Cache OpenGL textures and other objects in CompositingIOSurfaceMac copy/transform code.

content/browser/renderer_host/compositing_iosurface_transformer_mac.cc

Index: content/browser/renderer_host/compositing_iosurface_transformer_mac.cc
diff --git a/content/browser/renderer_host/compositing_iosurface_transformer_mac.cc b/content/browser/renderer_host/compositing_iosurface_transformer_mac.cc
index da2ba6aec2b5aa8911cad2e60b6e8257961ba3d5..28090d4804b5da2dddc7cefaf22ba9c82b64a9ba 100644
--- a/content/browser/renderer_host/compositing_iosurface_transformer_mac.cc
+++ b/content/browser/renderer_host/compositing_iosurface_transformer_mac.cc
@@ -17,68 +17,11 @@ namespace content {
 
 namespace {
 
-// Simple auto-delete scoping support for an owned Framebuffer object.
-class ScopedFramebuffer {
- public:
-  ScopedFramebuffer() {
-    glGenFramebuffersEXT(1, &name_);
-  }
-
-  ~ScopedFramebuffer() {
-    if (name_ != 0u)
-      glDeleteFramebuffersEXT(1, &name_);
-  }
-
-  bool is_valid() const { return name_ != 0u; }
-  GLuint name() const { return name_; }
-
- private:
-  GLuint name_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedFramebuffer);
+const GLenum kColorAttachments[] = {
+  GL_COLOR_ATTACHMENT0_EXT,
+  GL_COLOR_ATTACHMENT1_EXT
 };
 
-// Simple auto-delete scoping support for an owned texture object.
-class ScopedTexture {
- public:
-  ScopedTexture() : name_(0u) {}
-  ScopedTexture(GLenum target, const gfx::Size& size);
-
-  ~ScopedTexture() {
-    if (name_ != 0u)
-      glDeleteTextures(1, &name_);
-  }
-
-  bool is_valid() const { return name_ != 0u; }
-  GLuint name() const { return name_; }
-
-  void Reset(GLuint texture) {
-    if (name_ != 0u)
-      glDeleteTextures(1, &name_);
-    name_ = texture;
-  }
-
-  GLuint Release() {
-    GLuint ret = name_;
-    name_ = 0u;
-    return ret;
-  }
-
- private:
-  GLuint name_;
-
-  DISALLOW_COPY_AND_ASSIGN(ScopedTexture);
-};
-
-ScopedTexture::ScopedTexture(GLenum target, const gfx::Size& size) {
-  glGenTextures(1, &name_);
-  glBindTexture(target, name_);
-  glTexImage2D(target, 0, GL_RGBA, size.width(), size.height(), 0, GL_BGRA,
-               GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
-  DCHECK(glGetError() == GL_NO_ERROR);
-  glBindTexture(target, 0u);
-}
-
 // Set viewport and model/projection matrices for drawing to a framebuffer of
 // size dst_size, with coordinates starting at (0, 0).
 void SetTransformationsForOffScreenRendering(const gfx::Size& dst_size) {
@@ -146,11 +89,14 @@ CompositingIOSurfaceTransformer::CompositingIOSurfaceTransformer(
     CompositingIOSurfaceShaderPrograms* shader_program_cache)
     : texture_target_(texture_target),
       src_texture_needs_y_flip_(src_texture_needs_y_flip),
-      shader_program_cache_(shader_program_cache) {
+      shader_program_cache_(shader_program_cache),
+      frame_buffer_(0) {
   DCHECK(texture_target_ == GL_TEXTURE_RECTANGLE_ARB)
       << "Fragment shaders currently only support RECTANGLE textures.";
   DCHECK(shader_program_cache_);
 
+  memset(textures_, 0, sizeof(textures_));
+
   // The RGB-to-YV12 transform requires that the driver/hardware supports
   // multiple draw buffers.
   GLint max_draw_buffers = 1;
@@ -159,6 +105,23 @@ CompositingIOSurfaceTransformer::CompositingIOSurfaceTransformer(
 }
 
 CompositingIOSurfaceTransformer::~CompositingIOSurfaceTransformer() {
+  for (int i = 0; i < NUM_CACHED_TEXTURES; ++i)
+    DCHECK_EQ(textures_[i], 0u) << "Failed to call ReleaseCachedGLObjects().";
+  DCHECK_EQ(frame_buffer_, 0u) << "Failed to call ReleaseCachedGLObjects().";
+}
+
+void CompositingIOSurfaceTransformer::ReleaseCachedGLObjects() {
+  for (int i = 0; i < NUM_CACHED_TEXTURES; ++i) {
+    if (textures_[i]) {
+      glDeleteTextures(1, &textures_[i]);
+      textures_[i] = 0;
+      texture_sizes_[i] = gfx::Size();
+    }
+  }
+  if (frame_buffer_) {
+    glDeleteFramebuffersEXT(1, &frame_buffer_);
+    frame_buffer_ = 0;
+  }
 }
 
 bool CompositingIOSurfaceTransformer::ResizeBilinear(
@@ -171,16 +134,14 @@ bool CompositingIOSurfaceTransformer::ResizeBilinear(
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_BLEND);
 
-  ScopedTexture dst_texture(texture_target_, dst_size);
-  if (!dst_texture.is_valid())
-    return false;
-
-  ScopedFramebuffer temp_frame_buffer;
-  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, temp_frame_buffer.name());
+  PrepareTexture(RGBA_OUTPUT, dst_size);
+  PrepareFramebuffer();
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, frame_buffer_);
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
-                            texture_target_, dst_texture.name(), 0);
+                            texture_target_, textures_[RGBA_OUTPUT], 0);
   DCHECK(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) ==
              GL_FRAMEBUFFER_COMPLETE_EXT);
+  glDrawBuffers(1, kColorAttachments);

[ncarter (slow), 2013/04/15 23:38:19]

This seems unnecessary.

[miu, 2013/04/16 03:51:22]

It probably is.  I was just playing it safe.  Done.

 
   glBindTexture(texture_target_, src_texture);
   SetTextureParameters(
@@ -195,9 +156,11 @@ bool CompositingIOSurfaceTransformer::ResizeBilinear(
            src_texture_needs_y_flip_,
            dst_size.width(), dst_size.height());
   glUseProgram(0);
-  glBindTexture(texture_target_, 0u);
 
-  *texture = dst_texture.Release();
+  glBindTexture(texture_target_, 0);
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+  *texture = textures_[RGBA_OUTPUT];
   return true;
 }
 
@@ -221,7 +184,7 @@ bool CompositingIOSurfaceTransformer::TransformRGBToYV12(
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_BLEND);
 
-  // Allocate output textures for each plane, and the temporary one for the UUVV
+  // Resize output textures for each plane, and for the intermediate UUVV one
   // that becomes an input into pass #2.  |packed_y_size| is the size of the Y
   // output texture, where its width is 1/4 the number of Y pixels because 4 Y
   // pixels are packed into a single quad.  |packed_uv_size| is half the size of
@@ -229,36 +192,22 @@ bool CompositingIOSurfaceTransformer::TransformRGBToYV12(
   *packed_y_size = gfx::Size((dst_size.width() + 3) / 4, dst_size.height());
   *packed_uv_size = gfx::Size((packed_y_size->width() + 1) / 2,
                               (packed_y_size->height() + 1) / 2);
-  ScopedTexture temp_texture_y(texture_target_, *packed_y_size);
-  if (!temp_texture_y.is_valid())
-    return false;
-  ScopedTexture temp_texture_u(texture_target_, *packed_uv_size);
-  if (!temp_texture_u.is_valid())
-    return false;
-  ScopedTexture temp_texture_v(texture_target_, *packed_uv_size);
-  if (!temp_texture_v.is_valid())
-    return false;
-
-  // Create a temporary texture for the UUVV that becomes an input into pass #2.
-  ScopedTexture temp_texture_uuvv(texture_target_, *packed_y_size);
-  if (!temp_texture_uuvv.is_valid())
-    return false;
-
-  // Create a temporary FBO for writing to the textures off-screen.
-  ScopedFramebuffer temp_frame_buffer;
-  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, temp_frame_buffer.name());
+  PrepareTexture(Y_PLANE_OUTPUT, *packed_y_size);
+  PrepareTexture(UUVV_INTERMEDIATE, *packed_y_size);
+  PrepareTexture(U_PLANE_OUTPUT, *packed_uv_size);
+  PrepareTexture(V_PLANE_OUTPUT, *packed_uv_size);
 
   /////////////////////////////////////////
   // Pass 1: RGB --(scaled)--> YYYY + UUVV
+  PrepareFramebuffer();
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, frame_buffer_);
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
-                            texture_target_, temp_texture_y.name(), 0);
+                            texture_target_, textures_[Y_PLANE_OUTPUT], 0);
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT,
-                            texture_target_, temp_texture_uuvv.name(), 0);
+                            texture_target_, textures_[UUVV_INTERMEDIATE], 0);
   DCHECK(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) ==
              GL_FRAMEBUFFER_COMPLETE_EXT);
-  static const GLenum kAttachments[] =
-      { GL_COLOR_ATTACHMENT0_EXT, GL_COLOR_ATTACHMENT1_EXT };
-  glDrawBuffers(2, kAttachments);
+  glDrawBuffers(2, kColorAttachments);
 
   // Read from |src_texture|.  Enable bilinear filtering only if scaling is
   // required.  The filtering will take place entirely in the first pass.
@@ -283,15 +232,15 @@ bool CompositingIOSurfaceTransformer::TransformRGBToYV12(
   /////////////////////////////////////////
   // Pass 2: UUVV -> UUUU + VVVV
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
-                            texture_target_, temp_texture_u.name(), 0);
+                            texture_target_, textures_[U_PLANE_OUTPUT], 0);
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT,
-                            texture_target_, temp_texture_v.name(), 0);
+                            texture_target_, textures_[V_PLANE_OUTPUT], 0);
   DCHECK(glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) ==
              GL_FRAMEBUFFER_COMPLETE_EXT);
 
-  // Read from texture_uuvv.  The second pass uses bilinear minification to
-  // achieve vertical scaling, so enable it always.
-  glBindTexture(texture_target_, temp_texture_uuvv.name());
+  // Read from the intermediate UUVV texture.  The second pass uses bilinear
+  // minification to achieve vertical scaling, so enable it always.
+  glBindTexture(texture_target_, textures_[UUVV_INTERMEDIATE]);
   SetTextureParameters(texture_target_, GL_LINEAR, GL_CLAMP_TO_EDGE);
 
   // Use the second-pass shader program and draw the scene.
@@ -305,15 +254,46 @@ bool CompositingIOSurfaceTransformer::TransformRGBToYV12(
            false,
            packed_uv_size->width(), packed_uv_size->height());
   glUseProgram(0);
-  glBindTexture(texture_target_, 0);
 
   // Before leaving, put back to drawing to a single rendering output.
-  glDrawBuffers(1, kAttachments);
+  glDrawBuffers(1, kColorAttachments);
 
-  *texture_y = temp_texture_y.Release();
-  *texture_u = temp_texture_u.Release();
-  *texture_v = temp_texture_v.Release();
+  glBindTexture(texture_target_, 0);
+  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+
+  *texture_y = textures_[Y_PLANE_OUTPUT];
+  *texture_u = textures_[U_PLANE_OUTPUT];
+  *texture_v = textures_[V_PLANE_OUTPUT];
   return true;
 }
 
+void CompositingIOSurfaceTransformer::PrepareTexture(
+    CachedTexture which, const gfx::Size& size) {
+  DCHECK_GE(which, 0);
+  DCHECK_LT(which, NUM_CACHED_TEXTURES);
+  DCHECK(!size.IsEmpty());
+
+  if (!textures_[which]) {
+    glGenTextures(1, &textures_[which]);
+    DCHECK_NE(textures_[which], 0u);
+    texture_sizes_[which] = gfx::Size();
+  }
+
+  // Re-allocate the texture if its size has changed since last use.
+  if (texture_sizes_[which] != size) {

[ncarter (slow), 2013/04/15 23:38:19]

Might be worth TRACE_EVENTING this since it shouldn't happen commonly and would
be a perf warning if it does.

[miu, 2013/04/16 03:51:22]

Done.  Good call.

+    glBindTexture(texture_target_, textures_[which]);
+    glTexImage2D(texture_target_, 0, GL_RGBA, size.width(), size.height(), 0,
+                 GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
+    DCHECK(glGetError() == GL_NO_ERROR);

[ncarter (slow), 2013/04/15 23:38:19]

Why DCHECK glGetError() here specifically (is this debugging cruft?)

[miu, 2013/04/16 03:51:22]

Done.  Yep.  Leftover debugging cruft.  I had a problem and put these everywhere
to narrow down where the error occurred.

+    texture_sizes_[which] = size;
+  }
+}
+
+void CompositingIOSurfaceTransformer::PrepareFramebuffer() {
+  if (!frame_buffer_) {
+    glGenFramebuffersEXT(1, &frame_buffer_);
+    DCHECK_NE(frame_buffer_, 0u);
+  }
+}
+
 }  // namespace content