Always apply UniformMatrix4fvStreamTextureMatrixCHROMIUM matrix argument.

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 7599 matching lines @@
                                    &type,
                                    &count)) {
     return;
   }
   glUniformMatrix4fv(real_location, count, transpose, value);
 }
 
 void GLES2DecoderImpl::DoUniformMatrix4fvStreamTextureMatrixCHROMIUM(
     GLint fake_location,
     GLboolean transpose,
-    const GLfloat* default_value) {
+    const GLfloat* transform) {
   float gl_matrix[16];
 
-  // If we can't get a matrix from the texture, then use a default.
-  // TODO(liberato): remove |default_value| and replace with an identity matrix.
-  // It is only present as a transitionary step until StreamTexture supplies
-  // the matrix via GLImage.  Once that happens, GLRenderer can quit sending
-  // in a default.
-  memcpy(gl_matrix, default_value, sizeof(gl_matrix));
-
   // This refers to the bound external texture on the active unit.
   TextureUnit& unit = state_.texture_units[state_.active_texture_unit];
   if (TextureRef* texture_ref = unit.bound_texture_external_oes.get()) {
     if (GLStreamTextureImage* image =
             texture_ref->texture()->GetLevelStreamTextureImage(
                 GL_TEXTURE_EXTERNAL_OES, 0)) {
       image->GetTextureMatrix(gl_matrix);
+      GLfloat tmp[16];
+      for (int c = 0; c < 16; c += 4) {
+        for (int r = 0; r < 4; ++r) {

[no sievers, 2016/04/01 21:39:53]

Can you use gfx::Transform for the multiplication?

[no sievers, 2016/04/11 18:08:50]

^^ what about this?

[Tobias Sargeant, 2016/04/12 11:05:24]

I've reimplemented with gfx::Transform. WDYT?

+          tmp[c + r] = 0.0f;
+          for (int i = 0; i < 4; ++i) {
+            tmp[c + r] += gl_matrix[r + 4 * i] * transform[c + i];
+          }
+        }
+      }
+      std::copy(tmp, tmp + 16, gl_matrix);
+    } else {
+      // Missing stream texture. Treat matrix as identity.
+      memcpy(gl_matrix, transform, sizeof(gl_matrix));
     }
   } else {
     LOCAL_SET_GL_ERROR(GL_INVALID_OPERATION,
                        "DoUniformMatrix4vStreamTextureMatrix",
                        "no texture bound");
     return;
   }
 
   GLenum type = 0;
   GLint real_location = -1;
@@ skipping 6263 matching lines @@
   }
 
   DoCopyTexImageIfNeeded(source_texture, source_target);
 
   // GL_TEXTURE_EXTERNAL_OES texture requires that we apply a transform matrix
   // before presenting.
   if (source_target == GL_TEXTURE_EXTERNAL_OES) {
     if (GLStreamTextureImage* image =
             source_texture->GetLevelStreamTextureImage(GL_TEXTURE_EXTERNAL_OES,
                                                        0)) {
-      // The coordinate system of this matrix is y-up, not y-down, so a flip is
-      // needed.
       GLfloat transform_matrix[16];
-      image->GetFlippedTextureMatrix(transform_matrix);
+      image->GetTextureMatrix(transform_matrix);
       copy_texture_CHROMIUM_->DoCopyTextureWithTransform(
           this, source_target, source_texture->service_id(), dest_target,
           dest_texture->service_id(), source_width, source_height,
           unpack_flip_y == GL_TRUE, unpack_premultiply_alpha == GL_TRUE,
           unpack_unmultiply_alpha == GL_TRUE, transform_matrix);
       return;
     }
   }
   copy_texture_CHROMIUM_->DoCopyTexture(
       this, source_target, source_texture->service_id(), source_internal_format,
@@ skipping 170 matching lines @@
 
   DoCopyTexImageIfNeeded(source_texture, source_target);
 
 
   // GL_TEXTURE_EXTERNAL_OES texture requires apply a transform matrix
   // before presenting.
   if (source_target == GL_TEXTURE_EXTERNAL_OES) {
     if (GLStreamTextureImage* image =
             source_texture->GetLevelStreamTextureImage(GL_TEXTURE_EXTERNAL_OES,
                                                        0)) {
-      // The coordinate system of this matrix is y-up, not y-down, so a flip is
-      // needed.
       GLfloat transform_matrix[16];
-      image->GetFlippedTextureMatrix(transform_matrix);
+      image->GetTextureMatrix(transform_matrix);
       copy_texture_CHROMIUM_->DoCopySubTextureWithTransform(
           this, source_target, source_texture->service_id(),
           source_internal_format, dest_target, dest_texture->service_id(),
           dest_internal_format, xoffset, yoffset, x, y, width, height,
           dest_width, dest_height, source_width, source_height,
           unpack_flip_y == GL_TRUE, unpack_premultiply_alpha == GL_TRUE,
           unpack_unmultiply_alpha == GL_TRUE, transform_matrix);
       return;
     }
   }
@@ skipping 2249 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu