Commits (1)
  • chadversary's avatar
    getteximage-formats: Disable dithering during glDrawPixels · bb05b88c
    chadversary authored
    The test generates a mipmap by "copying" a client-array of pixels to
    miplevel 0 with glDrawPixels, then calling glGenerateMipmap. The test
    expects the rendered level 0 to match the client-array source. Dithering
    during glDrawPixels inteferes with that expectation.
    Fixes on Intel Skylake:
      spec.ext_framebuffer_object.getteximage-formats init-by-clear-and-render
      spec.ext_framebuffer_object.getteximage-formats init-by-render
    Regressed by Mesa:
      commit c4b87f129eb036c9615df3adcc1cebd9df10fc84
      Author: Chad Versace <chadversary@chromium.org>
      Subject: meta: Disable dithering during glGenerateMipmap
    Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99266
    Cc: Mark Janes <mark.a.janes@intel.com>
    Cc: Kenneth Graunke <kenneth@whitecape.org>
......@@ -110,8 +110,33 @@ make_texture_image(GLenum intFormat, GLubyte upperRightTexel[4])
glViewport(0, 0, TEX_SIZE, TEX_SIZE);
/* Disable dithering during glDrawPixels to prevent
* disagreement with glGenerateMipmap. The spec requires
* glDrawPixels to respect the dither state, but the spec
* strongly implies that glGenerateMipmap should not dither.
* On dithering and glDrawPixels, see the OpenGL 4.5
* Compatibility Specification, Section 18.1 Drawing Pixels,
* p620:
* Once pixels are transferred, DrawPixels performs final
* conversion on pixel values [...] which are processed in
* the same fashion as fragments generated by rasterization
* (see chapters 15 and 16).
* On dithering and glGenerateMipmap, see the Mesa commit
* message in:
* commit c4b87f129eb036c9615df3adcc1cebd9df10fc84
* Author: Chad Versace <chadversary@chromium.org>
* Date: Thu Dec 29 13:05:27 2016 -0800
* Subject: meta: Disable dithering during glGenerateMipmap
glWindowPos2iARB(0, 0);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, piglit_winsys_fbo);