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author | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2014-01-30 18:15:51 +0000 |
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committer | commit-bot@chromium.org <commit-bot@chromium.org@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2014-01-30 18:15:51 +0000 |
commit | c3fe54975daf6274103bcfefe5ed2e7af8d0170a (patch) | |
tree | 3f6fd520608519d149f203f9c089ab846e16eb7a /src/gpu/effects/GrConvexPolyEffect.h | |
parent | fd191a135ff2a945edf2d4ead602b795631b200f (diff) |
Add convex polygon rendering effect and GM to test it.
BUG=skia:2051
R=robertphillips@google.com, jvanverth@google.com
Author: bsalomon@google.com
Review URL: https://codereview.chromium.org/149683004
git-svn-id: http://skia.googlecode.com/svn/trunk@13242 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/gpu/effects/GrConvexPolyEffect.h')
-rw-r--r-- | src/gpu/effects/GrConvexPolyEffect.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/gpu/effects/GrConvexPolyEffect.h b/src/gpu/effects/GrConvexPolyEffect.h new file mode 100644 index 0000000000..8390e149b7 --- /dev/null +++ b/src/gpu/effects/GrConvexPolyEffect.h @@ -0,0 +1,95 @@ +/* + * Copyright 2014 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef GrConvexPolyEffect_DEFINED +#define GrConvexPolyEffect_DEFINED + +#include "GrDrawTargetCaps.h" +#include "GrEffect.h" +#include "GrVertexEffect.h" + +class GrGLConvexPolyEffect; +class SkPath; + +/** + * An effect that renders a convex polygon. It is intended to be used as a coverage effect. + * Bounding geometry is rendered and the effect computes coverage based on the fragment's + * position relative to the polygon. + */ +class GrConvexPolyEffect : public GrEffect { +public: + /** This could be expanded to include a AA hairline mode. If so, unify with GrBezierEffect's + enum. */ + enum EdgeType { + kFillNoAA_EdgeType, + kFillAA_EdgeType, + + kLastEdgeType = kFillAA_EdgeType, + }; + + enum { + kEdgeTypeCnt = kLastEdgeType + 1, + kMaxEdges = 8, + }; + + /** + * edges is a set of n edge equations where n is limited to kMaxEdges. It contains 3*n values. + * The edges should form a convex polygon. The positive half-plane is considered to be the + * inside. The equations should be normalized such that the first two coefficients are a unit + * 2d vector. + * + * Currently the edges are specified in device space. In the future we may prefer to specify + * them in src space. There are a number of ways this could be accomplished but we'd probably + * have to modify the effect/shaderbuilder interface to make it possible (e.g. give access + * to the view matrix or untransformed positions in the fragment shader). + */ + static GrEffectRef* Create(EdgeType edgeType, int n, const SkScalar edges[]) { + if (n <= 0 || n > kMaxEdges) { + return NULL; + } + return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(GrConvexPolyEffect, + (edgeType, n, edges)))); + } + + /** + * Creates an effect that clips against the path. If the path is not a convex polygon, is + * inverse filled, or has too many edges, this will return NULL. + */ + static GrEffectRef* Create(EdgeType, const SkPath&); + + virtual ~GrConvexPolyEffect(); + + static const char* Name() { return "ConvexPoly"; } + + EdgeType getEdgeType() const { return fEdgeType; } + + int getEdgeCount() const { return fEdgeCount; } + + const SkScalar* getEdges() const { return fEdges; } + + typedef GrGLConvexPolyEffect GLEffect; + + virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE; + + virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE; + +private: + GrConvexPolyEffect(EdgeType edgeType, int n, const SkScalar edges[]); + + virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE; + + EdgeType fEdgeType; + int fEdgeCount; + SkScalar fEdges[3 * kMaxEdges]; + + GR_DECLARE_EFFECT_TEST; + + typedef GrEffect INHERITED; +}; + + +#endif |