Make sure set GL state properly

when taking a screenshot, in particular, we could end up
with stale GL state when drawing LayerDim which resulted
in incortect rendering.

Bug: 5467587
Change-Id: Id9fbed2843481d31063620f3662b364c7e3ac781

services/surfaceflinger/Layer.cpp

@@ -280,33 +280,33 @@ void Layer::onDraw(const Region& clip) const
         return;
     }
 
-    GLenum target = GL_TEXTURE_EXTERNAL_OES;
     if (!isProtected()) {
-        glBindTexture(target, mTextureName);
+        glBindTexture(GL_TEXTURE_EXTERNAL_OES, mTextureName);
+        GLenum filter = GL_NEAREST;
         if (getFiltering() || needsFiltering() || isFixedSize() || isCropped()) {
             // TODO: we could be more subtle with isFixedSize()
-            glTexParameterx(target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-            glTexParameterx(target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-        } else {
-            glTexParameterx(target, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-            glTexParameterx(target, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+            filter = GL_LINEAR;
         }
-        glEnable(target);
+        glTexParameterx(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, filter);
+        glTexParameterx(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MIN_FILTER, filter);
         glMatrixMode(GL_TEXTURE);
         glLoadMatrixf(mTextureMatrix);
         glMatrixMode(GL_MODELVIEW);
+        glEnable(GL_TEXTURE_EXTERNAL_OES);
+        glDisable(GL_TEXTURE_2D);
     } else {
-        target = GL_TEXTURE_2D;
-        glBindTexture(target, mFlinger->getProtectedTexName());
-        glEnable(target);
+        glBindTexture(GL_TEXTURE_2D, mFlinger->getProtectedTexName());
         glMatrixMode(GL_TEXTURE);
         glLoadIdentity();
         glMatrixMode(GL_MODELVIEW);
+        glDisable(GL_TEXTURE_EXTERNAL_OES);
+        glEnable(GL_TEXTURE_2D);
     }
 
     drawWithOpenGL(clip);
 
-    glDisable(target);
+    glDisable(GL_TEXTURE_EXTERNAL_OES);
+    glDisable(GL_TEXTURE_2D);
 }
 
 // As documented in libhardware header, formats in the range

services/surfaceflinger/LayerBase.cpp

@@ -388,14 +388,9 @@ void LayerBase::clearWithOpenGL(const Region& clip, GLclampf red,
     const uint32_t fbHeight = hw.getHeight();
     glColor4f(red,green,blue,alpha);
 
-#if defined(GL_OES_EGL_image_external)
-        if (GLExtensions::getInstance().haveTextureExternal()) {
-            glDisable(GL_TEXTURE_EXTERNAL_OES);
-        }
-#endif
+    glDisable(GL_TEXTURE_EXTERNAL_OES);
     glDisable(GL_TEXTURE_2D);
     glDisable(GL_BLEND);
-    glDisable(GL_DITHER);
 
     Region::const_iterator it = clip.begin();
     Region::const_iterator const end = clip.end();
@@ -457,12 +452,6 @@ void LayerBase::drawWithOpenGL(const Region& clip) const
     texCoords[3].u = 1;
     texCoords[3].v = 1;
 
-    if (needsDithering()) {
-        glEnable(GL_DITHER);
-    } else {
-        glDisable(GL_DITHER);
-    }
-
     glEnableClientState(GL_TEXTURE_COORD_ARRAY);
     glVertexPointer(2, GL_FLOAT, 0, mVertices);
     glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
@@ -476,6 +465,7 @@ void LayerBase::drawWithOpenGL(const Region& clip) const
         glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
     }
     glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+    glDisable(GL_BLEND);
 }
 
 void LayerBase::dump(String8& result, char* buffer, size_t SIZE) const

services/surfaceflinger/LayerDim.cpp

@@ -49,7 +49,8 @@ void LayerDim::onDraw(const Region& clip) const
         const DisplayHardware& hw(graphicPlane(0).displayHardware());
         const GLfloat alpha = s.alpha/255.0f;
         const uint32_t fbHeight = hw.getHeight();
-        glDisable(GL_DITHER);
+        glDisable(GL_TEXTURE_EXTERNAL_OES);
+        glDisable(GL_TEXTURE_2D);
 
         if (s.alpha == 0xFF) {
             glDisable(GL_BLEND);
@@ -60,11 +61,6 @@ void LayerDim::onDraw(const Region& clip) const
 
         glColor4f(0, 0, 0, alpha);
 
-#if defined(GL_OES_EGL_image_external)
-        if (GLExtensions::getInstance().haveTextureExternal()) {
-            glDisable(GL_TEXTURE_EXTERNAL_OES);
-        }
-#endif
         glVertexPointer(2, GL_FLOAT, 0, mVertices);
 
         while (it != end) {
@@ -73,8 +69,9 @@ void LayerDim::onDraw(const Region& clip) const
             glScissor(r.left, sy, r.width(), r.height());
             glDrawArrays(GL_TRIANGLE_FAN, 0, 4); 
         }
+        glDisable(GL_BLEND);
+        glDisableClientState(GL_TEXTURE_COORD_ARRAY);
     }
-    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
 }
 
 // ---------------------------------------------------------------------------

services/surfaceflinger/SurfaceFlinger.cpp

@@ -1029,8 +1029,9 @@ void SurfaceFlinger::debugFlashRegions()
         composeSurfaces(repaint);
     }
 
+    glDisable(GL_TEXTURE_EXTERNAL_OES);
+    glDisable(GL_TEXTURE_2D);
     glDisable(GL_BLEND);
-    glDisable(GL_DITHER);
     glDisable(GL_SCISSOR_TEST);
 
     static int toggle = 0;
@@ -1073,9 +1074,6 @@ void SurfaceFlinger::drawWormhole() const
     const int32_t width = hw.getWidth();
     const int32_t height = hw.getHeight();
 
-    glDisable(GL_BLEND);
-    glDisable(GL_DITHER);
-
     if (LIKELY(!mDebugBackground)) {
         glClearColor(0,0,0,0);
         Region::const_iterator it = region.begin();
@@ -1090,19 +1088,20 @@ void SurfaceFlinger::drawWormhole() const
         const GLshort vertices[][2] = { { 0, 0 }, { width, 0 },
                 { width, height }, { 0, height }  };
         const GLshort tcoords[][2] = { { 0, 0 }, { 1, 0 },  { 1, 1 }, { 0, 1 } };
+
         glVertexPointer(2, GL_SHORT, 0, vertices);
         glTexCoordPointer(2, GL_SHORT, 0, tcoords);
         glEnableClientState(GL_TEXTURE_COORD_ARRAY);
-#if defined(GL_OES_EGL_image_external)
-        if (GLExtensions::getInstance().haveTextureExternal()) {
-            glDisable(GL_TEXTURE_EXTERNAL_OES);
-        }
-#endif
+
+        glDisable(GL_TEXTURE_EXTERNAL_OES);
         glEnable(GL_TEXTURE_2D);
         glBindTexture(GL_TEXTURE_2D, mWormholeTexName);
         glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
         glMatrixMode(GL_TEXTURE);
         glLoadIdentity();
+
+        glDisable(GL_BLEND);
+
         glScalef(width*(1.0f/32.0f), height*(1.0f/32.0f), 1);
         Region::const_iterator it = region.begin();
         Region::const_iterator const end = region.end();
@@ -1813,6 +1812,8 @@ status_t SurfaceFlinger::renderScreenToTextureLocked(DisplayID dpy,
             GL_COLOR_ATTACHMENT0_OES, GL_TEXTURE_2D, tname, 0);
 
     // redraw the screen entirely...
+    glDisable(GL_TEXTURE_EXTERNAL_OES);
+    glDisable(GL_TEXTURE_2D);
     glClearColor(0,0,0,1);
     glClear(GL_COLOR_BUFFER_BIT);
     glMatrixMode(GL_MODELVIEW);
@@ -2004,6 +2005,7 @@ status_t SurfaceFlinger::electronBeamOffAnimationImplLocked()
     glDisableClientState(GL_TEXTURE_COORD_ARRAY);
     glDeleteTextures(1, &tname);
     glDisable(GL_TEXTURE_2D);
+    glDisable(GL_BLEND);
     return NO_ERROR;
 }
 
@@ -2148,6 +2150,7 @@ status_t SurfaceFlinger::electronBeamOnAnimationImplLocked()
     glDisableClientState(GL_TEXTURE_COORD_ARRAY);
     glDeleteTextures(1, &tname);
     glDisable(GL_TEXTURE_2D);
+    glDisable(GL_BLEND);
 
     return NO_ERROR;
 }