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1
11 package org.eclipse.swt.internal.image;
12
13 import java.io.ByteArrayOutputStream  ;
14 import java.io.IOException ;
15 import org.eclipse.swt.SWT;
16 import org.eclipse.swt.graphics.ImageData;
17 import org.eclipse.swt.graphics.ImageLoader;
18 import org.eclipse.swt.graphics.RGB;
19
20 final class PngEncoder extends Object {
21
22 static final byte SIGNATURE[] = {(byte) '\211', (byte) 'P', (byte) 'N', (byte) 'G', (byte) '\r', (byte) '\n', (byte) '\032', (byte) '\n'};
23 static final byte TAG_IHDR[] = {(byte) 'I', (byte) 'H', (byte) 'D', (byte) 'R'};
24 static final byte TAG_PLTE[] = {(byte) 'P', (byte) 'L', (byte) 'T', (byte) 'E'};
25 static final byte TAG_TRNS[] = {(byte) 't', (byte) 'R', (byte) 'N', (byte) 'S'};
26 static final byte TAG_IDAT[] = {(byte) 'I', (byte) 'D', (byte) 'A', (byte) 'T'};
27 static final byte TAG_IEND[] = {(byte) 'I', (byte) 'E', (byte) 'N', (byte) 'D'};
28
29 ByteArrayOutputStream bytes = new ByteArrayOutputStream (1024);
30 PngChunk chunk;
31
32 ImageLoader loader;
33 ImageData data;
34 int transparencyType;
35
36 int width, height, bitDepth, colorType;
37
38 int compressionMethod = 0;
39 int filterMethod = 0;
40 int interlaceMethod = 0;
41
42 public PngEncoder(ImageLoader loader) {
43
44 this.loader = loader;
45 this.data = loader.data[0];
46 this.transparencyType = data.getTransparencyType();
47
48 this.width = data.width;
49 this.height = data.height;
50
51 this.bitDepth = 8;
52
53 this.colorType = 2;
54
55 if (data.palette.isDirect) {
56 if (transparencyType == SWT.TRANSPARENCY_ALPHA) {
57 this.colorType = 6;
58 }
59 }
60 else {
61 this.colorType = 3;
62 }
63
64 if (!(colorType == 2 || colorType == 3 || colorType == 6)) SWT.error(SWT.ERROR_INVALID_IMAGE);
65
66 }
67
68 void writeShort(ByteArrayOutputStream baos, int theShort) {
69
70 byte byte1 = (byte) ((theShort >> 8) & 0xff);
71 byte byte2 = (byte) (theShort & 0xff);
72 byte[] temp = {byte1, byte2};
73 baos.write(temp, 0, 2);
74
75 }
76
77 void writeInt(ByteArrayOutputStream baos, int theInt) {
78
79 byte byte1 = (byte) ((theInt >> 24) & 0xff);
80 byte byte2 = (byte) ((theInt >> 16) & 0xff);
81 byte byte3 = (byte) ((theInt >> 8) & 0xff);
82 byte byte4 = (byte) (theInt & 0xff);
83 byte[] temp = {byte1, byte2, byte3, byte4};
84 baos.write(temp, 0, 4);
85
86 }
87
88 void writeChunk(byte[] tag, byte[] buffer) {
89
90 int bufferLength = (buffer != null) ? buffer.length : 0;
91
92 chunk = new PngChunk(bufferLength);
93
94 writeInt(bytes, bufferLength);
95 bytes.write(tag, 0, 4);
96 chunk.setType(tag);
97 if (bufferLength != 0) {
98 bytes.write(buffer, 0, bufferLength);
99 chunk.setData(buffer);
100 }
101 else {
102 chunk.setCRC(chunk.computeCRC());
103 }
104 writeInt(bytes, chunk.getCRC());
105
106 }
107
108 void writeSignature() {
109
110 bytes.write(SIGNATURE, 0, 8);
111
112 }
113
114 void writeHeader() {
115
116 ByteArrayOutputStream baos = new ByteArrayOutputStream (13);
117
118 writeInt(baos, width);
119 writeInt(baos, height);
120 baos.write(bitDepth);
121 baos.write(colorType);
122 baos.write(compressionMethod);
123 baos.write(filterMethod);
124 baos.write(interlaceMethod);
125
126 writeChunk(TAG_IHDR, baos.toByteArray());
127
128 }
129
130 void writePalette() {
131
132 RGB[] RGBs = data.palette.getRGBs();
133
134 if (RGBs.length > 256) SWT.error(SWT.ERROR_INVALID_IMAGE);
135
136 ByteArrayOutputStream baos = new ByteArrayOutputStream (RGBs.length);
137
138 for (int i = 0; i < RGBs.length; i++) {
139
140 baos.write((byte) RGBs[i].red);
141 baos.write((byte) RGBs[i].green);
142 baos.write((byte) RGBs[i].blue);
143
144 }
145
146 writeChunk(TAG_PLTE, baos.toByteArray());
147
148 }
149
150 void writeTransparency() {
151
152 ByteArrayOutputStream baos = new ByteArrayOutputStream ();
153
154 switch (transparencyType) {
155
156 case SWT.TRANSPARENCY_ALPHA:
157
158 int pixelValue, alphaValue;
159
160 byte[] alphas = new byte[data.palette.getRGBs().length];
161
162 for (int y = 0; y < height; y++) {
163
164 for (int x = 0; x < width; x++) {
165
166 pixelValue = data.getPixel(x, y);
167 alphaValue = data.getAlpha(x, y);
168
169 alphas[pixelValue] = (byte) alphaValue;
170
171 }
172
173 }
174
175 baos.write(alphas, 0, alphas.length);
176
177 break;
178
179 case SWT.TRANSPARENCY_PIXEL:
180
181 int pixel = data.transparentPixel;
182
183 if (colorType == 2) {
184
185 int redMask = data.palette.redMask;
186 int redShift = data.palette.redShift;
187 int greenMask = data.palette.greenMask;
188 int greenShift = data.palette.greenShift;
189 int blueShift = data.palette.blueShift;
190 int blueMask = data.palette.blueMask;
191
192 int r = pixel & redMask;
193 r = (redShift < 0) ? r >>> -redShift : r << redShift;
194 int g = pixel & greenMask;
195 g = (greenShift < 0) ? g >>> -greenShift : g << greenShift;
196 int b = pixel & blueMask;
197 b = (blueShift < 0) ? b >>> -blueShift : b << blueShift;
198
199 writeShort(baos, r);
200 writeShort(baos, g);
201 writeShort(baos, b);
202
203 }
204
205 if (colorType == 3) {
206
207 byte[] padding = new byte[pixel + 1];
208
209 for (int i = 0; i < pixel; i++) {
210
211 padding[i] = (byte) 255;
212
213 }
214
215 padding[pixel] = (byte) 0;
216
217 baos.write(padding, 0, padding.length);
218
219 }
220
221 break;
222
223 }
224
225 writeChunk(TAG_TRNS, baos.toByteArray());
226
227 }
228
229 void writeImageData() {
230
231 ByteArrayOutputStream baos = new ByteArrayOutputStream (1024);
232
233 if (colorType == 3) {
234
235 int[] lineData = new int[width];
236
237 for (int y = 0; y < height; y++) {
238
239 byte filter[] = {0};
240 baos.write(filter, 0, 1);
241
242 data.getPixels(0, y, width, lineData, 0);
243
244 for (int x = 0; x < lineData.length; x++) {
245
246 baos.write((byte) lineData[x]);
247
248 }
249
250 }
251
252 }
253
254 else {
255
256 int[] lineData = new int[width];
257 byte[] alphaData = new byte[width];
258
259 int redMask = data.palette.redMask;
260 int redShift = data.palette.redShift;
261 int greenMask = data.palette.greenMask;
262 int greenShift = data.palette.greenShift;
263 int blueShift = data.palette.blueShift;
264 int blueMask = data.palette.blueMask;
265
266 for (int y = 0; y < height; y++) {
267
268 byte filter[] = {0};
269 baos.write(filter, 0, 1);
270
271 data.getPixels(0, y, width, lineData, 0);
272
273 if (colorType == 6) {
274 data.getAlphas(0, y, width, alphaData, 0);
275 }
276
277 for (int x = 0; x < lineData.length; x++) {
278
279 int pixel = lineData[x];
280
281 int r = pixel & redMask;
282 r = (redShift < 0) ? r >>> -redShift : r << redShift;
283 int g = pixel & greenMask;
284 g = (greenShift < 0) ? g >>> -greenShift : g << greenShift;
285 int b = pixel & blueMask;
286 b = (blueShift < 0) ? b >>> -blueShift : b << blueShift;
287
288 byte pixels[] = {(byte) r, (byte) g, (byte) b};
289 baos.write(pixels, 0, 3);
290
291 if (colorType == 6) {
292
293 byte alpha[] = {alphaData[x]};
294 baos.write(alpha, 0, 1);
295
296 }
297
298 }
299
300 }
301
302 }
303
304 PngDeflater deflater = new PngDeflater();
305 byte[] compressed = deflater.deflate(baos.toByteArray());
306
307 writeChunk(TAG_IDAT, compressed);
308
309 }
310
311 void writeEnd() {
312
313 writeChunk(TAG_IEND, null);
314
315 }
316
317 public void encode(LEDataOutputStream outputStream) {
318
319 try {
320
321 writeSignature();
322 writeHeader();
323
324 if (colorType == 3) {
325 writePalette();
326 }
327
328 boolean transparencyAlpha = (transparencyType == SWT.TRANSPARENCY_ALPHA);
329 boolean transparencyPixel = (transparencyType == SWT.TRANSPARENCY_PIXEL);
330 boolean type2Transparency = (colorType == 2 && transparencyPixel);
331 boolean type3Transparency = (colorType == 3 && (transparencyAlpha || transparencyPixel));
332
333 if (type2Transparency || type3Transparency) {
334 writeTransparency();
335 }
336
337 writeImageData();
338 writeEnd();
339
340 outputStream.write(bytes.toByteArray());
341
342 }
343
344 catch (IOException e) {
345
346 SWT.error(SWT.ERROR_IO, e);
347
348 }
349
350 }
351
352 }
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