Add stroke support to polygonal shape rendering

bug:4419017
bug:7230005

- Adds support for stroke/strokeAndFill for shapes without joins
- Fixes path-polygonization threshold calculation
- Fixes rendering offset (now only used for points)
- Several formatting fixes

Change-Id: If72473dc881e45752e2ec212d0dcd1e3f97979ea

Author: ChrisCraik

libs/hwui/Caches.cpp

@@ -68,6 +68,7 @@ void Caches::init() {
     mCurrentBuffer = meshBuffer;
     mCurrentIndicesBuffer = 0;
     mCurrentPositionPointer = this;
+    mCurrentPositionStride = 0;
     mCurrentTexCoordsPointer = this;
 
     mTexCoordsArrayEnabled = false;
@@ -340,15 +341,18 @@ bool Caches::unbindIndicesBuffer() {
 // Meshes and textures
 ///////////////////////////////////////////////////////////////////////////////
 
-void Caches::bindPositionVertexPointer(bool force, GLuint slot, GLvoid* vertices, GLsizei stride) {
-    if (force || vertices != mCurrentPositionPointer) {
+void Caches::bindPositionVertexPointer(bool force, GLvoid* vertices, GLsizei stride) {
+    if (force || vertices != mCurrentPositionPointer || stride != mCurrentPositionStride) {
+        GLuint slot = currentProgram->position;
         glVertexAttribPointer(slot, 2, GL_FLOAT, GL_FALSE, stride, vertices);
         mCurrentPositionPointer = vertices;
+        mCurrentPositionStride = stride;
     }
 }
 
-void Caches::bindTexCoordsVertexPointer(bool force, GLuint slot, GLvoid* vertices) {
+void Caches::bindTexCoordsVertexPointer(bool force, GLvoid* vertices) {
     if (force || vertices != mCurrentTexCoordsPointer) {
+        GLuint slot = currentProgram->texCoords;
         glVertexAttribPointer(slot, 2, GL_FLOAT, GL_FALSE, gMeshStride, vertices);
         mCurrentTexCoordsPointer = vertices;
     }

libs/hwui/Caches.h

@@ -173,14 +173,13 @@ class ANDROID_API Caches: public Singleton<Caches> {
      * Binds an attrib to the specified float vertex pointer.
      * Assumes a stride of gMeshStride and a size of 2.
      */
-    void bindPositionVertexPointer(bool force, GLuint slot, GLvoid* vertices,
-            GLsizei stride = gMeshStride);
+    void bindPositionVertexPointer(bool force, GLvoid* vertices, GLsizei stride = gMeshStride);
 
     /**
      * Binds an attrib to the specified float vertex pointer.
      * Assumes a stride of gMeshStride and a size of 2.
      */
-    void bindTexCoordsVertexPointer(bool force, GLuint slot, GLvoid* vertices);
+    void bindTexCoordsVertexPointer(bool force, GLvoid* vertices);
 
     /**
      * Resets the vertex pointers.
@@ -295,6 +294,7 @@ class ANDROID_API Caches: public Singleton<Caches> {
     GLuint mCurrentBuffer;
     GLuint mCurrentIndicesBuffer;
     void* mCurrentPositionPointer;
+    GLuint mCurrentPositionStride;
     void* mCurrentTexCoordsPointer;
 
     bool mTexCoordsArrayEnabled;

libs/hwui/FontRenderer.cpp

@@ -374,9 +374,8 @@ void FontRenderer::issueDrawCommand() {
         int offset = 2;
 
         bool force = caches.unbindMeshBuffer();
-        caches.bindPositionVertexPointer(force, caches.currentProgram->position, buffer);
-        caches.bindTexCoordsVertexPointer(force, caches.currentProgram->texCoords,
-                buffer + offset);
+        caches.bindPositionVertexPointer(force, buffer);
+        caches.bindTexCoordsVertexPointer(force, buffer + offset);
     }
 
     glDrawElements(GL_TRIANGLES, mCurrentQuadIndex * 6, GL_UNSIGNED_SHORT, NULL);

libs/hwui/OpenGLRenderer.cpp

@@ -1248,6 +1248,15 @@ bool OpenGLRenderer::quickRejectNoScissor(float left, float top, float right, fl
     return !clip.intersects(transformed);
 }
 
+bool OpenGLRenderer::quickRejectPreStroke(float left, float top, float right, float bottom, SkPaint* paint) {
+    if (paint->getStyle() != SkPaint::kFill_Style) {
+        float outset = paint->getStrokeWidth() * 0.5f;
+        return quickReject(left - outset, top - outset, right + outset, bottom + outset);
+    } else {
+        return quickReject(left, top, right, bottom);
+    }
+}
+
 bool OpenGLRenderer::quickReject(float left, float top, float right, float bottom) {
     if (mSnapshot->isIgnored()) {
         return true;
@@ -1490,7 +1499,7 @@ void OpenGLRenderer::setupDrawTextGammaUniforms() {
 
 void OpenGLRenderer::setupDrawSimpleMesh() {
     bool force = mCaches.bindMeshBuffer();
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position, 0);
+    mCaches.bindPositionVertexPointer(force, 0);
     mCaches.unbindIndicesBuffer();
 }
 
@@ -1523,26 +1532,25 @@ void OpenGLRenderer::setupDrawMesh(GLvoid* vertices, GLvoid* texCoords, GLuint v
         force = mCaches.unbindMeshBuffer();
     }
 
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position, vertices);
+    mCaches.bindPositionVertexPointer(force, vertices);
     if (mCaches.currentProgram->texCoords >= 0) {
-        mCaches.bindTexCoordsVertexPointer(force, mCaches.currentProgram->texCoords, texCoords);
+        mCaches.bindTexCoordsVertexPointer(force, texCoords);
     }
 
     mCaches.unbindIndicesBuffer();
 }
 
 void OpenGLRenderer::setupDrawMeshIndices(GLvoid* vertices, GLvoid* texCoords) {
     bool force = mCaches.unbindMeshBuffer();
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position, vertices);
+    mCaches.bindPositionVertexPointer(force, vertices);
     if (mCaches.currentProgram->texCoords >= 0) {
-        mCaches.bindTexCoordsVertexPointer(force, mCaches.currentProgram->texCoords, texCoords);
+        mCaches.bindTexCoordsVertexPointer(force, texCoords);
     }
 }
 
 void OpenGLRenderer::setupDrawVertices(GLvoid* vertices) {
     bool force = mCaches.unbindMeshBuffer();
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position,
-            vertices, gVertexStride);
+    mCaches.bindPositionVertexPointer(force, vertices, gVertexStride);
     mCaches.unbindIndicesBuffer();
 }
 
@@ -1560,8 +1568,7 @@ void OpenGLRenderer::setupDrawVertices(GLvoid* vertices) {
 void OpenGLRenderer::setupDrawAALine(GLvoid* vertices, GLvoid* widthCoords,
         GLvoid* lengthCoords, float boundaryWidthProportion, int& widthSlot, int& lengthSlot) {
     bool force = mCaches.unbindMeshBuffer();
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position,
-            vertices, gAAVertexStride);
+    mCaches.bindPositionVertexPointer(force, vertices, gAAVertexStride);
     mCaches.resetTexCoordsVertexPointer();
     mCaches.unbindIndicesBuffer();
 
@@ -1919,15 +1926,23 @@ status_t OpenGLRenderer::drawPatch(SkBitmap* bitmap, const int32_t* xDivs, const
 }
 
 /**
- * This function uses a similar approach to that of AA lines in the drawLines() function.
- * We expand the rectangle by a half pixel in screen space on all sides. However, instead of using
- * a fragment shader to compute the translucency of the color from its position, we simply use a
- * varying parameter to define how far a given pixel is into the region.
+ * Renders a convex path via tessellation. For AA paths, this function uses a similar approach to
+ * that of AA lines in the drawLines() function.  We expand the convex path by a half pixel in
+ * screen space in all directions. However, instead of using a fragment shader to compute the
+ * translucency of the color from its position, we simply use a varying parameter to define how far
+ * a given pixel is from the edge. For non-AA paths, the expansion and alpha varying are not used.
+ *
+ * Doesn't yet support joins, caps, or path effects.
  */
-void OpenGLRenderer::drawConvexPath(const SkPath& path, int color, SkXfermode::Mode mode, bool isAA) {
+void OpenGLRenderer::drawConvexPath(const SkPath& path, SkPaint* paint) {
+    int color = paint->getColor();
+    SkPaint::Style style = paint->getStyle();
+    SkXfermode::Mode mode = getXfermode(paint->getXfermode());
+    bool isAA = paint->isAntiAlias();
+
     VertexBuffer vertexBuffer;
     // TODO: try clipping large paths to viewport
-    PathRenderer::convexPathFillVertices(path, mSnapshot->transform, vertexBuffer, isAA);
+    PathRenderer::convexPathVertices(path, paint, mSnapshot->transform, vertexBuffer);
 
     setupDraw();
     setupDrawNoTexture();
@@ -1938,15 +1953,14 @@ void OpenGLRenderer::drawConvexPath(const SkPath& path, int color, SkXfermode::M
     setupDrawShader();
     setupDrawBlending(isAA, mode);
     setupDrawProgram();
-    setupDrawModelViewIdentity(true);
+    setupDrawModelViewIdentity();
     setupDrawColorUniforms();
     setupDrawColorFilterUniforms();
     setupDrawShaderIdentityUniforms();
 
     void* vertices = vertexBuffer.getBuffer();
     bool force = mCaches.unbindMeshBuffer();
-    mCaches.bindPositionVertexPointer(force, mCaches.currentProgram->position,
-                                      vertices, isAA ? gAlphaVertexStride : gVertexStride);
+    mCaches.bindPositionVertexPointer(true, vertices, isAA ? gAlphaVertexStride : gVertexStride);
     mCaches.resetTexCoordsVertexPointer();
     mCaches.unbindIndicesBuffer();
 
@@ -1960,7 +1974,7 @@ void OpenGLRenderer::drawConvexPath(const SkPath& path, int color, SkXfermode::M
         glVertexAttribPointer(alphaSlot, 1, GL_FLOAT, GL_FALSE, gAlphaVertexStride, alphaCoords);
     }
 
-    SkRect bounds = path.getBounds();
+    SkRect bounds = PathRenderer::computePathBounds(path, paint);
     dirtyLayer(bounds.fLeft, bounds.fTop, bounds.fRight, bounds.fBottom, *mSnapshot->transform);
 
     glDrawArrays(GL_TRIANGLE_STRIP, 0, vertexBuffer.getSize());
@@ -2050,7 +2064,7 @@ status_t OpenGLRenderer::drawLines(float* points, int count, SkPaint* paint) {
     setupDrawShader();
     setupDrawBlending(isAA, mode);
     setupDrawProgram();
-    setupDrawModelViewIdentity(true);
+    setupDrawModelViewIdentity();
     setupDrawColorUniforms();
     setupDrawColorFilterUniforms();
     setupDrawShaderIdentityUniforms();
@@ -2330,11 +2344,11 @@ status_t OpenGLRenderer::drawShape(float left, float top, const PathTexture* tex
 
 status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float bottom,
         float rx, float ry, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickReject(left, top, right, bottom)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
         return DrawGlInfo::kStatusDone;
     }
 
-    if (p->getStyle() != SkPaint::kFill_Style) {
+    if (p->getPathEffect() != 0) {
         mCaches.activeTexture(0);
         const PathTexture* texture = mCaches.roundRectShapeCache.getRoundRect(
                 right - left, bottom - top, rx, ry, p);
@@ -2343,46 +2357,59 @@ status_t OpenGLRenderer::drawRoundRect(float left, float top, float right, float
 
     SkPath path;
     SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
+    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
+        float outset = p->getStrokeWidth() / 2;
+        rect.outset(outset, outset);
+        rx += outset;
+        ry += outset;
+    }
     path.addRoundRect(rect, rx, ry);
-    drawConvexPath(path, p->getColor(), getXfermode(p->getXfermode()), p->isAntiAlias());
+    drawConvexPath(path, p);
 
     return DrawGlInfo::kStatusDrew;
 }
 
 status_t OpenGLRenderer::drawCircle(float x, float y, float radius, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickReject(x - radius, y - radius, x + radius, y + radius)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(x - radius, y - radius,
+            x + radius, y + radius, p)) {
         return DrawGlInfo::kStatusDone;
     }
-
-    if (p->getStyle() != SkPaint::kFill_Style) {
+    if (p->getPathEffect() != 0) {
         mCaches.activeTexture(0);
         const PathTexture* texture = mCaches.circleShapeCache.getCircle(radius, p);
         return drawShape(x - radius, y - radius, texture, p);
     }
 
     SkPath path;
-    path.addCircle(x, y, radius);
-    drawConvexPath(path, p->getColor(), getXfermode(p->getXfermode()), p->isAntiAlias());
+    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
+        path.addCircle(x, y, radius + p->getStrokeWidth() / 2);
+    } else {
+        path.addCircle(x, y, radius);
+    }
+    drawConvexPath(path, p);
 
     return DrawGlInfo::kStatusDrew;
 }
 
 status_t OpenGLRenderer::drawOval(float left, float top, float right, float bottom,
         SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickReject(left, top, right, bottom)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
         return DrawGlInfo::kStatusDone;
     }
 
-    if (p->getStyle() != SkPaint::kFill_Style) {
+    if (p->getPathEffect() != 0) {
         mCaches.activeTexture(0);
         const PathTexture* texture = mCaches.ovalShapeCache.getOval(right - left, bottom - top, p);
         return drawShape(left, top, texture, p);
     }
 
     SkPath path;
     SkRect rect = SkRect::MakeLTRB(left, top, right, bottom);
+    if (p->getStyle() == SkPaint::kStrokeAndFill_Style) {
+        rect.outset(p->getStrokeWidth() / 2, p->getStrokeWidth() / 2);
+    }
     path.addOval(rect);
-    drawConvexPath(path, p->getColor(), getXfermode(p->getXfermode()), p->isAntiAlias());
+    drawConvexPath(path, p);
 
     return DrawGlInfo::kStatusDrew;
 }
@@ -2402,10 +2429,11 @@ status_t OpenGLRenderer::drawArc(float left, float top, float right, float botto
 }
 
 status_t OpenGLRenderer::drawRect(float left, float top, float right, float bottom, SkPaint* p) {
-    if (mSnapshot->isIgnored() || quickReject(left, top, right, bottom)) {
+    if (mSnapshot->isIgnored() || quickRejectPreStroke(left, top, right, bottom, p)) {
         return DrawGlInfo::kStatusDone;
     }
 
+    // only fill style is supported by drawConvexPath, since others have to handle joins
     if (p->getStyle() != SkPaint::kFill_Style) {
         mCaches.activeTexture(0);
         const PathTexture* texture = mCaches.rectShapeCache.getRect(right - left, bottom - top, p);
@@ -2415,7 +2443,7 @@ status_t OpenGLRenderer::drawRect(float left, float top, float right, float bott
     if (p->isAntiAlias() && !mSnapshot->transform->isSimple()) {
         SkPath path;
         path.addRect(left, top, right, bottom);
-        drawConvexPath(path, p->getColor(), getXfermode(p->getXfermode()), true);
+        drawConvexPath(path, p);
     } else {
         drawColorRect(left, top, right, bottom, p->getColor(), getXfermode(p->getXfermode()));
     }

libs/hwui/OpenGLRenderer.h

@@ -406,6 +406,11 @@ class OpenGLRenderer {
     bool quickRejectNoScissor(float left, float top, float right, float bottom,
             Rect& transformed, Rect& clip);
 
+    /**
+     * Performs a quick reject but adjust the bounds to account for stroke width if necessary
+     */
+    bool quickRejectPreStroke(float left, float top, float right, float bottom, SkPaint* paint);
+
     /**
      * Creates a new layer stored in the specified snapshot.
      *
@@ -513,11 +518,9 @@ class OpenGLRenderer {
      * Renders the convex hull defined by the specified path as a strip of polygons.
      *
      * @param path The hull of the path to draw
-     * @param color The color of the rect
-     * @param mode The blending mode to draw the path
-     * @param isAA True if the drawing should be anti-aliased
+     * @param paint The paint to render with
      */
-    void drawConvexPath(const SkPath& path, int color, SkXfermode::Mode mode, bool isAA);
+    void drawConvexPath(const SkPath& path, SkPaint* paint);
 
     /**
      * Draws a textured rectangle with the specified texture. The specified coordinates