Use SkMatrix44 for the underlying implementation of ui::Transform

ui/gfx/compositor/compositor_gl.cc

Index: ui/gfx/compositor/compositor_gl.cc
diff --git a/ui/gfx/compositor/compositor_gl.cc b/ui/gfx/compositor/compositor_gl.cc
index e591e2accf084ca4dc043c7eed8b0f6b53165469..137d9e203578ed783fcb76f5aa829c8187fd3f19 100644
--- a/ui/gfx/compositor/compositor_gl.cc
+++ b/ui/gfx/compositor/compositor_gl.cc
@@ -161,31 +161,14 @@ void TextureGL::Draw(const ui::Transform& transform) {
   glUniform1i(compositor_->u_tex_loc(), 0);
   glBindTexture(GL_TEXTURE_2D, texture_id_);
 
+  const SkMatrix44& matrix = t.matrix();

[rjkroege, 2011/06/10 17:52:14]

Given Ganesh, there should be a single call into SKMatrix44 that returs an array
pointer that you can pass to glUniformMatrix4fv. 

+
   GLfloat m[16];
-  const SkMatrix& matrix = t.matrix();
-
-  // Convert 3x3 view transform matrix (row major) into 4x4 GL matrix (column
-  // major). Assume 2-D rotations/translations restricted to XY plane.
-
-  m[ 0] = matrix[0];
-  m[ 1] = matrix[3];
-  m[ 2] = 0;
-  m[ 3] = matrix[6];
-
-  m[ 4] = matrix[1];
-  m[ 5] = matrix[4];
-  m[ 6] = 0;
-  m[ 7] = matrix[7];
-
-  m[ 8] = 0;
-  m[ 9] = 0;
-  m[10] = 1;
-  m[11] = 0;
-
-  m[12] = matrix[2];
-  m[13] = matrix[5];
-  m[14] = 0;
-  m[15] = matrix[8];
+  for (int i = 0; i < 4; ++i) {
+    for (int j = 0; j < 4; ++j) {
+      m[i + j * 4] = matrix.get(i, j);
+    }
+  }
 
   const GLfloat vertices[] = { -1., -1., +0., +0., +1.,
                                +1., -1., +0., +1., +1.,