Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2012 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #ifndef ANDROID_HWUI_PATH_TESSELLATOR_H |
| 18 | #define ANDROID_HWUI_PATH_TESSELLATOR_H |
| 19 | |
| 20 | #include <utils/Vector.h> |
| 21 | |
| 22 | #include "Matrix.h" |
| 23 | #include "Rect.h" |
| 24 | #include "Vertex.h" |
ztenghui | 55bfb4e | 2013-12-03 10:38:55 -0800 | [diff] [blame] | 25 | #include "VertexBuffer.h" |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 26 | |
| 27 | namespace android { |
| 28 | namespace uirenderer { |
| 29 | |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 30 | class PathTessellator { |
| 31 | public: |
Chris Craik | f0a5907 | 2013-11-19 18:00:46 -0800 | [diff] [blame] | 32 | static void expandBoundsForStroke(SkRect& bounds, const SkPaint* paint); |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 33 | |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 34 | /** |
| 35 | * Populates a VertexBuffer with a tessellated approximation of the input convex path, as a single |
| 36 | * triangle strip. Note: joins are not currently supported. |
| 37 | * |
| 38 | * @param path The path to be approximated |
| 39 | * @param paint The paint the path will be drawn with, indicating AA, painting style |
| 40 | * (stroke vs fill), stroke width, stroke cap & join style, etc. |
| 41 | * @param transform The transform the path is to be drawn with, used to drive stretch-aware path |
| 42 | * vertex approximation, and correct AA ramp offsetting. |
| 43 | * @param vertexBuffer The output buffer |
| 44 | */ |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 45 | static void tessellatePath(const SkPath& path, const SkPaint* paint, |
Chris Craik | d6b65f6 | 2014-01-01 14:45:21 -0800 | [diff] [blame] | 46 | const mat4& transform, VertexBuffer& vertexBuffer); |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 47 | |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 48 | /** |
| 49 | * Populates a VertexBuffer with a tessellated approximation of points as a single triangle |
| 50 | * strip (with degenerate tris separating), respecting the shape defined by the paint cap. |
| 51 | * |
| 52 | * @param points The center vertices of the points to be drawn |
| 53 | * @param count The number of floats making up the point vertices |
| 54 | * @param paint The paint the points will be drawn with indicating AA, stroke width & cap |
| 55 | * @param transform The transform the points will be drawn with, used to drive stretch-aware path |
| 56 | * vertex approximation, and correct AA ramp offsetting |
| 57 | * @param bounds An output rectangle, which returns the total area covered by the output buffer |
| 58 | * @param vertexBuffer The output buffer |
| 59 | */ |
Chris Craik | d218a92 | 2014-01-02 17:13:34 -0800 | [diff] [blame] | 60 | static void tessellatePoints(const float* points, int count, const SkPaint* paint, |
Chris Craik | d6b65f6 | 2014-01-01 14:45:21 -0800 | [diff] [blame] | 61 | const mat4& transform, SkRect& bounds, VertexBuffer& vertexBuffer); |
Chris Craik | 6d29c8d | 2013-05-08 18:35:44 -0700 | [diff] [blame] | 62 | |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 63 | /** |
| 64 | * Populates a VertexBuffer with a tessellated approximation of lines as a single triangle |
| 65 | * strip (with degenerate tris separating). |
| 66 | * |
| 67 | * @param points Pairs of endpoints defining the lines to be drawn |
| 68 | * @param count The number of floats making up the line vertices |
| 69 | * @param paint The paint the lines will be drawn with indicating AA, stroke width & cap |
| 70 | * @param transform The transform the points will be drawn with, used to drive stretch-aware path |
| 71 | * vertex approximation, and correct AA ramp offsetting |
| 72 | * @param bounds An output rectangle, which returns the total area covered by the output buffer |
| 73 | * @param vertexBuffer The output buffer |
| 74 | */ |
Chris Craik | d218a92 | 2014-01-02 17:13:34 -0800 | [diff] [blame] | 75 | static void tessellateLines(const float* points, int count, const SkPaint* paint, |
Chris Craik | d6b65f6 | 2014-01-01 14:45:21 -0800 | [diff] [blame] | 76 | const mat4& transform, SkRect& bounds, VertexBuffer& vertexBuffer); |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 77 | |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 78 | /** |
| 79 | * Approximates a convex, CW outline into a Vector of 2d vertices. |
| 80 | * |
| 81 | * @param path The outline to be approximated |
| 82 | * @param thresholdSquared The threshold of acceptable error (in pixels) when approximating |
| 83 | * @param outputVertices An empty Vector which will be populated with the output |
| 84 | */ |
| 85 | static bool approximatePathOutlineVertices(const SkPath &path, float thresholdSquared, |
| 86 | Vector<Vertex> &outputVertices); |
| 87 | |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 88 | private: |
| 89 | static bool approximatePathOutlineVertices(const SkPath &path, bool forceClose, |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 90 | float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared, |
| 91 | Vector<Vertex> &outputVertices); |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 92 | |
| 93 | /* |
| 94 | endpoints a & b, |
| 95 | control c |
| 96 | */ |
| 97 | static void recursiveQuadraticBezierVertices( |
| 98 | float ax, float ay, |
| 99 | float bx, float by, |
| 100 | float cx, float cy, |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 101 | float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared, |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 102 | Vector<Vertex> &outputVertices); |
| 103 | |
| 104 | /* |
| 105 | endpoints p1, p2 |
| 106 | control c1, c2 |
| 107 | */ |
| 108 | static void recursiveCubicBezierVertices( |
| 109 | float p1x, float p1y, |
| 110 | float c1x, float c1y, |
| 111 | float p2x, float p2y, |
| 112 | float c2x, float c2y, |
Chris Craik | 15a07a2 | 2014-01-26 13:43:53 -0800 | [diff] [blame^] | 113 | float sqrInvScaleX, float sqrInvScaleY, float thresholdSquared, |
Chris Craik | 65cd612 | 2012-12-10 17:56:27 -0800 | [diff] [blame] | 114 | Vector<Vertex> &outputVertices); |
| 115 | }; |
| 116 | |
| 117 | }; // namespace uirenderer |
| 118 | }; // namespace android |
| 119 | |
| 120 | #endif // ANDROID_HWUI_PATH_TESSELLATOR_H |