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" |
| 25 | |
| 26 | namespace android { |
| 27 | namespace uirenderer { |
| 28 | |
| 29 | class VertexBuffer { |
| 30 | public: |
| 31 | VertexBuffer(): |
| 32 | mBuffer(0), |
| 33 | mSize(0), |
| 34 | mCleanupMethod(NULL) |
| 35 | {} |
| 36 | |
| 37 | ~VertexBuffer() { |
| 38 | if (mCleanupMethod) mCleanupMethod(mBuffer); |
| 39 | } |
| 40 | |
| 41 | /** |
| 42 | This should be the only method used by the PathTessellator. Subsequent calls to alloc will |
| 43 | allocate space within the first allocation (useful if you want to eventually allocate |
| 44 | multiple regions within a single VertexBuffer, such as with PathTessellator::tesselateLines() |
| 45 | */ |
| 46 | template <class TYPE> |
| 47 | TYPE* alloc(int size) { |
| 48 | if (mSize) { |
| 49 | TYPE* reallocBuffer = (TYPE*)mReallocBuffer; |
| 50 | // already have allocated the buffer, re-allocate space within |
| 51 | if (mReallocBuffer != mBuffer) { |
| 52 | // not first re-allocation, leave space for degenerate triangles to separate strips |
| 53 | reallocBuffer += 2; |
| 54 | } |
| 55 | mReallocBuffer = reallocBuffer + size; |
| 56 | return reallocBuffer; |
| 57 | } |
| 58 | mSize = size; |
| 59 | mReallocBuffer = mBuffer = (void*)new TYPE[size]; |
| 60 | mCleanupMethod = &(cleanup<TYPE>); |
| 61 | |
| 62 | return (TYPE*)mBuffer; |
| 63 | } |
| 64 | |
| 65 | void* getBuffer() const { return mBuffer; } |
| 66 | unsigned int getSize() const { return mSize; } |
| 67 | |
| 68 | template <class TYPE> |
| 69 | void createDegenerateSeparators(int allocSize) { |
| 70 | TYPE* end = (TYPE*)mBuffer + mSize; |
| 71 | for (TYPE* degen = (TYPE*)mBuffer + allocSize; degen < end; degen += 2 + allocSize) { |
| 72 | memcpy(degen, degen - 1, sizeof(TYPE)); |
| 73 | memcpy(degen + 1, degen + 2, sizeof(TYPE)); |
| 74 | } |
| 75 | } |
| 76 | |
| 77 | private: |
| 78 | template <class TYPE> |
| 79 | static void cleanup(void* buffer) { |
| 80 | delete[] (TYPE*)buffer; |
| 81 | } |
| 82 | |
| 83 | void* mBuffer; |
| 84 | unsigned int mSize; |
| 85 | |
| 86 | void* mReallocBuffer; // used for multi-allocation |
| 87 | |
| 88 | void (*mCleanupMethod)(void*); |
| 89 | }; |
| 90 | |
| 91 | class PathTessellator { |
| 92 | public: |
| 93 | static void expandBoundsForStroke(SkRect& bounds, const SkPaint* paint, bool forceExpand); |
| 94 | |
| 95 | static void tessellatePath(const SkPath& path, const SkPaint* paint, |
| 96 | const mat4 *transform, VertexBuffer& vertexBuffer); |
| 97 | |
| 98 | static void tessellateLines(const float* points, int count, SkPaint* paint, |
| 99 | const mat4* transform, SkRect& bounds, VertexBuffer& vertexBuffer); |
| 100 | |
| 101 | private: |
| 102 | static bool approximatePathOutlineVertices(const SkPath &path, bool forceClose, |
| 103 | float sqrInvScaleX, float sqrInvScaleY, Vector<Vertex> &outputVertices); |
| 104 | |
| 105 | /* |
| 106 | endpoints a & b, |
| 107 | control c |
| 108 | */ |
| 109 | static void recursiveQuadraticBezierVertices( |
| 110 | float ax, float ay, |
| 111 | float bx, float by, |
| 112 | float cx, float cy, |
| 113 | float sqrInvScaleX, float sqrInvScaleY, |
| 114 | Vector<Vertex> &outputVertices); |
| 115 | |
| 116 | /* |
| 117 | endpoints p1, p2 |
| 118 | control c1, c2 |
| 119 | */ |
| 120 | static void recursiveCubicBezierVertices( |
| 121 | float p1x, float p1y, |
| 122 | float c1x, float c1y, |
| 123 | float p2x, float p2y, |
| 124 | float c2x, float c2y, |
| 125 | float sqrInvScaleX, float sqrInvScaleY, |
| 126 | Vector<Vertex> &outputVertices); |
| 127 | }; |
| 128 | |
| 129 | }; // namespace uirenderer |
| 130 | }; // namespace android |
| 131 | |
| 132 | #endif // ANDROID_HWUI_PATH_TESSELLATOR_H |