| Summary: | [i915 GLSL gles2] gl_FragCoord.w not correct | ||
|---|---|---|---|
| Product: | Mesa | Reporter: | Shuang He <shuang.he> |
| Component: | Drivers/DRI/i915 | Assignee: | Kenneth Graunke <kenneth> |
| Status: | VERIFIED FIXED | QA Contact: | |
| Severity: | normal | ||
| Priority: | medium | ||
| Version: | unspecified | ||
| Hardware: | Other | ||
| OS: | All | ||
| Whiteboard: | |||
| i915 platform: | i915 features: | ||
| Attachments: | piglit OpenGL GLSL case, this case fail on pineview and pass on ironlake | ||
commit fceda4342cadc22ce86877a19bf82b86eb022d79 Author: Eric Anholt <eric@anholt.net> Date: Wed Jul 13 10:56:37 2011 -0700 i915: Include gl_FragCoord.w data, not just xyz. Fixes piglit fragcoord_w test. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34323 Since related OpenGL ES 2.0 conformance case passed on both ironlake and pineview, I will mark this bug as verified against mesa: (7.11)436db5df9c193b4849afd37ce7e1697274ca25d8 (master)4abba27ae06b21111adfa1c0446b38d57b61e947 |
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Created attachment 43418 [details] piglit OpenGL GLSL case, this case fail on pineview and pass on ironlake System Environment: -------------------------- Libdrm: (master)2.4.23-6-g550fe2ca3b29ad2191eab4fdfbed9ed21e25492d Mesa: (master)6ed0f2ac112d22278cf051c2cee9c2199a9025ea Xserver: (master)xorg-server-1.9.99.901-197-gea1ffd3e60bdcedbec5a6f28929f8677bf45d450 Xf86_video_intel: (master)2.14.0-25-g9184af921bc2f332fcb6c9b47001414378eab8e2 Bug detailed description: ------------------------- This bug hapens on Pineview. This issue happens to both OpenGL GLSL and OpenGL ES 2.0 GLSL According to OpenGL ES specificaton, section 3.8.2: "The built-in variable gl_FragCoord holds the window coordinates x, y, z, and 1/w for the fragment. The z component of gl_FragCoord undergoes an implied conversion to floating-point. This conversion must leave the values 0 and 1 invariant. Note that this z component already has a polygon offset added in, if enabled (see section 3.5.2. The 1/w value is computed from the wc coordinate (see section 2.12)." Following OpenGL GLSL case could be used to reproduce the issue: [require] GLSL >= 1.10 [vertex shader] void main() { gl_Position = gl_Vertex; gl_Position.w = 2.0; } [fragment shader] void main() { gl_FragColor = vec4(1.0, gl_FragCoord.w, 1.0, 0.0); } [test] draw rect -1 -1 2 2 relative probe rgb (0.5, 0.5) (1.0, 0.5, 1.0)