OpenGL (desktop and ES) have the following expectations of gl_VertexID: 1. When used with BaseVertex drawing commands, gl_VertexID will include the value of basevertex. This differens from "the other API," but the change in OpenGL was based on feedback from application developers. This only affects OpenGL 3.2+.
2. When used with DrawArrays drawing commands, gl_VertexID will count from the 'start' value instead of zero. This affects OpenGL 3.0+ and OpenGL ES 3.0+. At the very least, the i965 driver in Mesa doesn't implement either of these behaviors. These tests are almost identical. The main differences: gl-3.2: Uses glMultiDrawElementsBaseVertex and creates an index array. gles-3.0: Uses glDrawArrays in a loop. gl-3.0: Uses glMultiDrawArrays. GLES does not have glMultiDrawArrays, and using a different function here gives slightly more test coverage. I didn't see an obvious way to share code by all three without build gymnastics. The gl-3.0 and gles-3.0 tests could be made to share code without too much effort. I'm looking for opinions or suggestions. _______________________________________________ Piglit mailing list Piglit@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/piglit