Merge changes 26766,26767 into eclair

* changes:
  turn dithering off if it's not needed
  fix [2142193] disable GL_LINEAR when not needed

libs/surfaceflinger/Layer.cpp

@@ -51,7 +51,8 @@ Layer::Layer(SurfaceFlinger* flinger, DisplayID display,
         const sp<Client>& c, int32_t i)
     :   LayerBaseClient(flinger, display, c, i),
         mSecure(false),
-        mNeedsBlending(true)
+        mNeedsBlending(true),
+        mNeedsDithering(false)
 {
     // no OpenGL operation is possible here, since we might not be
     // in the OpenGL thread.
@@ -106,10 +107,16 @@ status_t Layer::ditch()
 status_t Layer::setBuffers( uint32_t w, uint32_t h,
                             PixelFormat format, uint32_t flags)
 {
+    // this surfaces pixel format
     PixelFormatInfo info;
     status_t err = getPixelFormatInfo(format, &info);
     if (err) return err;
 
+    // the display's pixel format
+    const DisplayHardware& hw(graphicPlane(0).displayHardware());
+    PixelFormatInfo displayInfo;
+    getPixelFormatInfo(hw.getFormat(), &displayInfo);
+
     uint32_t bufferFlags = 0;
     if (flags & ISurfaceComposer::eSecure)
         bufferFlags |= Buffer::SECURE;
@@ -119,6 +126,12 @@ status_t Layer::setBuffers( uint32_t w, uint32_t h,
     mHeight = h;
     mSecure = (bufferFlags & Buffer::SECURE) ? true : false;
     mNeedsBlending = (info.h_alpha - info.l_alpha) > 0;
+
+    // we use the red index
+    int displayRedSize = displayInfo.getSize(PixelFormatInfo::INDEX_RED);
+    int layerRedsize = info.getSize(PixelFormatInfo::INDEX_RED);
+    mNeedsDithering = layerRedsize > displayRedSize;
+
     mBufferFlags = bufferFlags;
     for (size_t i=0 ; i<NUM_BUFFERS ; i++) {
         mBuffers[i] = new Buffer();

libs/surfaceflinger/Layer.h

@@ -68,6 +68,7 @@ public:
     virtual void unlockPageFlip(const Transform& planeTransform, Region& outDirtyRegion);
     virtual void finishPageFlip();
     virtual bool needsBlending() const      { return mNeedsBlending; }
+    virtual bool needsDithering() const     { return mNeedsDithering; }
     virtual bool isSecure() const           { return mSecure; }
     virtual sp<Surface> createSurface() const;
     virtual status_t ditch();
@@ -109,6 +110,7 @@ private:
             bool            mSecure;
             int32_t         mFrontBufferIndex;
             bool            mNeedsBlending;
+            bool            mNeedsDithering;
             Region          mPostedDirtyRegion;
             sp<FreezeLock>  mFreezeLock;
             PixelFormat     mFormat;

libs/surfaceflinger/LayerBase.cpp

@@ -56,6 +56,7 @@ LayerBase::LayerBase(SurfaceFlinger* flinger, DisplayID display)
     : dpy(display), contentDirty(false),
       mFlinger(flinger),
       mTransformed(false),
+      mUseLinearFiltering(false),
       mOrientation(0),
       mTransactionFlags(0),
       mPremultipliedAlpha(true),
@@ -208,7 +209,19 @@ uint32_t LayerBase::doTransaction(uint32_t flags)
         flags |= eVisibleRegion;
         this->contentDirty = true;
     }
-    
+
+    if (temp.sequence != front.sequence) {
+        const bool linearFiltering = mUseLinearFiltering;
+        mUseLinearFiltering = false;
+        if (!(mFlags & DisplayHardware::SLOW_CONFIG)) {
+            // we may use linear filtering, if the matrix scales us
+            const uint8_t type = temp.transform.getType();
+            if (!temp.transform.preserveRects() || (type >= Transform::SCALE)) {
+                mUseLinearFiltering = true;
+            }
+        }
+    }
+
     // Commit the transaction
     commitTransaction(flags & eRestartTransaction);
     return flags;
@@ -332,13 +345,8 @@ GLuint LayerBase::createTexture() const
     glBindTexture(GL_TEXTURE_2D, textureName);
     glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-    if (mFlags & DisplayHardware::SLOW_CONFIG) {
+    glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    } else {
-        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-    }
     return textureName;
 }
 
@@ -385,14 +393,6 @@ void LayerBase::drawWithOpenGL(const Region& clip, const Texture& texture) const
     
     glEnable(GL_TEXTURE_2D);
 
-    // Dithering...
-    bool fast = !(mFlags & DisplayHardware::SLOW_CONFIG);
-    if (fast || s.flags & ISurfaceComposer::eLayerDither) {
-        glEnable(GL_DITHER);
-    } else {
-        glDisable(GL_DITHER);
-    }
-
     if (UNLIKELY(s.alpha < 0xFF)) {
         // We have an alpha-modulation. We need to modulate all
         // texture components by alpha because we're always using 
@@ -434,12 +434,6 @@ void LayerBase::drawWithOpenGL(const Region& clip, const Texture& texture) const
         Region::const_iterator it = clip.begin();
         Region::const_iterator const end = clip.end();
         if (it != end) {
-            // always use high-quality filtering with fast configurations
-            bool fast = !(mFlags & DisplayHardware::SLOW_CONFIG);
-            if (!fast && s.flags & ISurfaceComposer::eLayerFilter) {
-                glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-                glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-            }            
             const GLfixed texCoords[4][2] = {
                     { 0,        0 },
                     { 0,        0x10000 },
@@ -481,11 +475,6 @@ void LayerBase::drawWithOpenGL(const Region& clip, const Texture& texture) const
                 glScissor(r.left, sy, r.width(), r.height());
                 glDrawArrays(GL_TRIANGLE_FAN, 0, 4); 
             }
-
-            if (!fast && s.flags & ISurfaceComposer::eLayerFilter) {
-                glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-                glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-            }
             glDisableClientState(GL_TEXTURE_COORD_ARRAY);
         }
     } else {
@@ -512,6 +501,19 @@ void LayerBase::validateTexture(GLint textureName) const
     glBindTexture(GL_TEXTURE_2D, textureName);
     // TODO: reload the texture if needed
     // this is currently done in loadTexture() below
+    if (mUseLinearFiltering) {
+        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    } else {
+        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    }
+
+    if (needsDithering()) {
+        glEnable(GL_DITHER);
+    } else {
+        glDisable(GL_DITHER);
+    }
 }
 
 void LayerBase::loadTexture(Texture* texture, GLint textureName, 

libs/surfaceflinger/LayerBase.h

@@ -187,6 +187,11 @@ public:
      */
     virtual bool needsBlending() const  { return false; }
 
+    /**
+     * needsDithering - true if this surface needs dithering
+     */
+    virtual bool needsDithering() const { return false; }
+
     /**
      * transformed -- true is this surface needs a to be transformed
      */
@@ -254,6 +259,7 @@ protected:
 
                 // cached during validateVisibility()
                 bool            mTransformed;
+                bool            mUseLinearFiltering;
                 int32_t         mOrientation;
                 GLfixed         mVertices[4][2];
                 Rect            mTransformedBounds;

libs/surfaceflinger/SurfaceFlinger.cpp

@@ -1497,11 +1497,12 @@ status_t SurfaceFlinger::dump(int fd, const Vector<String16>& args)
                     "+ %s %p\n"
                     "      "
                     "z=%9d, pos=(%4d,%4d), size=(%4d,%4d), "
-                    "needsBlending=%1d, invalidate=%1d, "
+                    "needsBlending=%1d, needsDithering=%1d, invalidate=%1d, "
                     "alpha=0x%02x, flags=0x%08x, tr=[%.2f, %.2f][%.2f, %.2f]\n",
                     layer->getTypeID(), layer.get(),
                     s.z, layer->tx(), layer->ty(), s.w, s.h,
-                    layer->needsBlending(), layer->contentDirty,
+                    layer->needsBlending(), layer->needsDithering(),
+                    layer->contentDirty,
                     s.alpha, s.flags,
                     s.transform[0], s.transform[1],
                     s.transform[2], s.transform[3]);

libs/surfaceflinger/Transform.h

@@ -50,6 +50,14 @@ public:
                 ROT_INVALID = 0x80000000
             };
 
+            enum type_mask {
+                IDENTITY            = 0,
+                TRANSLATE           = 0x1,
+                SCALE               = 0x2,
+                AFFINE              = 0x4,
+                PERSPECTIVE         = 0x8
+            };
+
             bool    transformed() const;
             int32_t getOrientation() const;
             bool    preserveRects() const;