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 #define LOG_TAG "OpenGLRenderer"
18 
19 #include <cmath>
20 
21 #include <utils/Log.h>
22 
23 #include "Caches.h"
24 #include "Patch.h"
25 #include "Properties.h"
26 #include "UvMapper.h"
27 #include "utils/MathUtils.h"
28 
29 namespace android {
30 namespace uirenderer {
31 
32 ///////////////////////////////////////////////////////////////////////////////
33 // Vertices management
34 ///////////////////////////////////////////////////////////////////////////////
35 
getSize() const36 uint32_t Patch::getSize() const {
37     return verticesCount * sizeof(TextureVertex);
38 }
39 
Patch(const float bitmapWidth,const float bitmapHeight,float width,float height,const UvMapper & mapper,const Res_png_9patch * patch)40 Patch::Patch(const float bitmapWidth, const float bitmapHeight,
41         float width, float height, const UvMapper& mapper, const Res_png_9patch* patch)
42         : mColors(patch->getColors()) {
43 
44     int8_t emptyQuads = 0;
45     const int8_t numColors = patch->numColors;
46     if (uint8_t(numColors) < sizeof(uint32_t) * 4) {
47         for (int8_t i = 0; i < numColors; i++) {
48             if (mColors[i] == 0x0) {
49                 emptyQuads++;
50             }
51         }
52     }
53 
54     hasEmptyQuads = emptyQuads > 0;
55 
56     uint32_t xCount = patch->numXDivs;
57     uint32_t yCount = patch->numYDivs;
58 
59     uint32_t maxVertices = ((xCount + 1) * (yCount + 1) - emptyQuads) * 4;
60     if (maxVertices == 0) return;
61 
62     vertices.reset(new TextureVertex[maxVertices]);
63     TextureVertex* vertex = vertices.get();
64 
65     const int32_t* xDivs = patch->getXDivs();
66     const int32_t* yDivs = patch->getYDivs();
67 
68     const uint32_t xStretchCount = (xCount + 1) >> 1;
69     const uint32_t yStretchCount = (yCount + 1) >> 1;
70 
71     float stretchX = 0.0f;
72     float stretchY = 0.0f;
73 
74     float rescaleX = 1.0f;
75     float rescaleY = 1.0f;
76 
77     if (xStretchCount > 0) {
78         uint32_t stretchSize = 0;
79         for (uint32_t i = 1; i < xCount; i += 2) {
80             stretchSize += xDivs[i] - xDivs[i - 1];
81         }
82         const float xStretchTex = stretchSize;
83         const float fixed = bitmapWidth - stretchSize;
84         const float xStretch = std::max(width - fixed, 0.0f);
85         stretchX = xStretch / xStretchTex;
86         rescaleX = fixed == 0.0f ? 0.0f : std::min(std::max(width, 0.0f) / fixed, 1.0f);
87     }
88 
89     if (yStretchCount > 0) {
90         uint32_t stretchSize = 0;
91         for (uint32_t i = 1; i < yCount; i += 2) {
92             stretchSize += yDivs[i] - yDivs[i - 1];
93         }
94         const float yStretchTex = stretchSize;
95         const float fixed = bitmapHeight - stretchSize;
96         const float yStretch = std::max(height - fixed, 0.0f);
97         stretchY = yStretch / yStretchTex;
98         rescaleY = fixed == 0.0f ? 0.0f : std::min(std::max(height, 0.0f) / fixed, 1.0f);
99     }
100 
101     uint32_t quadCount = 0;
102 
103     float previousStepY = 0.0f;
104 
105     float y1 = 0.0f;
106     float y2 = 0.0f;
107     float v1 = 0.0f;
108 
109     mUvMapper = mapper;
110 
111     for (uint32_t i = 0; i < yCount; i++) {
112         float stepY = yDivs[i];
113         const float segment = stepY - previousStepY;
114 
115         if (i & 1) {
116             y2 = y1 + floorf(segment * stretchY + 0.5f);
117         } else {
118             y2 = y1 + segment * rescaleY;
119         }
120 
121         float vOffset = y1 == y2 ? 0.0f : 0.5 - (0.5 * segment / (y2 - y1));
122         float v2 = std::max(0.0f, stepY - vOffset) / bitmapHeight;
123         v1 += vOffset / bitmapHeight;
124 
125         if (stepY > 0.0f) {
126             generateRow(xDivs, xCount, vertex, y1, y2, v1, v2, stretchX, rescaleX,
127                     width, bitmapWidth, quadCount);
128         }
129 
130         y1 = y2;
131         v1 = stepY / bitmapHeight;
132 
133         previousStepY = stepY;
134     }
135 
136     if (previousStepY != bitmapHeight) {
137         y2 = height;
138         generateRow(xDivs, xCount, vertex, y1, y2, v1, 1.0f, stretchX, rescaleX,
139                 width, bitmapWidth, quadCount);
140     }
141 
142     if (verticesCount != maxVertices) {
143         std::unique_ptr<TextureVertex[]> reducedVertices(new TextureVertex[verticesCount]);
144         memcpy(reducedVertices.get(), vertices.get(), verticesCount * sizeof(TextureVertex));
145         vertices = std::move(reducedVertices);
146     }
147 }
148 
generateRow(const int32_t * xDivs,uint32_t xCount,TextureVertex * & vertex,float y1,float y2,float v1,float v2,float stretchX,float rescaleX,float width,float bitmapWidth,uint32_t & quadCount)149 void Patch::generateRow(const int32_t* xDivs, uint32_t xCount, TextureVertex*& vertex,
150         float y1, float y2, float v1, float v2, float stretchX, float rescaleX,
151         float width, float bitmapWidth, uint32_t& quadCount) {
152     float previousStepX = 0.0f;
153 
154     float x1 = 0.0f;
155     float x2 = 0.0f;
156     float u1 = 0.0f;
157 
158     // Generate the row quad by quad
159     for (uint32_t i = 0; i < xCount; i++) {
160         float stepX = xDivs[i];
161         const float segment = stepX - previousStepX;
162 
163         if (i & 1) {
164             x2 = x1 + floorf(segment * stretchX + 0.5f);
165         } else {
166             x2 = x1 + segment * rescaleX;
167         }
168 
169         float uOffset = x1 == x2 ? 0.0f : 0.5 - (0.5 * segment / (x2 - x1));
170         float u2 = std::max(0.0f, stepX - uOffset) / bitmapWidth;
171         u1 += uOffset / bitmapWidth;
172 
173         if (stepX > 0.0f) {
174             generateQuad(vertex, x1, y1, x2, y2, u1, v1, u2, v2, quadCount);
175         }
176 
177         x1 = x2;
178         u1 = stepX / bitmapWidth;
179 
180         previousStepX = stepX;
181     }
182 
183     if (previousStepX != bitmapWidth) {
184         x2 = width;
185         generateQuad(vertex, x1, y1, x2, y2, u1, v1, 1.0f, v2, quadCount);
186     }
187 }
188 
generateQuad(TextureVertex * & vertex,float x1,float y1,float x2,float y2,float u1,float v1,float u2,float v2,uint32_t & quadCount)189 void Patch::generateQuad(TextureVertex*& vertex, float x1, float y1, float x2, float y2,
190             float u1, float v1, float u2, float v2, uint32_t& quadCount) {
191     const uint32_t oldQuadCount = quadCount;
192     quadCount++;
193 
194     x1 = MathUtils::max(x1, 0.0f);
195     x2 = MathUtils::max(x2, 0.0f);
196     y1 = MathUtils::max(y1, 0.0f);
197     y2 = MathUtils::max(y2, 0.0f);
198 
199     // Skip degenerate and transparent (empty) quads
200     if ((mColors[oldQuadCount] == 0) || x1 >= x2 || y1 >= y2) {
201 #if DEBUG_PATCHES_EMPTY_VERTICES
202         PATCH_LOGD("    quad %d (empty)", oldQuadCount);
203         PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.8f, %.8f", x1, y1, u1, v1);
204         PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.8f, %.8f", x2, y2, u2, v2);
205 #endif
206         return;
207     }
208 
209     // Record all non empty quads
210     if (hasEmptyQuads) {
211         Rect bounds(x1, y1, x2, y2);
212         quads.add(bounds);
213     }
214 
215     mUvMapper.map(u1, v1, u2, v2);
216 
217     TextureVertex::set(vertex++, x1, y1, u1, v1);
218     TextureVertex::set(vertex++, x2, y1, u2, v1);
219     TextureVertex::set(vertex++, x1, y2, u1, v2);
220     TextureVertex::set(vertex++, x2, y2, u2, v2);
221 
222     verticesCount += 4;
223     indexCount += 6;
224 
225 #if DEBUG_PATCHES_VERTICES
226     PATCH_LOGD("    quad %d", oldQuadCount);
227     PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.8f, %.8f", x1, y1, u1, v1);
228     PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.8f, %.8f", x2, y2, u2, v2);
229 #endif
230 }
231 
232 }; // namespace uirenderer
233 }; // namespace android
234