Patch.cpp revision 70561df470c31513056df181571632851fd0d081 
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 "Patch.h"
24#include "Caches.h"
25#include "Properties.h"
26
27namespace android {
28namespace uirenderer {
29
30///////////////////////////////////////////////////////////////////////////////
31// Constructors/destructor
32///////////////////////////////////////////////////////////////////////////////
33
34Patch::Patch(const uint32_t xCount, const uint32_t yCount, const int8_t emptyQuads):
35        mXCount(xCount), mYCount(yCount), mEmptyQuads(emptyQuads) {
36    // Initialized with the maximum number of vertices we will need
37    // 2 triangles per patch, 3 vertices per triangle
38    uint32_t maxVertices = ((xCount + 1) * (yCount + 1) - emptyQuads) * 2 * 3;
39    mVertices = new TextureVertex[maxVertices];
40    mUploaded = false;
41
42    verticesCount = 0;
43    hasEmptyQuads = emptyQuads > 0;
44
45    mColorKey = 0;
46    mXDivs = new int32_t[mXCount];
47    mYDivs = new int32_t[mYCount];
48
49    PATCH_LOGD("    patch: xCount = %d, yCount = %d, emptyQuads = %d, max vertices = %d",
50            xCount, yCount, emptyQuads, maxVertices);
51
52    glGenBuffers(1, &meshBuffer);
53}
54
55Patch::~Patch() {
56    delete[] mVertices;
57    delete[] mXDivs;
58    delete[] mYDivs;
59    glDeleteBuffers(1, &meshBuffer);
60}
61
62///////////////////////////////////////////////////////////////////////////////
63// Patch management
64///////////////////////////////////////////////////////////////////////////////
65
66void Patch::copy(const int32_t* xDivs, const int32_t* yDivs) {
67    memcpy(mXDivs, xDivs, mXCount * sizeof(int32_t));
68    memcpy(mYDivs, yDivs, mYCount * sizeof(int32_t));
69}
70
71void Patch::copy(const int32_t* yDivs) {
72    memcpy(mYDivs, yDivs, mYCount * sizeof(int32_t));
73}
74
75void Patch::updateColorKey(const uint32_t colorKey) {
76    mColorKey = colorKey;
77}
78
79bool Patch::matches(const int32_t* xDivs, const int32_t* yDivs, const uint32_t colorKey) {
80    if (mColorKey != colorKey) {
81        updateColorKey(colorKey);
82        copy(xDivs, yDivs);
83        return false;
84    }
85
86    for (uint32_t i = 0; i < mXCount; i++) {
87        if (mXDivs[i] != xDivs[i]) {
88            // The Y divs may or may not match, copy everything
89            copy(xDivs, yDivs);
90            return false;
91        }
92    }
93
94    for (uint32_t i = 0; i < mYCount; i++) {
95        if (mYDivs[i] != yDivs[i]) {
96            // We know all the X divs match, copy only Y divs
97            copy(yDivs);
98            return false;
99        }
100    }
101
102    return true;
103}
104
105///////////////////////////////////////////////////////////////////////////////
106// Vertices management
107///////////////////////////////////////////////////////////////////////////////
108
109void Patch::updateVertices(const float bitmapWidth, const float bitmapHeight,
110        float left, float top, float right, float bottom) {
111    if (hasEmptyQuads) quads.clear();
112
113    // Reset the vertices count here, we will count exactly how many
114    // vertices we actually need when generating the quads
115    verticesCount = 0;
116
117    const uint32_t xStretchCount = (mXCount + 1) >> 1;
118    const uint32_t yStretchCount = (mYCount + 1) >> 1;
119
120    float stretchX = 0.0f;
121    float stretchY = 0.0;
122
123    const float meshWidth = right - left;
124
125    if (xStretchCount > 0) {
126        uint32_t stretchSize = 0;
127        for (uint32_t i = 1; i < mXCount; i += 2) {
128            stretchSize += mXDivs[i] - mXDivs[i - 1];
129        }
130        const float xStretchTex = stretchSize;
131        const float fixed = bitmapWidth - stretchSize;
132        const float xStretch = right - left - fixed;
133        stretchX = xStretch / xStretchTex;
134    }
135
136    if (yStretchCount > 0) {
137        uint32_t stretchSize = 0;
138        for (uint32_t i = 1; i < mYCount; i += 2) {
139            stretchSize += mYDivs[i] - mYDivs[i - 1];
140        }
141        const float yStretchTex = stretchSize;
142        const float fixed = bitmapHeight - stretchSize;
143        const float yStretch = bottom - top - fixed;
144        stretchY = yStretch / yStretchTex;
145    }
146
147    TextureVertex* vertex = mVertices;
148    uint32_t quadCount = 0;
149
150    float previousStepY = 0.0f;
151
152    float y1 = 0.0f;
153    float y2 = 0.0f;
154    float v1 = 0.0f;
155
156    for (uint32_t i = 0; i < mYCount; i++) {
157        float stepY = mYDivs[i];
158        const float segment = stepY - previousStepY;
159
160        if (i & 1) {
161            y2 = y1 + floorf(segment * stretchY + 0.5f);
162        } else {
163            y2 = y1 + segment;
164        }
165
166        float vOffset = y1 == y2 ? 0.0f : 0.5 - (0.5 * segment / (y2 - y1));
167        float v2 = fmax(0.0f, stepY - vOffset) / bitmapHeight;
168        v1 += vOffset / bitmapHeight;
169
170        if (stepY > 0.0f) {
171#if DEBUG_EXPLODE_PATCHES
172            y1 += i * EXPLODE_GAP;
173            y2 += i * EXPLODE_GAP;
174#endif
175            generateRow(vertex, y1, y2, v1, v2, stretchX, right - left,
176                    bitmapWidth, quadCount);
177#if DEBUG_EXPLODE_PATCHES
178            y2 -= i * EXPLODE_GAP;
179#endif
180        }
181
182        y1 = y2;
183        v1 = stepY / bitmapHeight;
184
185        previousStepY = stepY;
186    }
187
188    if (previousStepY != bitmapHeight) {
189        y2 = bottom - top;
190#if DEBUG_EXPLODE_PATCHES
191        y1 += mYCount * EXPLODE_GAP;
192        y2 += mYCount * EXPLODE_GAP;
193#endif
194        generateRow(vertex, y1, y2, v1, 1.0f, stretchX, right - left, bitmapWidth, quadCount);
195    }
196
197    if (verticesCount > 0) {
198        Caches& caches = Caches::getInstance();
199        caches.bindMeshBuffer(meshBuffer);
200        if (!mUploaded) {
201            glBufferData(GL_ARRAY_BUFFER, sizeof(TextureVertex) * verticesCount,
202                    mVertices, GL_DYNAMIC_DRAW);
203            mUploaded = true;
204        } else {
205            glBufferSubData(GL_ARRAY_BUFFER, 0,
206                    sizeof(TextureVertex) * verticesCount, mVertices);
207        }
208        caches.resetVertexPointers();
209    }
210
211    PATCH_LOGD("    patch: new vertices count = %d", verticesCount);
212}
213
214void Patch::generateRow(TextureVertex*& vertex, float y1, float y2, float v1, float v2,
215        float stretchX, float width, float bitmapWidth, uint32_t& quadCount) {
216    float previousStepX = 0.0f;
217
218    float x1 = 0.0f;
219    float x2 = 0.0f;
220    float u1 = 0.0f;
221
222    // Generate the row quad by quad
223    for (uint32_t i = 0; i < mXCount; i++) {
224        float stepX = mXDivs[i];
225        const float segment = stepX - previousStepX;
226
227        if (i & 1) {
228            x2 = x1 + floorf(segment * stretchX + 0.5f);
229        } else {
230            x2 = x1 + segment;
231        }
232
233        float uOffset = x1 == x2 ? 0.0f : 0.5 - (0.5 * segment / (x2 - x1));
234        float u2 = fmax(0.0f, stepX - uOffset) / bitmapWidth;
235        u1 += uOffset / bitmapWidth;
236
237        if (stepX > 0.0f) {
238#if DEBUG_EXPLODE_PATCHES
239            x1 += i * EXPLODE_GAP;
240            x2 += i * EXPLODE_GAP;
241#endif
242            generateQuad(vertex, x1, y1, x2, y2, u1, v1, u2, v2, quadCount);
243#if DEBUG_EXPLODE_PATCHES
244            x2 -= i * EXPLODE_GAP;
245#endif
246        }
247
248        x1 = x2;
249        u1 = stepX / bitmapWidth;
250
251        previousStepX = stepX;
252    }
253
254    if (previousStepX != bitmapWidth) {
255        x2 = width;
256#if DEBUG_EXPLODE_PATCHES
257        x1 += mXCount * EXPLODE_GAP;
258        x2 += mXCount * EXPLODE_GAP;
259#endif
260        generateQuad(vertex, x1, y1, x2, y2, u1, v1, 1.0f, v2, quadCount);
261    }
262}
263
264void Patch::generateQuad(TextureVertex*& vertex, float x1, float y1, float x2, float y2,
265            float u1, float v1, float u2, float v2, uint32_t& quadCount) {
266    const uint32_t oldQuadCount = quadCount;
267    quadCount++;
268
269    if (x1 < 0.0f) x1 = 0.0f;
270    if (x2 < 0.0f) x2 = 0.0f;
271    if (y1 < 0.0f) y1 = 0.0f;
272    if (y2 < 0.0f) y2 = 0.0f;
273
274    // Skip degenerate and transparent (empty) quads
275    if ((mColorKey >> oldQuadCount) & 0x1) {
276#if DEBUG_PATCHES_EMPTY_VERTICES
277        PATCH_LOGD("    quad %d (empty)", oldQuadCount);
278        PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.4f, %.4f", x1, y1, u1, v1);
279        PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.4f, %.4f", x2, y2, u2, v2);
280#endif
281        return;
282    }
283
284    // Record all non empty quads
285    if (hasEmptyQuads) {
286        Rect bounds(x1, y1, x2, y2);
287        quads.add(bounds);
288    }
289
290    // Left triangle
291    TextureVertex::set(vertex++, x1, y1, u1, v1);
292    TextureVertex::set(vertex++, x2, y1, u2, v1);
293    TextureVertex::set(vertex++, x1, y2, u1, v2);
294
295    // Right triangle
296    TextureVertex::set(vertex++, x1, y2, u1, v2);
297    TextureVertex::set(vertex++, x2, y1, u2, v1);
298    TextureVertex::set(vertex++, x2, y2, u2, v2);
299
300    // A quad is made of 2 triangles, 6 vertices
301    verticesCount += 6;
302
303#if DEBUG_PATCHES_VERTICES
304    PATCH_LOGD("    quad %d", oldQuadCount);
305    PATCH_LOGD("        left,  top    = %.2f, %.2f\t\tu1, v1 = %.4f, %.4f", x1, y1, u1, v1);
306    PATCH_LOGD("        right, bottom = %.2f, %.2f\t\tu2, v2 = %.4f, %.4f", x2, y2, u2, v2);
307#endif
308}
309
310}; // namespace uirenderer
311}; // namespace android
312