mozilla-bmo849632.patch
author Wolfgang Rosenauer <wr@rosenauer.org>
Tue, 25 Aug 2020 21:27:22 +0200
branchfirefox80
changeset 1141 edb0ebe8cccc
parent 1123 7fa561e5d7c7
permissions -rw-r--r--
Firefox 80.0

# HG changeset patch
# Parent  3de59fe1b8708c01e134ce698c4232b8a854f617
Problem:  webGL sites are displayed in the wrong color (usually blue-ish)
Solution: Problem is with skia once again. Output of webgl seems endian-correct, but skia only
          knows how to deal with little endian.
          So we swizzle the output of webgl after reading it from readpixels()
Note:     This does not fix all webGL sites, but is a step in the right direction

diff --git a/gfx/gl/GLContext.h b/gfx/gl/GLContext.h
--- a/gfx/gl/GLContext.h
+++ b/gfx/gl/GLContext.h
@@ -1548,16 +1548,23 @@ class GLContext : public GenericAtomicRe
     AFTER_GL_CALL;
   }
 
   void raw_fReadPixels(GLint x, GLint y, GLsizei width, GLsizei height,
                        GLenum format, GLenum type, GLvoid* pixels) {
     BEFORE_GL_CALL;
     mSymbols.fReadPixels(x, y, width, height, format, type, pixels);
     OnSyncCall();
+#if MOZ_BIG_ENDIAN()
+    uint8_t* itr = (uint8_t*)pixels;
+    for (GLsizei i = 0; i < width * height; i++) {
+      NativeEndian::swapToLittleEndianInPlace((uint32_t*)itr, 1);
+      itr += 4;
+    }
+#endif
     AFTER_GL_CALL;
     mHeavyGLCallsSinceLastFlush = true;
   }
 
   void fReadPixels(GLint x, GLint y, GLsizei width, GLsizei height,
                    GLenum format, GLenum type, GLvoid* pixels);
 
  public: