VertexBuffer.h revision 05f3d6e5111fd08df5cd9aae2c3d28399dc0e7f5 
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_VERTEX_BUFFER_H
18#define ANDROID_HWUI_VERTEX_BUFFER_H
19
20
21namespace android {
22namespace uirenderer {
23
24class VertexBuffer {
25public:
26    enum Mode {
27        kStandard = 0,
28        kOnePolyRingShadow = 1,
29        kTwoPolyRingShadow = 2
30    };
31
32    VertexBuffer()
33            : mBuffer(0)
34            , mVertexCount(0)
35            , mByteCount(0)
36            , mMode(kStandard)
37            , mCleanupMethod(NULL)
38    {}
39
40    ~VertexBuffer() {
41        if (mCleanupMethod) mCleanupMethod(mBuffer);
42    }
43
44    /**
45       This should be the only method used by the Tessellator. Subsequent calls to
46       alloc will allocate space within the first allocation (useful if you want to
47       eventually allocate multiple regions within a single VertexBuffer, such as
48       with PathTessellator::tessellateLines())
49     */
50    template <class TYPE>
51    TYPE* alloc(int vertexCount) {
52        if (mVertexCount) {
53            TYPE* reallocBuffer = (TYPE*)mReallocBuffer;
54            // already have allocated the buffer, re-allocate space within
55            if (mReallocBuffer != mBuffer) {
56                // not first re-allocation, leave space for degenerate triangles to separate strips
57                reallocBuffer += 2;
58            }
59            mReallocBuffer = reallocBuffer + vertexCount;
60            return reallocBuffer;
61        }
62        mVertexCount = vertexCount;
63        mByteCount = mVertexCount * sizeof(TYPE);
64        mReallocBuffer = mBuffer = (void*)new TYPE[vertexCount];
65        mCleanupMethod = &(cleanup<TYPE>);
66
67        return (TYPE*)mBuffer;
68    }
69
70    template <class TYPE>
71    void copyInto(const VertexBuffer& srcBuffer, float xOffset, float yOffset) {
72        int verticesToCopy = srcBuffer.getVertexCount();
73
74        TYPE* dst = alloc<TYPE>(verticesToCopy);
75        TYPE* src = (TYPE*)srcBuffer.getBuffer();
76
77        for (int i = 0; i < verticesToCopy; i++) {
78            TYPE::copyWithOffset(&dst[i], src[i], xOffset, yOffset);
79        }
80    }
81
82    const void* getBuffer() const { return mBuffer; }
83    const Rect& getBounds() const { return mBounds; }
84    unsigned int getVertexCount() const { return mVertexCount; }
85    unsigned int getSize() const { return mByteCount; }
86    Mode getMode() const { return mMode; }
87
88    void setBounds(Rect bounds) { mBounds = bounds; }
89    void setMode(Mode mode) { mMode = mode; }
90
91    template <class TYPE>
92    void createDegenerateSeparators(int allocSize) {
93        TYPE* end = (TYPE*)mBuffer + mVertexCount;
94        for (TYPE* degen = (TYPE*)mBuffer + allocSize; degen < end; degen += 2 + allocSize) {
95            memcpy(degen, degen - 1, sizeof(TYPE));
96            memcpy(degen + 1, degen + 2, sizeof(TYPE));
97        }
98    }
99
100private:
101    template <class TYPE>
102    static void cleanup(void* buffer) {
103        delete[] (TYPE*)buffer;
104    }
105
106    Rect mBounds;
107    void* mBuffer;
108    unsigned int mVertexCount;
109    unsigned int mByteCount;
110    Mode mMode;
111
112    void* mReallocBuffer; // used for multi-allocation
113
114    void (*mCleanupMethod)(void*);
115};
116
117}; // namespace uirenderer
118}; // namespace android
119
120#endif // ANDROID_HWUI_VERTEX_BUFFER_H
121