gpu: Use a rectangle to keep track of the cleared area of each texture level.

gpu/command_buffer/service/texture_manager.h

Index: gpu/command_buffer/service/texture_manager.h
diff --git a/gpu/command_buffer/service/texture_manager.h b/gpu/command_buffer/service/texture_manager.h
index d9576f7e58755cb6b3138759e950d97d32ddd8c5..b1f80d0c2ca4c6f97ff022889239c82cca0f0995 100644
--- a/gpu/command_buffer/service/texture_manager.h
+++ b/gpu/command_buffer/service/texture_manager.h
@@ -17,6 +17,7 @@
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/memory_tracking.h"
 #include "gpu/gpu_export.h"
+#include "ui/gfx/geometry/rect.h"
 #include "ui/gl/gl_image.h"
 
 namespace gpu {
@@ -92,10 +93,6 @@ class GPU_EXPORT Texture {
     return max_level_;
   }
 
-  int num_uncleared_mips() const {
-    return num_uncleared_mips_;
-  }
-
   uint32 estimated_size() const {
     return estimated_size_;
   }
@@ -182,6 +179,10 @@ class GPU_EXPORT Texture {
     return immutable_;
   }
 
+  // Get the cleared rectangle for a particular level. Returns an empty
+  // rectangle if level does not exist.
+  gfx::Rect GetLevelClearedRect(GLenum target, GLint level) const;
+
   // Whether a particular level/face is cleared.
   bool IsLevelCleared(GLenum target, GLint level) const;
 
@@ -227,7 +228,7 @@ class GPU_EXPORT Texture {
     LevelInfo(const LevelInfo& rhs);
     ~LevelInfo();
 
-    bool cleared;
+    gfx::Rect cleared_rect;
     GLenum target;
     GLint level;
     GLenum internal_format;
@@ -250,18 +251,17 @@ class GPU_EXPORT Texture {
   };
 
   // Set the info for a particular level.
-  void SetLevelInfo(
-      const FeatureInfo* feature_info,
-      GLenum target,
-      GLint level,
-      GLenum internal_format,
-      GLsizei width,
-      GLsizei height,
-      GLsizei depth,
-      GLint border,
-      GLenum format,
-      GLenum type,
-      bool cleared);
+  void SetLevelInfo(const FeatureInfo* feature_info,
+                    GLenum target,
+                    GLint level,
+                    GLenum internal_format,
+                    GLsizei width,
+                    GLsizei height,
+                    GLsizei depth,
+                    GLint border,
+                    GLenum format,
+                    GLenum type,
+                    const gfx::Rect& cleared_rect);
 
   // In GLES2 "texture complete" means it has all required mips for filtering
   // down to a 1x1 pixel texture, they are in the correct order, they are all
@@ -281,12 +281,14 @@ class GPU_EXPORT Texture {
     return npot_;
   }
 
+  // Marks a |rect| of a particular level as cleared.
+  void SetLevelClearedRect(GLenum target,
+                           GLint level,
+                           const gfx::Rect& cleared_rect);
+
   // Marks a particular level as cleared or uncleared.
   void SetLevelCleared(GLenum target, GLint level, bool cleared);
 
-  // Updates the cleared flag for this texture by inspecting all the mips.
-  void UpdateCleared();
-
   // Clears any renderable uncleared levels.
   // Returns false if a GL error was generated.
   bool ClearRenderableLevels(GLES2Decoder* decoder);
@@ -370,11 +372,7 @@ class GPU_EXPORT Texture {
 
   // Updates the unsafe textures count in all the managers referencing this
   // texture.
-  void UpdateSafeToRenderFrom(bool cleared);
-
-  // Updates the uncleared mip count in all the managers referencing this
-  // texture.
-  void UpdateMipCleared(LevelInfo* info, bool cleared);
+  void UpdateSafeToRenderFrom();
 
   // Computes the CanRenderCondition flag.
   CanRenderCondition GetCanRenderCondition() const;
@@ -410,7 +408,6 @@ class GPU_EXPORT Texture {
   // Whether all renderable mips of this texture have been cleared.
   bool cleared_;
 
-  int num_uncleared_mips_;
   int num_npot_faces_;
 
   // The target. 0 if unset, otherwise GL_TEXTURE_2D or GL_TEXTURE_CUBE_MAP.
@@ -649,27 +646,25 @@ class GPU_EXPORT TextureManager {
       GLenum target);
 
   // Set the info for a particular level in a TexureInfo.
-  void SetLevelInfo(
-      TextureRef* ref,
-      GLenum target,
-      GLint level,
-      GLenum internal_format,
-      GLsizei width,
-      GLsizei height,
-      GLsizei depth,
-      GLint border,
-      GLenum format,
-      GLenum type,
-      bool cleared);
+  void SetLevelInfo(TextureRef* ref,
+                    GLenum target,
+                    GLint level,
+                    GLenum internal_format,
+                    GLsizei width,
+                    GLsizei height,
+                    GLsizei depth,
+                    GLint border,
+                    GLenum format,
+                    GLenum type,
+                    const gfx::Rect& cleared_rect);
 
   // Adapter to call above function.
   void SetLevelInfoFromParams(TextureRef* ref,
                               const gpu::AsyncTexImage2DParams& params) {
-    SetLevelInfo(
-        ref, params.target, params.level, params.internal_format,
-        params.width, params.height, 1 /* depth */,
-        params.border, params.format,
-        params.type, true /* cleared */);
+    SetLevelInfo(ref, params.target, params.level, params.internal_format,
+                 params.width, params.height, 1 /* depth */, params.border,
+                 params.format, params.type,
+                 gfx::Rect(params.width, params.height) /* cleared_rect */);
   }
 
   Texture* Produce(TextureRef* ref);
@@ -677,6 +672,12 @@ class GPU_EXPORT TextureManager {
   // Maps an existing texture into the texture manager, at a given client ID.
   TextureRef* Consume(GLuint client_id, Texture* texture);
 
+  // Sets |rect| of mip as cleared.
+  void SetLevelClearedRect(TextureRef* ref,
+                           GLenum target,
+                           GLint level,
+                           const gfx::Rect& cleared_rect);
+
   // Sets a mip as cleared.
   void SetLevelCleared(TextureRef* ref, GLenum target,
                        GLint level, bool cleared);
@@ -739,10 +740,6 @@ class GPU_EXPORT TextureManager {
     return num_unsafe_textures_ > 0;
   }
 
-  bool HaveUnclearedMips() const {
-    return num_uncleared_mips_ > 0;
-  }
-
   bool HaveImages() const {
     return num_images_ > 0;
   }
@@ -862,7 +859,6 @@ class GPU_EXPORT TextureManager {
   void StopTracking(TextureRef* texture);
 
   void UpdateSafeToRenderFrom(int delta);
-  void UpdateUnclearedMips(int delta);
   void UpdateCanRenderCondition(Texture::CanRenderCondition old_condition,
                                 Texture::CanRenderCondition new_condition);
   void UpdateNumImages(int delta);
@@ -894,7 +890,6 @@ class GPU_EXPORT TextureManager {
 
   int num_unrenderable_textures_;
   int num_unsafe_textures_;
-  int num_uncleared_mips_;
   int num_images_;
 
   // Counts the number of Textures allocated with 'this' as its manager.