Commit e755774407d24be85d764b5f871fe05a699eea42
2017-06-01T13:09:57
WebGL compatibility: remove UB for draw buffers in the GL backend. WebGL adds two rules: - Fragment outputs declared but not written to should default to black. - FBO attachments for outputs not declared in the shader should not be written to (it is UB in OpenGL ES). Fix the first one by using the SH_INIT_OUTPUT_VARIABLES compiler options, and the second one by messing with glDrawBuffers so that the enabled draw buffers are always a subset of the ones declared by the shader. BUG=angleproject:2048 Change-Id: I1d851c190959c1acfc3e41d837e6990aec1d4086 Reviewed-on: https://chromium-review.googlesource.com/521682 Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>