commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2014 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | #ifndef GrConvexPolyEffect_DEFINED |
| 9 | #define GrConvexPolyEffect_DEFINED |
| 10 | |
| 11 | #include "GrDrawTargetCaps.h" |
| 12 | #include "GrEffect.h" |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 13 | #include "GrTypesPriv.h" |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 14 | |
| 15 | class GrGLConvexPolyEffect; |
| 16 | class SkPath; |
| 17 | |
| 18 | /** |
| 19 | * An effect that renders a convex polygon. It is intended to be used as a coverage effect. |
| 20 | * Bounding geometry is rendered and the effect computes coverage based on the fragment's |
| 21 | * position relative to the polygon. |
| 22 | */ |
| 23 | class GrConvexPolyEffect : public GrEffect { |
| 24 | public: |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 25 | enum { |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 26 | kMaxEdges = 8, |
| 27 | }; |
| 28 | |
| 29 | /** |
| 30 | * edges is a set of n edge equations where n is limited to kMaxEdges. It contains 3*n values. |
| 31 | * The edges should form a convex polygon. The positive half-plane is considered to be the |
| 32 | * inside. The equations should be normalized such that the first two coefficients are a unit |
| 33 | * 2d vector. |
| 34 | * |
| 35 | * Currently the edges are specified in device space. In the future we may prefer to specify |
| 36 | * them in src space. There are a number of ways this could be accomplished but we'd probably |
| 37 | * have to modify the effect/shaderbuilder interface to make it possible (e.g. give access |
| 38 | * to the view matrix or untransformed positions in the fragment shader). |
| 39 | */ |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 40 | static GrEffectRef* Create(GrEffectEdgeType edgeType, int n, const SkScalar edges[]) { |
| 41 | if (n <= 0 || n > kMaxEdges || kHairlineAA_GrEffectEdgeType == edgeType) { |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 42 | return NULL; |
| 43 | } |
| 44 | return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(GrConvexPolyEffect, |
| 45 | (edgeType, n, edges)))); |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * Creates an effect that clips against the path. If the path is not a convex polygon, is |
commit-bot@chromium.org | b21fac1 | 2014-02-07 21:13:11 +0000 | [diff] [blame] | 50 | * inverse filled, or has too many edges, this will return NULL. If offset is non-NULL, then |
| 51 | * the path is translated by the vector. |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 52 | */ |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 53 | static GrEffectRef* Create(GrEffectEdgeType, const SkPath&, const SkVector* offset = NULL); |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 54 | |
commit-bot@chromium.org | f053980 | 2014-02-08 19:31:05 +0000 | [diff] [blame] | 55 | /** |
| 56 | * Creates an effect that fills inside the rect with AA edges.. |
| 57 | */ |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 58 | static GrEffectRef* Create(GrEffectEdgeType, const SkRect&); |
commit-bot@chromium.org | f053980 | 2014-02-08 19:31:05 +0000 | [diff] [blame] | 59 | |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 60 | virtual ~GrConvexPolyEffect(); |
| 61 | |
| 62 | static const char* Name() { return "ConvexPoly"; } |
| 63 | |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 64 | GrEffectEdgeType getEdgeType() const { return fEdgeType; } |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 65 | |
| 66 | int getEdgeCount() const { return fEdgeCount; } |
| 67 | |
| 68 | const SkScalar* getEdges() const { return fEdges; } |
| 69 | |
| 70 | typedef GrGLConvexPolyEffect GLEffect; |
| 71 | |
| 72 | virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE; |
| 73 | |
| 74 | virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE; |
| 75 | |
| 76 | private: |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 77 | GrConvexPolyEffect(GrEffectEdgeType edgeType, int n, const SkScalar edges[]); |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 78 | |
| 79 | virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE; |
| 80 | |
commit-bot@chromium.org | cabf4b2 | 2014-03-05 18:27:43 +0000 | [diff] [blame^] | 81 | GrEffectEdgeType fEdgeType; |
| 82 | int fEdgeCount; |
| 83 | SkScalar fEdges[3 * kMaxEdges]; |
commit-bot@chromium.org | c3fe549 | 2014-01-30 18:15:51 +0000 | [diff] [blame] | 84 | |
| 85 | GR_DECLARE_EFFECT_TEST; |
| 86 | |
| 87 | typedef GrEffect INHERITED; |
| 88 | }; |
| 89 | |
| 90 | |
| 91 | #endif |