Home | History | Annotate | Download | only in AndroidPathRenderer 
      1 
      2 /*
      3  * Copyright 2012 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 #include "GrAndroidPathRenderer.h"
     10 #include "AndroidPathRenderer.h"
     11 #include "Vertex.h"
     12 
     13 GrAndroidPathRenderer::GrAndroidPathRenderer() {
     14 }
     15 
     16 bool GrAndroidPathRenderer::canDrawPath(const SkPath& path,
     17                                         const SkStrokeRec& stroke,
     18                                         const GrDrawTarget* target,
     19                                         bool antiAlias) const {
     20     return ((stroke.isFillStyle() || stroke.getStyle() == SkStrokeRec::kStroke_Style)
     21              && !path.isInverseFillType() && path.isConvex());
     22 }
     23 
     24 struct ColorVertex {
     25     SkPoint pos;
     26     GrColor color;
     27 };
     28 
     29 bool GrAndroidPathRenderer::onDrawPath(const SkPath& origPath,
     30                                        const SkStrokeRec& stroke,
     31                                        GrDrawTarget* target,
     32                                        bool antiAlias) {
     33 
     34     // generate verts using Android algorithm
     35     android::uirenderer::VertexBuffer vertices;
     36     android::uirenderer::PathRenderer::ConvexPathVertices(origPath, stroke, antiAlias, NULL,
     37                                                           &vertices);
     38 
     39     // set vertex attributes depending on anti-alias
     40     GrDrawState* drawState = target->drawState();
     41     if (antiAlias) {
     42         // position + coverage
     43         GrVertexAttrib attribs[] = {
     44             GrVertexAttrib(kVec2f_GrVertexAttribType, 0),
     45             GrVertexAttrib(kVec4ub_GrVertexAttribType, sizeof(GrPoint))
     46         };
     47         drawState->setVertexAttribs(attribs, SK_ARRAY_COUNT(attribs));
     48         drawState->setAttribIndex(GrDrawState::kPosition_AttribIndex, 0);
     49         drawState->setAttribIndex(GrDrawState::kCoverage_AttribIndex, 1);
     50         drawState->setAttribBindings(GrDrawState::kCoverage_AttribBindingsBit);
     51     } else {
     52         drawState->setDefaultVertexAttribs();
     53     }
     54 
     55     // allocate our vert buffer
     56     int vertCount = vertices.getSize();
     57     GrDrawTarget::AutoReleaseGeometry geo(target, vertCount, 0);
     58     if (!geo.succeeded()) {
     59         SkDebugf("Failed to get space for vertices!\n");
     60         return false;
     61     }
     62 
     63     // copy android verts to our vertex buffer
     64     if (antiAlias) {
     65         SkASSERT(sizeof(ColorVertex) == drawState->getVertexSize());
     66         ColorVertex* outVert = reinterpret_cast<ColorVertex*>(geo.vertices());
     67         android::uirenderer::AlphaVertex* inVert =
     68             reinterpret_cast<android::uirenderer::AlphaVertex*>(vertices.getBuffer());
     69 
     70         for (int i = 0; i < vertCount; ++i) {
     71             // copy vertex position
     72             outVert->pos.set(inVert->position[0], inVert->position[1]);
     73             // copy alpha
     74             int coverage = static_cast<int>(inVert->alpha * 0xff);
     75             outVert->color = GrColorPackRGBA(coverage, coverage, coverage, coverage);
     76             ++outVert;
     77             ++inVert;
     78         }
     79     } else {
     80        size_t vsize = drawState->getVertexSize();
     81        size_t copySize = vsize*vertCount;
     82        memcpy(geo.vertices(), vertices.getBuffer(), copySize);
     83     }
     84 
     85     // render it
     86     target->drawNonIndexed(kTriangleStrip_GrPrimitiveType, 0, vertCount);
     87 
     88     return true;
     89 }
     90