Implement drawDRRect for GPU

src/gpu/GrOvalRenderer.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrOvalRenderer.h"
 
 #include "GrEffect.h"
 #include "gl/GrGLEffect.h"
 #include "gl/GrGLSL.h"
 #include "gl/GrGLVertexEffect.h"
 #include "GrTBackendEffectFactory.h"
 
 #include "GrDrawState.h"
 #include "GrDrawTarget.h"
 #include "GrGpu.h"
 
 #include "SkRRect.h"
 #include "SkStrokeRec.h"
+#include "SkTLazy.h"
 
 #include "effects/GrVertexEffect.h"
+#include "effects/GrRRectEffect.h"
 
 namespace {
 
 struct CircleVertex {
     SkPoint  fPos;
     SkPoint  fOffset;
     SkScalar fOuterRadius;
     SkScalar fInnerRadius;
 };
 
@@ skipping 478 matching lines @@
 
     GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
     if (!geo.succeeded()) {
         GrPrintf("Failed to get space for vertices!\n");
         return;
     }
 
     CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
 
     SkStrokeRec::Style style = stroke.getStyle();
-    bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
+    bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
+                        SkStrokeRec::kHairline_Style == style;
+    bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
 
     SkScalar innerRadius = 0.0f;
     SkScalar outerRadius = radius;
     SkScalar halfWidth = 0;
-    if (style != SkStrokeRec::kFill_Style) {
+    if (hasStroke) {
         if (SkScalarNearlyZero(strokeWidth)) {
             halfWidth = SK_ScalarHalf;
         } else {
             halfWidth = SkScalarHalf(strokeWidth);
         }
 
         outerRadius += halfWidth;
-        if (isStroked) {
+        if (isStrokeOnly) {
             innerRadius = radius - halfWidth;
         }
     }
 
-    GrEffectRef* effect = CircleEdgeEffect::Create(isStroked && innerRadius > 0);
+    GrEffectRef* effect = CircleEdgeEffect::Create(isStrokeOnly && innerRadius > 0);
     static const int kCircleEdgeAttrIndex = 1;
     drawState->addCoverageEffect(effect, kCircleEdgeAttrIndex)->unref();
 
     // The radii are outset for two reasons. First, it allows the shader to simply perform
     // clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
     // verts of the bounding box that is rendered and the outset ensures the box will cover all
     // pixels partially covered by the circle.
     outerRadius += SK_ScalarHalf;
     innerRadius -= SK_ScalarHalf;
 
@@ skipping 68 matching lines @@
     SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*ellipseXRadius +
                                    vm[SkMatrix::kMScaleY]*ellipseYRadius);
 
     // do (potentially) anisotropic mapping of stroke
     SkVector scaledStroke;
     SkScalar strokeWidth = stroke.getWidth();
     scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] + vm[SkMatrix::kMSkewY]));
     scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] + vm[SkMatrix::kMScaleY]));
 
     SkStrokeRec::Style style = stroke.getStyle();
-    bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
+    bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
+                        SkStrokeRec::kHairline_Style == style;
+    bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
 
     SkScalar innerXRadius = 0;
     SkScalar innerYRadius = 0;
-    if (SkStrokeRec::kFill_Style != style) {
+    if (hasStroke) {
         if (SkScalarNearlyZero(scaledStroke.length())) {
             scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
         } else {
             scaledStroke.scale(SK_ScalarHalf);
         }
 
         // we only handle thick strokes for near-circular ellipses
         if (scaledStroke.length() > SK_ScalarHalf &&
             (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
             return false;
         }
 
         // we don't handle it if curvature of the stroke is less than curvature of the ellipse
         if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
             scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
             return false;
         }
 
         // this is legit only if scale & translation (which should be the case at the moment)
-        if (isStroked) {
+        if (isStrokeOnly) {
             innerXRadius = xRadius - scaledStroke.fX;
             innerYRadius = yRadius - scaledStroke.fY;
         }
 
         xRadius += scaledStroke.fX;
         yRadius += scaledStroke.fY;
     }
 
     GrDrawState::AutoViewMatrixRestore avmr;
     if (!avmr.setIdentity(drawState)) {
         return false;
     }
 
     drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs));
     SkASSERT(sizeof(EllipseVertex) == drawState->getVertexSize());
 
     GrDrawTarget::AutoReleaseGeometry geo(target, 4, 0);
     if (!geo.succeeded()) {
         GrPrintf("Failed to get space for vertices!\n");
         return false;
     }
 
     EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
 
-    GrEffectRef* effect = EllipseEdgeEffect::Create(isStroked &&
+    GrEffectRef* effect = EllipseEdgeEffect::Create(isStrokeOnly &&
                                                     innerXRadius > 0 && innerYRadius > 0);
 
     static const int kEllipseCenterAttrIndex = 1;
     static const int kEllipseEdgeAttrIndex = 2;
     drawState->addCoverageEffect(effect, kEllipseCenterAttrIndex, kEllipseEdgeAttrIndex)->unref();
 
     // Compute the reciprocals of the radii here to save time in the shader
     SkScalar xRadRecip = SkScalarInvert(xRadius);
     SkScalar yRadRecip = SkScalarInvert(yRadius);
     SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
@@ skipping 181 matching lines @@
             bool updated =
 #endif
             fRRectIndexBuffer->updateData(gRRectIndices,
                                           sizeof(gRRectIndices));
             GR_DEBUGASSERT(updated);
         }
     }
     return fRRectIndexBuffer;
 }
 
-bool GrOvalRenderer::drawSimpleRRect(GrDrawTarget* target, GrContext* context, bool useAA,
-                                     const SkRRect& rrect, const SkStrokeRec& stroke)
-{
+bool GrOvalRenderer::drawDRRect(GrDrawTarget* target, GrContext* context, bool useAA,
+                                const SkRRect& outer, const SkRRect& origInner) {
+    GrDrawState::AutoRestoreEffects are;
+    if (!origInner.isEmpty()) {
+        SkTCopyOnFirstWrite<SkRRect> inner(origInner);
+        if (!context->getMatrix().isIdentity()) {
+            if (!origInner.transform(context->getMatrix(), inner.writable())) {
+                return false;
+            }
+        }
+        bool applyAA = useAA &&
+                       !target->getDrawState().getRenderTarget()->isMultisampled() &&
+                       !target->shouldDisableCoverageAAForBlend();
+        GrEffectEdgeType edgeType = applyAA ? kInverseFillAA_GrEffectEdgeType :
+                                              kInverseFillBW_GrEffectEdgeType;
+        GrEffectRef* effect = GrRRectEffect::Create(edgeType, *inner);
+        if (NULL == effect) {
+            return false;
+        }
+        are.set(target->drawState());
+        target->drawState()->addCoverageEffect(effect)->unref();
+    }
+
+    SkStrokeRec fillRec(SkStrokeRec::kFill_InitStyle);
+    return this->drawRRect(target, context, useAA, outer, fillRec);
+}
+
+bool GrOvalRenderer::drawRRect(GrDrawTarget* target, GrContext* context, bool useAA,
+                               const SkRRect& rrect, const SkStrokeRec& stroke) {
+    if (rrect.isOval()) {
+        return this->drawOval(target, context, useAA, rrect.getBounds(), stroke);
+    }
+
     bool useCoverageAA = useAA &&
         !target->getDrawState().getRenderTarget()->isMultisampled() &&
         !target->shouldDisableCoverageAAForBlend();
 
     // only anti-aliased rrects for now
     if (!useCoverageAA) {
         return false;
     }
 
     const SkMatrix& vm = context->getMatrix();
-#ifdef SK_DEBUG
-    {
-        // we should have checked for this previously
-        SkASSERT(useCoverageAA && vm.rectStaysRect() && rrect.isSimple());
+
+    if (!vm.rectStaysRect() || !rrect.isSimple()) {
+        return false;
     }
-#endif
 
     // do any matrix crunching before we reset the draw state for device coords
     const SkRect& rrectBounds = rrect.getBounds();
     SkRect bounds;
     vm.mapRect(&bounds, rrectBounds);
 
     SkVector radii = rrect.getSimpleRadii();
     SkScalar xRadius = SkScalarAbs(vm[SkMatrix::kMScaleX]*radii.fX +
                                    vm[SkMatrix::kMSkewY]*radii.fY);
     SkScalar yRadius = SkScalarAbs(vm[SkMatrix::kMSkewX]*radii.fX +
                                    vm[SkMatrix::kMScaleY]*radii.fY);
 
-    // if hairline stroke is greater than radius, we don't handle that right now
     SkStrokeRec::Style style = stroke.getStyle();
-    if (SkStrokeRec::kHairline_Style == style &&
-        (SK_ScalarHalf > xRadius || SK_ScalarHalf > yRadius)) {
-        return false;
-    }
 
     // do (potentially) anisotropic mapping of stroke
     SkVector scaledStroke;
     SkScalar strokeWidth = stroke.getWidth();
-    scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] + vm[SkMatrix::kMSkewY]));
-    scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] + vm[SkMatrix::kMScaleY]));
 
-    // if half of strokewidth is greater than radius, we don't handle that right now
-    if (SK_ScalarHalf*scaledStroke.fX > xRadius || SK_ScalarHalf*scaledStroke.fY > yRadius) {
+    bool isStrokeOnly = SkStrokeRec::kStroke_Style == style ||
+                        SkStrokeRec::kHairline_Style == style;
+    bool hasStroke = isStrokeOnly || SkStrokeRec::kStrokeAndFill_Style == style;
+
+    if (hasStroke) {
+        if (SkStrokeRec::kHairline_Style == style) {
+            scaledStroke.set(1, 1);
+        } else {
+            scaledStroke.fX = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMScaleX] +
+                                                       vm[SkMatrix::kMSkewY]));
+            scaledStroke.fY = SkScalarAbs(strokeWidth*(vm[SkMatrix::kMSkewX] +
+                                                       vm[SkMatrix::kMScaleY]));
+        }
+
+        // if half of strokewidth is greater than radius, we don't handle that right now
+        if (SK_ScalarHalf*scaledStroke.fX > xRadius || SK_ScalarHalf*scaledStroke.fY > yRadius) {
+            return false;
+        }
+    }
+
+    // The way the effect interpolates the offset-to-ellipse/circle-center attribute only works on
+    // the interior of the rrect if the radii are >= 0.5. Otherwise, the inner rect of the nine-
+    // patch will have fractional coverage. This only matters when the interior is actually filled.
+    // We could consider falling back to rect rendering here, since a tiny radius is
+    // indistinguishable from a square corner.
+    if (!isStrokeOnly && (SK_ScalarHalf > xRadius || SK_ScalarHalf > yRadius)) {
         return false;
     }
 
     // reset to device coordinates
     GrDrawState* drawState = target->drawState();
     GrDrawState::AutoViewMatrixRestore avmr;
     if (!avmr.setIdentity(drawState)) {
         return false;
     }
 
-    bool isStroked = (SkStrokeRec::kStroke_Style == style || SkStrokeRec::kHairline_Style == style);
-
     GrIndexBuffer* indexBuffer = this->rRectIndexBuffer(context->getGpu());
     if (NULL == indexBuffer) {
         GrPrintf("Failed to create index buffer!\n");
         return false;
     }
 
     // if the corners are circles, use the circle renderer
-    if ((!isStroked || scaledStroke.fX == scaledStroke.fY) && xRadius == yRadius) {
+    if ((!hasStroke || scaledStroke.fX == scaledStroke.fY) && xRadius == yRadius) {
         drawState->setVertexAttribs<gCircleVertexAttribs>(SK_ARRAY_COUNT(gCircleVertexAttribs));
         SkASSERT(sizeof(CircleVertex) == drawState->getVertexSize());
 
         GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
         if (!geo.succeeded()) {
             GrPrintf("Failed to get space for vertices!\n");
             return false;
         }
         CircleVertex* verts = reinterpret_cast<CircleVertex*>(geo.vertices());
 
         SkScalar innerRadius = 0.0f;
         SkScalar outerRadius = xRadius;
         SkScalar halfWidth = 0;
-        if (style != SkStrokeRec::kFill_Style) {
+        if (hasStroke) {
             if (SkScalarNearlyZero(scaledStroke.fX)) {
                 halfWidth = SK_ScalarHalf;
             } else {
                 halfWidth = SkScalarHalf(scaledStroke.fX);
             }
 
-            if (isStroked) {
+            if (isStrokeOnly) {
                 innerRadius = xRadius - halfWidth;
             }
             outerRadius += halfWidth;
             bounds.outset(halfWidth, halfWidth);
         }
 
-        isStroked = (isStroked && innerRadius >= 0);
+        isStrokeOnly = (isStrokeOnly && innerRadius >= 0);
 
-        GrEffectRef* effect = CircleEdgeEffect::Create(isStroked);
+        GrEffectRef* effect = CircleEdgeEffect::Create(isStrokeOnly);
         static const int kCircleEdgeAttrIndex = 1;
         drawState->addCoverageEffect(effect, kCircleEdgeAttrIndex)->unref();
 
         // The radii are outset for two reasons. First, it allows the shader to simply perform
         // clamp(distance-to-center - radius, 0, 1). Second, the outer radius is used to compute the
         // verts of the bounding box that is rendered and the outset ensures the box will cover all
         // pixels partially covered by the circle.
         outerRadius += SK_ScalarHalf;
         innerRadius -= SK_ScalarHalf;
 
@@ skipping 32 matching lines @@
             verts++;
 
             verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
             verts->fOffset = SkPoint::Make(outerRadius, yOuterRadii[i]);
             verts->fOuterRadius = outerRadius;
             verts->fInnerRadius = innerRadius;
             verts++;
         }
 
         // drop out the middle quad if we're stroked
-        int indexCnt = isStroked ? SK_ARRAY_COUNT(gRRectIndices)-6 : SK_ARRAY_COUNT(gRRectIndices);
+        int indexCnt = isStrokeOnly ? SK_ARRAY_COUNT(gRRectIndices) - 6 :
+                                      SK_ARRAY_COUNT(gRRectIndices);
         target->setIndexSourceToBuffer(indexBuffer);
         target->drawIndexed(kTriangles_GrPrimitiveType, 0, 0, 16, indexCnt, &bounds);
 
     // otherwise we use the ellipse renderer
     } else {
         drawState->setVertexAttribs<gEllipseVertexAttribs>(SK_ARRAY_COUNT(gEllipseVertexAttribs));
         SkASSERT(sizeof(EllipseVertex) == drawState->getVertexSize());
 
         SkScalar innerXRadius = 0.0f;
         SkScalar innerYRadius = 0.0f;
-        if (SkStrokeRec::kFill_Style != style) {
+        if (hasStroke) {
             if (SkScalarNearlyZero(scaledStroke.length())) {
                 scaledStroke.set(SK_ScalarHalf, SK_ScalarHalf);
             } else {
                 scaledStroke.scale(SK_ScalarHalf);
             }
 
             // we only handle thick strokes for near-circular ellipses
             if (scaledStroke.length() > SK_ScalarHalf &&
                 (SK_ScalarHalf*xRadius > yRadius || SK_ScalarHalf*yRadius > xRadius)) {
                 return false;
             }
 
             // we don't handle it if curvature of the stroke is less than curvature of the ellipse
             if (scaledStroke.fX*(yRadius*yRadius) < (scaledStroke.fY*scaledStroke.fY)*xRadius ||
                 scaledStroke.fY*(xRadius*xRadius) < (scaledStroke.fX*scaledStroke.fX)*yRadius) {
                 return false;
             }
 
             // this is legit only if scale & translation (which should be the case at the moment)
-            if (isStroked) {
+            if (isStrokeOnly) {
                 innerXRadius = xRadius - scaledStroke.fX;
                 innerYRadius = yRadius - scaledStroke.fY;
             }
 
             xRadius += scaledStroke.fX;
             yRadius += scaledStroke.fY;
             bounds.outset(scaledStroke.fX, scaledStroke.fY);
         }
 
-        isStroked = (isStroked && innerXRadius >= 0 && innerYRadius >= 0);
+        isStrokeOnly = (isStrokeOnly && innerXRadius >= 0 && innerYRadius >= 0);
 
         GrDrawTarget::AutoReleaseGeometry geo(target, 16, 0);
         if (!geo.succeeded()) {
             GrPrintf("Failed to get space for vertices!\n");
             return false;
         }
         EllipseVertex* verts = reinterpret_cast<EllipseVertex*>(geo.vertices());
 
-        GrEffectRef* effect = EllipseEdgeEffect::Create(isStroked);
+        GrEffectRef* effect = EllipseEdgeEffect::Create(isStrokeOnly);
         static const int kEllipseOffsetAttrIndex = 1;
         static const int kEllipseRadiiAttrIndex = 2;
         drawState->addCoverageEffect(effect,
                                      kEllipseOffsetAttrIndex, kEllipseRadiiAttrIndex)->unref();
 
         // Compute the reciprocals of the radii here to save time in the shader
         SkScalar xRadRecip = SkScalarInvert(xRadius);
         SkScalar yRadRecip = SkScalarInvert(yRadius);
         SkScalar xInnerRadRecip = SkScalarInvert(innerXRadius);
         SkScalar yInnerRadRecip = SkScalarInvert(innerYRadius);
@@ skipping 38 matching lines @@
             verts++;
 
             verts->fPos = SkPoint::Make(bounds.fRight, yCoords[i]);
             verts->fOffset = SkPoint::Make(xOuterRadius, yOuterOffsets[i]);
             verts->fOuterRadii = SkPoint::Make(xRadRecip, yRadRecip);
             verts->fInnerRadii = SkPoint::Make(xInnerRadRecip, yInnerRadRecip);
             verts++;
         }
 
         // drop out the middle quad if we're stroked
-        int indexCnt = isStroked ? SK_ARRAY_COUNT(gRRectIndices)-6 : SK_ARRAY_COUNT(gRRectIndices);
+        int indexCnt = isStrokeOnly ? SK_ARRAY_COUNT(gRRectIndices) - 6 :
+                                      SK_ARRAY_COUNT(gRRectIndices);
         target->setIndexSourceToBuffer(indexBuffer);
         target->drawIndexed(kTriangles_GrPrimitiveType, 0, 0, 16, indexCnt, &bounds);
     }
 
     return true;
 }