OLD | NEW |
---|---|
1 /* | 1 /* |
2 * Copyright 2006 The Android Open Source Project | 2 * Copyright 2006 The Android Open Source Project |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 | 7 |
8 #ifndef SkCanvas_DEFINED | 8 #ifndef SkCanvas_DEFINED |
9 #define SkCanvas_DEFINED | 9 #define SkCanvas_DEFINED |
10 | 10 |
(...skipping 22 matching lines...) Expand all Loading... | |
33 class SkPath; | 33 class SkPath; |
34 class SkPicture; | 34 class SkPicture; |
35 class SkPixmap; | 35 class SkPixmap; |
36 class SkRasterClip; | 36 class SkRasterClip; |
37 class SkRRect; | 37 class SkRRect; |
38 struct SkRSXform; | 38 struct SkRSXform; |
39 class SkSurface; | 39 class SkSurface; |
40 class SkSurface_Base; | 40 class SkSurface_Base; |
41 class SkTextBlob; | 41 class SkTextBlob; |
42 | 42 |
43 /** \struct SkShadowParams | |
44 | |
45 This struct holds information needed for drawing shadows. | |
46 | |
47 fShadowRadius - radius of the shadow blur | |
48 | |
49 fBiasingConstant - A constant used in variance shadow mapping to directly | |
50 0.0 - 1.0 reduce light bleeding. Essentially sets all shadows | |
51 ~.25 below a certain brightness equal to no light, and does | |
52 a linear step on the rest. Essentially makes shadows | |
53 darker and more rounded at higher values. | |
54 | |
55 fMinVariance - Too low of a variance (near the outer edges of blurry | |
56 ~512, 1024 shadows) will lead to ugly sharp shadow brightness | |
57 distortions. This enforces a minimum amount of variance | |
58 in the calculation to smooth out the outside edges of | |
59 blurry shadows. However, too high of a value for this will | |
60 cause all shadows to be lighter by visibly different | |
61 amounts varying on depth. | |
62 | |
63 fShadowAlgorithm - Decides which algorithm to use to draw shadows. | |
64 */ | |
65 struct SkShadowParams { | |
66 SkScalar fShadowRadius; | |
67 SkScalar fBiasingConstant; | |
68 SkScalar fMinVariance; | |
69 | |
70 enum ShadowType { | |
71 kNoBlur_BlurAlgorithm, | |
72 kVariance_BlurAlgorithm | |
73 }; | |
74 ShadowType fType; | |
75 }; | |
76 | |
43 /** \class SkCanvas | 77 /** \class SkCanvas |
44 | 78 |
45 A Canvas encapsulates all of the state about drawing into a device (bitmap). | 79 A Canvas encapsulates all of the state about drawing into a device (bitmap). |
46 This includes a reference to the device itself, and a stack of matrix/clip | 80 This includes a reference to the device itself, and a stack of matrix/clip |
47 values. For any given draw call (e.g. drawRect), the geometry of the object | 81 values. For any given draw call (e.g. drawRect), the geometry of the object |
48 being drawn is transformed by the concatenation of all the matrices in the | 82 being drawn is transformed by the concatenation of all the matrices in the |
49 stack. The transformed geometry is clipped by the intersection of all of | 83 stack. The transformed geometry is clipped by the intersection of all of |
50 the clips in the stack. | 84 the clips in the stack. |
51 | 85 |
52 While the Canvas holds the state of the drawing device, the state (style) | 86 While the Canvas holds the state of the drawing device, the state (style) |
(...skipping 1013 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
1066 * This is logically equivalent to | 1100 * This is logically equivalent to |
1067 * saveLayer(paint)/drawPicture/restore | 1101 * saveLayer(paint)/drawPicture/restore |
1068 */ | 1102 */ |
1069 void drawPicture(const SkPicture*, const SkMatrix* matrix, const SkPaint* pa int); | 1103 void drawPicture(const SkPicture*, const SkMatrix* matrix, const SkPaint* pa int); |
1070 void drawPicture(const sk_sp<SkPicture>& picture, const SkMatrix* matrix, co nst SkPaint* paint) { | 1104 void drawPicture(const sk_sp<SkPicture>& picture, const SkMatrix* matrix, co nst SkPaint* paint) { |
1071 this->drawPicture(picture.get(), matrix, paint); | 1105 this->drawPicture(picture.get(), matrix, paint); |
1072 } | 1106 } |
1073 | 1107 |
1074 #ifdef SK_EXPERIMENTAL_SHADOWING | 1108 #ifdef SK_EXPERIMENTAL_SHADOWING |
1075 /** | 1109 /** |
1076 * Draw the picture into this canvas. | 1110 * Draw the picture into this canvas, with shadows! |
1077 * | 1111 * |
1078 * We will use the canvas's lights along with the picture information (draw depths of | 1112 * We will use the canvas's lights along with the picture information (draw depths of |
1079 * objects, etc) to first create a set of shadowmaps for the light-picture pairs, and | 1113 * objects, etc) to first create a set of shadowmaps for the light-picture pairs, and |
1080 * then use that set of shadowmaps to render the scene with shadows. | 1114 * then use that set of shadowmaps to render the scene with shadows. |
1081 * | 1115 * |
1082 * If matrix is non-null, apply that matrix to the CTM when drawing this pi cture. This is | 1116 * If matrix is non-null, apply that matrix to the CTM when drawing this pi cture. This is |
1083 * logically equivalent to | 1117 * logically equivalent to |
1084 * save/concat/drawPicture/restore | 1118 * save/concat/drawPicture/restore |
1085 * | 1119 * |
1086 * If paint is non-null, draw the picture into a temporary buffer, and then apply the paint's | 1120 * If paint is non-null, draw the picture into a temporary buffer, and then apply the paint's |
1087 * alpha/colorfilter/imagefilter/xfermode to that buffer as it is drawn to the canvas. | 1121 * alpha/colorfilter/imagefilter/xfermode to that buffer as it is drawn to the canvas. |
1088 * This is logically equivalent to | 1122 * This is logically equivalent to |
1089 * saveLayer(paint)/drawPicture/restore | 1123 * saveLayer(paint)/drawPicture/restore |
1090 * | 1124 * |
1125 * We also support using variance shadow maps for blurred shadows; the user can specify | |
robertphillips
2016/08/23 17:19:39
sType -> params
vjiaoblack
2016/08/23 18:01:21
Done.
| |
1126 * what shadow mapping algorithm to use with sType. | |
1127 * - Variance Shadow Mapping works by storing both the depth and depth^2 in the shadow map. | |
1128 * - Then, the shadow map can be blurred, and when reading from it, the f ragment shader | |
1129 * can calculate the variance of the depth at a position by doing E(x^2 ) - E(x)^2. | |
1130 * - We can then use the depth variance and depth at a fragment to arrive at an upper bound | |
1131 * of the probability that the current surface is shadowed by using Che byshev's | |
1132 * inequality, and then use that to shade the fragment. | |
1133 * | |
1134 * - There are a few problems with VSM. | |
1135 * * Light Bleeding | Areas with high variance, such as near the edges of high up rects, | |
1136 * will cause their shadow penumbras to overwrite ot herwise solid | |
1137 * shadows. | |
1138 * * Shape Distortion | We can combat Light Bleeding by biasing the sha dow (setting | |
1139 * mostly shaded fragments to completely shaded) a nd increasing | |
1140 * the minimum allowed variance. However, this war ps and rounds | |
1141 * out the shape of the shadow. | |
1091 */ | 1142 */ |
1092 void drawShadowedPicture(const SkPicture*, | 1143 void drawShadowedPicture(const SkPicture*, |
1093 const SkMatrix* matrix, | 1144 const SkMatrix* matrix, |
1094 const SkPaint* paint); | 1145 const SkPaint* paint, |
1146 const SkShadowParams& params); | |
1095 void drawShadowedPicture(const sk_sp<SkPicture>& picture, | 1147 void drawShadowedPicture(const sk_sp<SkPicture>& picture, |
1096 const SkMatrix* matrix, | 1148 const SkMatrix* matrix, |
1097 const SkPaint* paint) { | 1149 const SkPaint* paint, |
1098 this->drawShadowedPicture(picture.get(), matrix, paint); | 1150 const SkShadowParams& params) { |
1151 this->drawShadowedPicture(picture.get(), matrix, paint, params); | |
1099 } | 1152 } |
1100 #endif | 1153 #endif |
1101 | 1154 |
1102 enum VertexMode { | 1155 enum VertexMode { |
1103 kTriangles_VertexMode, | 1156 kTriangles_VertexMode, |
1104 kTriangleStrip_VertexMode, | 1157 kTriangleStrip_VertexMode, |
1105 kTriangleFan_VertexMode | 1158 kTriangleFan_VertexMode |
1106 }; | 1159 }; |
1107 | 1160 |
1108 /** Draw the array of vertices, interpreted as triangles (based on mode). | 1161 /** Draw the array of vertices, interpreted as triangles (based on mode). |
(...skipping 318 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
1427 virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle e dgeStyle); | 1480 virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle e dgeStyle); |
1428 virtual void onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op); | 1481 virtual void onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op); |
1429 | 1482 |
1430 virtual void onDiscard(); | 1483 virtual void onDiscard(); |
1431 | 1484 |
1432 virtual void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint* ); | 1485 virtual void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint* ); |
1433 | 1486 |
1434 #ifdef SK_EXPERIMENTAL_SHADOWING | 1487 #ifdef SK_EXPERIMENTAL_SHADOWING |
1435 virtual void onDrawShadowedPicture(const SkPicture*, | 1488 virtual void onDrawShadowedPicture(const SkPicture*, |
1436 const SkMatrix*, | 1489 const SkMatrix*, |
1437 const SkPaint*); | 1490 const SkPaint*, |
1491 const SkShadowParams& params); | |
1438 #endif | 1492 #endif |
1439 | 1493 |
1440 // Returns the canvas to be used by DrawIter. Default implementation | 1494 // Returns the canvas to be used by DrawIter. Default implementation |
1441 // returns this. Subclasses that encapsulate an indirect canvas may | 1495 // returns this. Subclasses that encapsulate an indirect canvas may |
1442 // need to overload this method. The impl must keep track of this, as it | 1496 // need to overload this method. The impl must keep track of this, as it |
1443 // is not released or deleted by the caller. | 1497 // is not released or deleted by the caller. |
1444 virtual SkCanvas* canvasForDrawIter(); | 1498 virtual SkCanvas* canvasForDrawIter(); |
1445 | 1499 |
1446 // Clip rectangle bounds. Called internally by saveLayer. | 1500 // Clip rectangle bounds. Called internally by saveLayer. |
1447 // returns false if the entire rectangle is entirely clipped out | 1501 // returns false if the entire rectangle is entirely clipped out |
(...skipping 238 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
1686 | 1740 |
1687 class SkCanvasClipVisitor { | 1741 class SkCanvasClipVisitor { |
1688 public: | 1742 public: |
1689 virtual ~SkCanvasClipVisitor(); | 1743 virtual ~SkCanvasClipVisitor(); |
1690 virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0; | 1744 virtual void clipRect(const SkRect&, SkRegion::Op, bool antialias) = 0; |
1691 virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0; | 1745 virtual void clipRRect(const SkRRect&, SkRegion::Op, bool antialias) = 0; |
1692 virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0; | 1746 virtual void clipPath(const SkPath&, SkRegion::Op, bool antialias) = 0; |
1693 }; | 1747 }; |
1694 | 1748 |
1695 #endif | 1749 #endif |
OLD | NEW |