for alpha. GL_BLUE Each element is a single blue component. It is converted to floating-point and assembled into an RGBA element by attaching 0.0 for red and green, and 1.0 for alpha. GL_ALPHA Each element is a single alpha component. It is converted to floating-point and assembled into an RGBA element by attaching 0.0 for red, green, and blue. GL_RGB Each element is an RGB triple. It is converted to floating-point and assembled into an RGBA element by attaching 1.0 for alpha (see glPixelTransfer). GL_RGBA, GL_ABGR_EXT Each element contains all four components; for GL_RGBA, the red component is first, followed by green, then blue, and then alpha; for GL_ABGR_EXT the order is alpha, blue, green, and then red. GL_LUMINANCE Each element is a single luminance value. It is converted to floating-point, then assembled into an RGBA element by replicating the luminance value three times for red, green, and blue and attaching 1.0 for alpha. GL_LUMINANCE_ALPHA Each element is a luminance/alpha pair. It is converted to floating-point, then assembled into an RGBA element by replicating the luminance value three times for red, green, and blue. Please refer to the glDrawPixels reference page for a description of the acceptable values for the type parameter. An application may desire that the texture be stored at a certain resolution, or that it be stored in a certain format. This resolution and format can be requested by internalformat, but the implementation may not support that resolution (the formats of GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, and GL_RGBA must be supported). When a resolution and storage format is specified, the implementation will update the texture state to provide the best match to the requested resolution. The GL_PROXY_TEXTURE_3D_EXT target can be used to try a resolution and format. The implementation will compute its best match for the requested storage resolution and format; this state can then be queried using glGetTexLevelParameter. 446 Chapter 18