1/*
2 * Copyright (C) 2010 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#include "Patch.h"
18
19#include "Caches.h"
20#include "Properties.h"
21#include "UvMapper.h"
22#include "utils/MathUtils.h"
23
24#include <algorithm>
25#include <utils/Log.h>
26
27namespace android {
28namespace uirenderer {
29
30///////////////////////////////////////////////////////////////////////////////
31// Vertices management
32///////////////////////////////////////////////////////////////////////////////
33
34uint32_t Patch::getSize() const {
35    return verticesCount * sizeof(TextureVertex);
36}
37
38Patch::Patch(const float bitmapWidth, const float bitmapHeight,
39        float width, float height, const UvMapper& mapper, const Res_png_9patch* patch)
40        : mColors(patch->getColors()) {
41
42    int8_t emptyQuads = 0;
43    const int8_t numColors = patch->numColors;
44    if (uint8_t(numColors) < sizeof(uint32_t) * 4) {
45        for (int8_t i = 0; i < numColors; i++) {
46            if (mColors[i] == 0x0) {
47                emptyQuads++;
48            }
49        }
50    }
51
52    hasEmptyQuads = emptyQuads > 0;
53
54    uint32_t xCount = patch->numXDivs;
55    uint32_t yCount = patch->numYDivs;
56
57    uint32_t maxVertices = ((xCount + 1) * (yCount + 1) - emptyQuads) * 4;
58    if (maxVertices == 0) return;
59
60    vertices.reset(new TextureVertex[maxVertices]);
61    TextureVertex* vertex = vertices.get();
62
63    const int32_t* xDivs = patch->getXDivs();
64    const int32_t* yDivs = patch->getYDivs();
65
66    const uint32_t xStretchCount = (xCount + 1) >> 1;
67    const uint32_t yStretchCount = (yCount + 1) >> 1;
68
69    float stretchX = 0.0f;
70    float stretchY = 0.0f;
71
72    float rescaleX = 1.0f;
73    float rescaleY = 1.0f;
74
75    if (xStretchCount > 0) {
76        uint32_t stretchSize = 0;
77        for (uint32_t i = 1; i < xCount; i += 2) {
78            stretchSize += xDivs[i] - xDivs[i - 1];
79        }
80        const float xStretchTex = stretchSize;
81        const float fixed = bitmapWidth - stretchSize;
82        const float xStretch = std::max(width - fixed, 0.0f);
83        stretchX = xStretch / xStretchTex;
84        rescaleX = fixed == 0.0f ? 0.0f : std::min(std::max(width, 0.0f) / fixed, 1.0f);
85    }
86
87    if (yStretchCount > 0) {
88        uint32_t stretchSize = 0;
89        for (uint32_t i = 1; i < yCount; i += 2) {
90            stretchSize += yDivs[i] - yDivs[i - 1];
91        }
92        const float yStretchTex = stretchSize;
93        const float fixed = bitmapHeight - stretchSize;
94        const float yStretch = std::max(height - fixed, 0.0f);
95        stretchY = yStretch / yStretchTex;
96        rescaleY = fixed == 0.0f ? 0.0f : std::min(std::max(height, 0.0f) / fixed, 1.0f);
97    }
98
99    uint32_t quadCount = 0;
100
101    float previousStepY = 0.0f;
102
103    float y1 = 0.0f;
104    float y2 = 0.0f;
105    float v1 = 0.0f;
106
107    mUvMapper = mapper;
108
109    for (uint32_t i = 0; i < yCount; i++) {
110        float stepY = yDivs[i];
111        const float segment = stepY - previousStepY;
112
113        if (i & 1) {
114            y2 = y1 + floorf(segment * stretchY + 0.5f);
115        } else {
116            y2 = y1 + segment * rescaleY;
117        }
118
119        float vOffset = y1 == y2 ? 0.0f : 0.5 - (0.5 * segment / (y2 - y1));
120        float v2 = std::max(0.0f, stepY - vOffset) / bitmapHeight;
121        v1 += vOffset / bitmapHeight;
122
123        if (stepY > 0.0f) {
124            generateRow(xDivs, xCount, vertex, y1, y2, v1, v2, stretchX, rescaleX,
125                    width, bitmapWidth, quadCount);
126        }
127
128        y1 = y2;
129        v1 = stepY / bitmapHeight;
130
131        previousStepY = stepY;
132    }
133
134    if (previousStepY != bitmapHeight) {
135        y2 = height;
136        generateRow(xDivs, xCount, vertex, y1, y2, v1, 1.0f, stretchX, rescaleX,
137                width, bitmapWidth, quadCount);
138    }
139
140    if (verticesCount != maxVertices) {
141        std::unique_ptr<TextureVertex[]> reducedVertices(new TextureVertex[verticesCount]);
142        memcpy(reducedVertices.get(), vertices.get(), verticesCount * sizeof(TextureVertex));
143        vertices = std::move(reducedVertices);
144    }
145}
146
147void Patch::generateRow(const int32_t* xDivs, uint32_t xCount, TextureVertex*& vertex,
148        float y1, float y2, float v1, float v2, float stretchX, float rescaleX,
149        float width, float bitmapWidth, uint32_t& quadCount) {
150    float previousStepX = 0.0f;
151
152    float x1 = 0.0f;
153    float x2 = 0.0f;
154    float u1 = 0.0f;
155
156    // Generate the row quad by quad
157    for (uint32_t i = 0; i < xCount; i++) {
158        float stepX = xDivs[i];
159        const float segment = stepX - previousStepX;
160
161        if (i & 1) {
162            x2 = x1 + floorf(segment * stretchX + 0.5f);
163        } else {
164            x2 = x1 + segment * rescaleX;
165        }
166
167        float uOffset = x1 == x2 ? 0.0f : 0.5 - (0.5 * segment / (x2 - x1));
168        float u2 = std::max(0.0f, stepX - uOffset) / bitmapWidth;
169        u1 += uOffset / bitmapWidth;
170
171        if (stepX > 0.0f) {
172            generateQuad(vertex, x1, y1, x2, y2, u1, v1, u2, v2, quadCount);
173        }
174
175        x1 = x2;
176        u1 = stepX / bitmapWidth;
177
178        previousStepX = stepX;
179    }
180
181    if (previousStepX != bitmapWidth) {
182        x2 = width;
183        generateQuad(vertex, x1, y1, x2, y2, u1, v1, 1.0f, v2, quadCount);
184    }
185}
186
187void Patch::generateQuad(TextureVertex*& vertex, float x1, float y1, float x2, float y2,
188            float u1, float v1, float u2, float v2, uint32_t& quadCount) {
189    const uint32_t oldQuadCount = quadCount;
190    quadCount++;
191
192    x1 = std::max(x1, 0.0f);
193    x2 = std::max(x2, 0.0f);
194    y1 = std::max(y1, 0.0f);
195    y2 = std::max(y2, 0.0f);
196
197    // Skip degenerate and transparent (empty) quads
198    if ((mColors[oldQuadCount] == 0) || x1 >= x2 || y1 >= y2) {
199#if DEBUG_PATCHES_EMPTY_VERTICES
200        PATCH_LOGD("    quad %d (empty)", oldQuadCount);
201        PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.8f, %.8f", x1, y1, u1, v1);
202        PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.8f, %.8f", x2, y2, u2, v2);
203#endif
204        return;
205    }
206
207    // Record all non empty quads
208    if (hasEmptyQuads) {
209        quads.emplace_back(x1, y1, x2, y2);
210    }
211
212    mUvMapper.map(u1, v1, u2, v2);
213
214    TextureVertex::set(vertex++, x1, y1, u1, v1);
215    TextureVertex::set(vertex++, x2, y1, u2, v1);
216    TextureVertex::set(vertex++, x1, y2, u1, v2);
217    TextureVertex::set(vertex++, x2, y2, u2, v2);
218
219    verticesCount += 4;
220    indexCount += 6;
221
222#if DEBUG_PATCHES_VERTICES
223    PATCH_LOGD("    quad %d", oldQuadCount);
224    PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.8f, %.8f", x1, y1, u1, v1);
225    PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.8f, %.8f", x2, y2, u2, v2);
226#endif
227}
228
229}; // namespace uirenderer
230}; // namespace android
231