1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "ui/gfx/skbitmap_operations.h" 6 7 #include <algorithm> 8 #include <string.h> 9 10 #include "base/logging.h" 11 #include "skia/ext/refptr.h" 12 #include "third_party/skia/include/core/SkBitmap.h" 13 #include "third_party/skia/include/core/SkCanvas.h" 14 #include "third_party/skia/include/core/SkColorFilter.h" 15 #include "third_party/skia/include/core/SkColorPriv.h" 16 #include "third_party/skia/include/core/SkUnPreMultiply.h" 17 #include "third_party/skia/include/effects/SkBlurImageFilter.h" 18 #include "ui/gfx/insets.h" 19 #include "ui/gfx/point.h" 20 #include "ui/gfx/size.h" 21 22 // static 23 SkBitmap SkBitmapOperations::CreateInvertedBitmap(const SkBitmap& image) { 24 DCHECK(image.config() == SkBitmap::kARGB_8888_Config); 25 26 SkAutoLockPixels lock_image(image); 27 28 SkBitmap inverted; 29 inverted.setConfig(SkBitmap::kARGB_8888_Config, image.width(), image.height(), 30 0); 31 inverted.allocPixels(); 32 inverted.eraseARGB(0, 0, 0, 0); 33 34 for (int y = 0; y < image.height(); ++y) { 35 uint32* image_row = image.getAddr32(0, y); 36 uint32* dst_row = inverted.getAddr32(0, y); 37 38 for (int x = 0; x < image.width(); ++x) { 39 uint32 image_pixel = image_row[x]; 40 dst_row[x] = (image_pixel & 0xFF000000) | 41 (0x00FFFFFF - (image_pixel & 0x00FFFFFF)); 42 } 43 } 44 45 return inverted; 46 } 47 48 // static 49 SkBitmap SkBitmapOperations::CreateSuperimposedBitmap(const SkBitmap& first, 50 const SkBitmap& second) { 51 DCHECK(first.width() == second.width()); 52 DCHECK(first.height() == second.height()); 53 DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); 54 DCHECK(first.config() == SkBitmap::kARGB_8888_Config); 55 56 SkAutoLockPixels lock_first(first); 57 SkAutoLockPixels lock_second(second); 58 59 SkBitmap superimposed; 60 superimposed.setConfig(SkBitmap::kARGB_8888_Config, 61 first.width(), first.height()); 62 superimposed.allocPixels(); 63 superimposed.eraseARGB(0, 0, 0, 0); 64 65 SkCanvas canvas(superimposed); 66 67 SkRect rect; 68 rect.fLeft = 0; 69 rect.fTop = 0; 70 rect.fRight = SkIntToScalar(first.width()); 71 rect.fBottom = SkIntToScalar(first.height()); 72 73 canvas.drawBitmapRect(first, NULL, rect); 74 canvas.drawBitmapRect(second, NULL, rect); 75 76 return superimposed; 77 } 78 79 // static 80 SkBitmap SkBitmapOperations::CreateBlendedBitmap(const SkBitmap& first, 81 const SkBitmap& second, 82 double alpha) { 83 DCHECK((alpha >= 0) && (alpha <= 1)); 84 DCHECK(first.width() == second.width()); 85 DCHECK(first.height() == second.height()); 86 DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); 87 DCHECK(first.config() == SkBitmap::kARGB_8888_Config); 88 89 // Optimize for case where we won't need to blend anything. 90 static const double alpha_min = 1.0 / 255; 91 static const double alpha_max = 254.0 / 255; 92 if (alpha < alpha_min) 93 return first; 94 else if (alpha > alpha_max) 95 return second; 96 97 SkAutoLockPixels lock_first(first); 98 SkAutoLockPixels lock_second(second); 99 100 SkBitmap blended; 101 blended.setConfig(SkBitmap::kARGB_8888_Config, first.width(), first.height(), 102 0); 103 blended.allocPixels(); 104 blended.eraseARGB(0, 0, 0, 0); 105 106 double first_alpha = 1 - alpha; 107 108 for (int y = 0; y < first.height(); ++y) { 109 uint32* first_row = first.getAddr32(0, y); 110 uint32* second_row = second.getAddr32(0, y); 111 uint32* dst_row = blended.getAddr32(0, y); 112 113 for (int x = 0; x < first.width(); ++x) { 114 uint32 first_pixel = first_row[x]; 115 uint32 second_pixel = second_row[x]; 116 117 int a = static_cast<int>((SkColorGetA(first_pixel) * first_alpha) + 118 (SkColorGetA(second_pixel) * alpha)); 119 int r = static_cast<int>((SkColorGetR(first_pixel) * first_alpha) + 120 (SkColorGetR(second_pixel) * alpha)); 121 int g = static_cast<int>((SkColorGetG(first_pixel) * first_alpha) + 122 (SkColorGetG(second_pixel) * alpha)); 123 int b = static_cast<int>((SkColorGetB(first_pixel) * first_alpha) + 124 (SkColorGetB(second_pixel) * alpha)); 125 126 dst_row[x] = SkColorSetARGB(a, r, g, b); 127 } 128 } 129 130 return blended; 131 } 132 133 // static 134 SkBitmap SkBitmapOperations::CreateMaskedBitmap(const SkBitmap& rgb, 135 const SkBitmap& alpha) { 136 DCHECK(rgb.width() == alpha.width()); 137 DCHECK(rgb.height() == alpha.height()); 138 DCHECK(rgb.bytesPerPixel() == alpha.bytesPerPixel()); 139 DCHECK(rgb.config() == SkBitmap::kARGB_8888_Config); 140 DCHECK(alpha.config() == SkBitmap::kARGB_8888_Config); 141 142 SkBitmap masked; 143 masked.setConfig(SkBitmap::kARGB_8888_Config, rgb.width(), rgb.height(), 0); 144 masked.allocPixels(); 145 masked.eraseARGB(0, 0, 0, 0); 146 147 SkAutoLockPixels lock_rgb(rgb); 148 SkAutoLockPixels lock_alpha(alpha); 149 SkAutoLockPixels lock_masked(masked); 150 151 for (int y = 0; y < masked.height(); ++y) { 152 uint32* rgb_row = rgb.getAddr32(0, y); 153 uint32* alpha_row = alpha.getAddr32(0, y); 154 uint32* dst_row = masked.getAddr32(0, y); 155 156 for (int x = 0; x < masked.width(); ++x) { 157 SkColor rgb_pixel = SkUnPreMultiply::PMColorToColor(rgb_row[x]); 158 SkColor alpha_pixel = SkUnPreMultiply::PMColorToColor(alpha_row[x]); 159 int alpha = SkAlphaMul(SkColorGetA(rgb_pixel), 160 SkAlpha255To256(SkColorGetA(alpha_pixel))); 161 int alpha_256 = SkAlpha255To256(alpha); 162 dst_row[x] = SkColorSetARGB(alpha, 163 SkAlphaMul(SkColorGetR(rgb_pixel), alpha_256), 164 SkAlphaMul(SkColorGetG(rgb_pixel), alpha_256), 165 SkAlphaMul(SkColorGetB(rgb_pixel), 166 alpha_256)); 167 } 168 } 169 170 return masked; 171 } 172 173 // static 174 SkBitmap SkBitmapOperations::CreateButtonBackground(SkColor color, 175 const SkBitmap& image, 176 const SkBitmap& mask) { 177 DCHECK(image.config() == SkBitmap::kARGB_8888_Config); 178 DCHECK(mask.config() == SkBitmap::kARGB_8888_Config); 179 180 SkBitmap background; 181 background.setConfig( 182 SkBitmap::kARGB_8888_Config, mask.width(), mask.height(), 0); 183 background.allocPixels(); 184 185 double bg_a = SkColorGetA(color); 186 double bg_r = SkColorGetR(color); 187 double bg_g = SkColorGetG(color); 188 double bg_b = SkColorGetB(color); 189 190 SkAutoLockPixels lock_mask(mask); 191 SkAutoLockPixels lock_image(image); 192 SkAutoLockPixels lock_background(background); 193 194 for (int y = 0; y < mask.height(); ++y) { 195 uint32* dst_row = background.getAddr32(0, y); 196 uint32* image_row = image.getAddr32(0, y % image.height()); 197 uint32* mask_row = mask.getAddr32(0, y); 198 199 for (int x = 0; x < mask.width(); ++x) { 200 uint32 image_pixel = image_row[x % image.width()]; 201 202 double img_a = SkColorGetA(image_pixel); 203 double img_r = SkColorGetR(image_pixel); 204 double img_g = SkColorGetG(image_pixel); 205 double img_b = SkColorGetB(image_pixel); 206 207 double img_alpha = static_cast<double>(img_a) / 255.0; 208 double img_inv = 1 - img_alpha; 209 210 double mask_a = static_cast<double>(SkColorGetA(mask_row[x])) / 255.0; 211 212 dst_row[x] = SkColorSetARGB( 213 static_cast<int>(std::min(255.0, bg_a + img_a) * mask_a), 214 static_cast<int>(((bg_r * img_inv) + (img_r * img_alpha)) * mask_a), 215 static_cast<int>(((bg_g * img_inv) + (img_g * img_alpha)) * mask_a), 216 static_cast<int>(((bg_b * img_inv) + (img_b * img_alpha)) * mask_a)); 217 } 218 } 219 220 return background; 221 } 222 223 namespace { 224 namespace HSLShift { 225 226 // TODO(viettrungluu): Some things have yet to be optimized at all. 227 228 // Notes on and conventions used in the following code 229 // 230 // Conventions: 231 // - R, G, B, A = obvious; as variables: |r|, |g|, |b|, |a| (see also below) 232 // - H, S, L = obvious; as variables: |h|, |s|, |l| (see also below) 233 // - variables derived from S, L shift parameters: |sdec| and |sinc| for S 234 // increase and decrease factors, |ldec| and |linc| for L (see also below) 235 // 236 // To try to optimize HSL shifts, we do several things: 237 // - Avoid unpremultiplying (then processing) then premultiplying. This means 238 // that R, G, B values (and also L, but not H and S) should be treated as 239 // having a range of 0..A (where A is alpha). 240 // - Do things in integer/fixed-point. This avoids costly conversions between 241 // floating-point and integer, though I should study the tradeoff more 242 // carefully (presumably, at some point of processing complexity, converting 243 // and processing using simpler floating-point code will begin to win in 244 // performance). Also to be studied is the speed/type of floating point 245 // conversions; see, e.g., <http://www.stereopsis.com/sree/fpu2006.html>. 246 // 247 // Conventions for fixed-point arithmetic 248 // - Each function has a constant denominator (called |den|, which should be a 249 // power of 2), appropriate for the computations done in that function. 250 // - A value |x| is then typically represented by a numerator, named |x_num|, 251 // so that its actual value is |x_num / den| (casting to floating-point 252 // before division). 253 // - To obtain |x_num| from |x|, simply multiply by |den|, i.e., |x_num = x * 254 // den| (casting appropriately). 255 // - When necessary, a value |x| may also be represented as a numerator over 256 // the denominator squared (set |den2 = den * den|). In such a case, the 257 // corresponding variable is called |x_num2| (so that its actual value is 258 // |x_num^2 / den2|. 259 // - The representation of the product of |x| and |y| is be called |x_y_num| if 260 // |x * y == x_y_num / den|, and |xy_num2| if |x * y == x_y_num2 / den2|. In 261 // the latter case, notice that one can calculate |x_y_num2 = x_num * y_num|. 262 263 // Routine used to process a line; typically specialized for specific kinds of 264 // HSL shifts (to optimize). 265 typedef void (*LineProcessor)(const color_utils::HSL&, 266 const SkPMColor*, 267 SkPMColor*, 268 int width); 269 270 enum OperationOnH { kOpHNone = 0, kOpHShift, kNumHOps }; 271 enum OperationOnS { kOpSNone = 0, kOpSDec, kOpSInc, kNumSOps }; 272 enum OperationOnL { kOpLNone = 0, kOpLDec, kOpLInc, kNumLOps }; 273 274 // Epsilon used to judge when shift values are close enough to various critical 275 // values (typically 0.5, which yields a no-op for S and L shifts. 1/256 should 276 // be small enough, but let's play it safe> 277 const double epsilon = 0.0005; 278 279 // Line processor: default/universal (i.e., old-school). 280 void LineProcDefault(const color_utils::HSL& hsl_shift, 281 const SkPMColor* in, 282 SkPMColor* out, 283 int width) { 284 for (int x = 0; x < width; x++) { 285 out[x] = SkPreMultiplyColor(color_utils::HSLShift( 286 SkUnPreMultiply::PMColorToColor(in[x]), hsl_shift)); 287 } 288 } 289 290 // Line processor: no-op (i.e., copy). 291 void LineProcCopy(const color_utils::HSL& hsl_shift, 292 const SkPMColor* in, 293 SkPMColor* out, 294 int width) { 295 DCHECK(hsl_shift.h < 0); 296 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 297 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 298 memcpy(out, in, static_cast<size_t>(width) * sizeof(out[0])); 299 } 300 301 // Line processor: H no-op, S no-op, L decrease. 302 void LineProcHnopSnopLdec(const color_utils::HSL& hsl_shift, 303 const SkPMColor* in, 304 SkPMColor* out, 305 int width) { 306 const uint32_t den = 65536; 307 308 DCHECK(hsl_shift.h < 0); 309 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 310 DCHECK(hsl_shift.l <= 0.5 - HSLShift::epsilon && hsl_shift.l >= 0); 311 312 uint32_t ldec_num = static_cast<uint32_t>(hsl_shift.l * 2 * den); 313 for (int x = 0; x < width; x++) { 314 uint32_t a = SkGetPackedA32(in[x]); 315 uint32_t r = SkGetPackedR32(in[x]); 316 uint32_t g = SkGetPackedG32(in[x]); 317 uint32_t b = SkGetPackedB32(in[x]); 318 r = r * ldec_num / den; 319 g = g * ldec_num / den; 320 b = b * ldec_num / den; 321 out[x] = SkPackARGB32(a, r, g, b); 322 } 323 } 324 325 // Line processor: H no-op, S no-op, L increase. 326 void LineProcHnopSnopLinc(const color_utils::HSL& hsl_shift, 327 const SkPMColor* in, 328 SkPMColor* out, 329 int width) { 330 const uint32_t den = 65536; 331 332 DCHECK(hsl_shift.h < 0); 333 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 334 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 335 336 uint32_t linc_num = static_cast<uint32_t>((hsl_shift.l - 0.5) * 2 * den); 337 for (int x = 0; x < width; x++) { 338 uint32_t a = SkGetPackedA32(in[x]); 339 uint32_t r = SkGetPackedR32(in[x]); 340 uint32_t g = SkGetPackedG32(in[x]); 341 uint32_t b = SkGetPackedB32(in[x]); 342 r += (a - r) * linc_num / den; 343 g += (a - g) * linc_num / den; 344 b += (a - b) * linc_num / den; 345 out[x] = SkPackARGB32(a, r, g, b); 346 } 347 } 348 349 // Saturation changes modifications in RGB 350 // 351 // (Note that as a further complication, the values we deal in are 352 // premultiplied, so R/G/B values must be in the range 0..A. For mathematical 353 // purposes, one may as well use r=R/A, g=G/A, b=B/A. Without loss of 354 // generality, assume that R/G/B values are in the range 0..1.) 355 // 356 // Let Max = max(R,G,B), Min = min(R,G,B), and Med be the median value. Then L = 357 // (Max+Min)/2. If L is to remain constant, Max+Min must also remain constant. 358 // 359 // For H to remain constant, first, the (numerical) order of R/G/B (from 360 // smallest to largest) must remain the same. Second, all the ratios 361 // (R-G)/(Max-Min), (R-B)/(Max-Min), (G-B)/(Max-Min) must remain constant (of 362 // course, if Max = Min, then S = 0 and no saturation change is well-defined, 363 // since H is not well-defined). 364 // 365 // Let C_max be a colour with value Max, C_min be one with value Min, and C_med 366 // the remaining colour. Increasing saturation (to the maximum) is accomplished 367 // by increasing the value of C_max while simultaneously decreasing C_min and 368 // changing C_med so that the ratios are maintained; for the latter, it suffices 369 // to keep (C_med-C_min)/(C_max-C_min) constant (and equal to 370 // (Med-Min)/(Max-Min)). 371 372 // Line processor: H no-op, S decrease, L no-op. 373 void LineProcHnopSdecLnop(const color_utils::HSL& hsl_shift, 374 const SkPMColor* in, 375 SkPMColor* out, 376 int width) { 377 DCHECK(hsl_shift.h < 0); 378 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 379 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 380 381 const int32_t denom = 65536; 382 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 383 for (int x = 0; x < width; x++) { 384 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 385 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 386 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 387 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 388 389 int32_t vmax, vmin; 390 if (r > g) { // This uses 3 compares rather than 4. 391 vmax = std::max(r, b); 392 vmin = std::min(g, b); 393 } else { 394 vmax = std::max(g, b); 395 vmin = std::min(r, b); 396 } 397 398 // Use denom * L to avoid rounding. 399 int32_t denom_l = (vmax + vmin) * (denom / 2); 400 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 401 402 r = (denom_l + r * s_numer - s_numer_l) / denom; 403 g = (denom_l + g * s_numer - s_numer_l) / denom; 404 b = (denom_l + b * s_numer - s_numer_l) / denom; 405 out[x] = SkPackARGB32(a, r, g, b); 406 } 407 } 408 409 // Line processor: H no-op, S decrease, L decrease. 410 void LineProcHnopSdecLdec(const color_utils::HSL& hsl_shift, 411 const SkPMColor* in, 412 SkPMColor* out, 413 int width) { 414 DCHECK(hsl_shift.h < 0); 415 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 416 DCHECK(hsl_shift.l >= 0 && hsl_shift.l <= 0.5 - HSLShift::epsilon); 417 418 // Can't be too big since we need room for denom*denom and a bit for sign. 419 const int32_t denom = 1024; 420 int32_t l_numer = static_cast<int32_t>(hsl_shift.l * 2 * denom); 421 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 422 for (int x = 0; x < width; x++) { 423 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 424 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 425 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 426 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 427 428 int32_t vmax, vmin; 429 if (r > g) { // This uses 3 compares rather than 4. 430 vmax = std::max(r, b); 431 vmin = std::min(g, b); 432 } else { 433 vmax = std::max(g, b); 434 vmin = std::min(r, b); 435 } 436 437 // Use denom * L to avoid rounding. 438 int32_t denom_l = (vmax + vmin) * (denom / 2); 439 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 440 441 r = (denom_l + r * s_numer - s_numer_l) * l_numer / (denom * denom); 442 g = (denom_l + g * s_numer - s_numer_l) * l_numer / (denom * denom); 443 b = (denom_l + b * s_numer - s_numer_l) * l_numer / (denom * denom); 444 out[x] = SkPackARGB32(a, r, g, b); 445 } 446 } 447 448 // Line processor: H no-op, S decrease, L increase. 449 void LineProcHnopSdecLinc(const color_utils::HSL& hsl_shift, 450 const SkPMColor* in, 451 SkPMColor* out, 452 int width) { 453 DCHECK(hsl_shift.h < 0); 454 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 455 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 456 457 // Can't be too big since we need room for denom*denom and a bit for sign. 458 const int32_t denom = 1024; 459 int32_t l_numer = static_cast<int32_t>((hsl_shift.l - 0.5) * 2 * denom); 460 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 461 for (int x = 0; x < width; x++) { 462 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 463 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 464 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 465 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 466 467 int32_t vmax, vmin; 468 if (r > g) { // This uses 3 compares rather than 4. 469 vmax = std::max(r, b); 470 vmin = std::min(g, b); 471 } else { 472 vmax = std::max(g, b); 473 vmin = std::min(r, b); 474 } 475 476 // Use denom * L to avoid rounding. 477 int32_t denom_l = (vmax + vmin) * (denom / 2); 478 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 479 480 r = denom_l + r * s_numer - s_numer_l; 481 g = denom_l + g * s_numer - s_numer_l; 482 b = denom_l + b * s_numer - s_numer_l; 483 484 r = (r * denom + (a * denom - r) * l_numer) / (denom * denom); 485 g = (g * denom + (a * denom - g) * l_numer) / (denom * denom); 486 b = (b * denom + (a * denom - b) * l_numer) / (denom * denom); 487 out[x] = SkPackARGB32(a, r, g, b); 488 } 489 } 490 491 const LineProcessor kLineProcessors[kNumHOps][kNumSOps][kNumLOps] = { 492 { // H: kOpHNone 493 { // S: kOpSNone 494 LineProcCopy, // L: kOpLNone 495 LineProcHnopSnopLdec, // L: kOpLDec 496 LineProcHnopSnopLinc // L: kOpLInc 497 }, 498 { // S: kOpSDec 499 LineProcHnopSdecLnop, // L: kOpLNone 500 LineProcHnopSdecLdec, // L: kOpLDec 501 LineProcHnopSdecLinc // L: kOpLInc 502 }, 503 { // S: kOpSInc 504 LineProcDefault, // L: kOpLNone 505 LineProcDefault, // L: kOpLDec 506 LineProcDefault // L: kOpLInc 507 } 508 }, 509 { // H: kOpHShift 510 { // S: kOpSNone 511 LineProcDefault, // L: kOpLNone 512 LineProcDefault, // L: kOpLDec 513 LineProcDefault // L: kOpLInc 514 }, 515 { // S: kOpSDec 516 LineProcDefault, // L: kOpLNone 517 LineProcDefault, // L: kOpLDec 518 LineProcDefault // L: kOpLInc 519 }, 520 { // S: kOpSInc 521 LineProcDefault, // L: kOpLNone 522 LineProcDefault, // L: kOpLDec 523 LineProcDefault // L: kOpLInc 524 } 525 } 526 }; 527 528 } // namespace HSLShift 529 } // namespace 530 531 // static 532 SkBitmap SkBitmapOperations::CreateHSLShiftedBitmap( 533 const SkBitmap& bitmap, 534 const color_utils::HSL& hsl_shift) { 535 // Default to NOPs. 536 HSLShift::OperationOnH H_op = HSLShift::kOpHNone; 537 HSLShift::OperationOnS S_op = HSLShift::kOpSNone; 538 HSLShift::OperationOnL L_op = HSLShift::kOpLNone; 539 540 if (hsl_shift.h >= 0 && hsl_shift.h <= 1) 541 H_op = HSLShift::kOpHShift; 542 543 // Saturation shift: 0 -> fully desaturate, 0.5 -> NOP, 1 -> fully saturate. 544 if (hsl_shift.s >= 0 && hsl_shift.s <= (0.5 - HSLShift::epsilon)) 545 S_op = HSLShift::kOpSDec; 546 else if (hsl_shift.s >= (0.5 + HSLShift::epsilon)) 547 S_op = HSLShift::kOpSInc; 548 549 // Lightness shift: 0 -> black, 0.5 -> NOP, 1 -> white. 550 if (hsl_shift.l >= 0 && hsl_shift.l <= (0.5 - HSLShift::epsilon)) 551 L_op = HSLShift::kOpLDec; 552 else if (hsl_shift.l >= (0.5 + HSLShift::epsilon)) 553 L_op = HSLShift::kOpLInc; 554 555 HSLShift::LineProcessor line_proc = 556 HSLShift::kLineProcessors[H_op][S_op][L_op]; 557 558 DCHECK(bitmap.empty() == false); 559 DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config); 560 561 SkBitmap shifted; 562 shifted.setConfig(SkBitmap::kARGB_8888_Config, bitmap.width(), 563 bitmap.height()); 564 shifted.allocPixels(); 565 shifted.eraseARGB(0, 0, 0, 0); 566 567 SkAutoLockPixels lock_bitmap(bitmap); 568 SkAutoLockPixels lock_shifted(shifted); 569 570 // Loop through the pixels of the original bitmap. 571 for (int y = 0; y < bitmap.height(); ++y) { 572 SkPMColor* pixels = bitmap.getAddr32(0, y); 573 SkPMColor* tinted_pixels = shifted.getAddr32(0, y); 574 575 (*line_proc)(hsl_shift, pixels, tinted_pixels, bitmap.width()); 576 } 577 578 return shifted; 579 } 580 581 // static 582 SkBitmap SkBitmapOperations::CreateTiledBitmap(const SkBitmap& source, 583 int src_x, int src_y, 584 int dst_w, int dst_h) { 585 DCHECK(source.config() == SkBitmap::kARGB_8888_Config); 586 587 SkBitmap cropped; 588 cropped.setConfig(SkBitmap::kARGB_8888_Config, dst_w, dst_h, 0); 589 cropped.allocPixels(); 590 cropped.eraseARGB(0, 0, 0, 0); 591 592 SkAutoLockPixels lock_source(source); 593 SkAutoLockPixels lock_cropped(cropped); 594 595 // Loop through the pixels of the original bitmap. 596 for (int y = 0; y < dst_h; ++y) { 597 int y_pix = (src_y + y) % source.height(); 598 while (y_pix < 0) 599 y_pix += source.height(); 600 601 uint32* source_row = source.getAddr32(0, y_pix); 602 uint32* dst_row = cropped.getAddr32(0, y); 603 604 for (int x = 0; x < dst_w; ++x) { 605 int x_pix = (src_x + x) % source.width(); 606 while (x_pix < 0) 607 x_pix += source.width(); 608 609 dst_row[x] = source_row[x_pix]; 610 } 611 } 612 613 return cropped; 614 } 615 616 // static 617 SkBitmap SkBitmapOperations::DownsampleByTwoUntilSize(const SkBitmap& bitmap, 618 int min_w, int min_h) { 619 if ((bitmap.width() <= min_w) || (bitmap.height() <= min_h) || 620 (min_w < 0) || (min_h < 0)) 621 return bitmap; 622 623 // Since bitmaps are refcounted, this copy will be fast. 624 SkBitmap current = bitmap; 625 while ((current.width() >= min_w * 2) && (current.height() >= min_h * 2) && 626 (current.width() > 1) && (current.height() > 1)) 627 current = DownsampleByTwo(current); 628 return current; 629 } 630 631 // static 632 SkBitmap SkBitmapOperations::DownsampleByTwo(const SkBitmap& bitmap) { 633 // Handle the nop case. 634 if ((bitmap.width() <= 1) || (bitmap.height() <= 1)) 635 return bitmap; 636 637 SkBitmap result; 638 result.setConfig(SkBitmap::kARGB_8888_Config, 639 (bitmap.width() + 1) / 2, (bitmap.height() + 1) / 2); 640 result.allocPixels(); 641 642 SkAutoLockPixels lock(bitmap); 643 644 const int resultLastX = result.width() - 1; 645 const int srcLastX = bitmap.width() - 1; 646 647 for (int dest_y = 0; dest_y < result.height(); ++dest_y) { 648 const int src_y = dest_y << 1; 649 const SkPMColor* SK_RESTRICT cur_src0 = bitmap.getAddr32(0, src_y); 650 const SkPMColor* SK_RESTRICT cur_src1 = cur_src0; 651 if (src_y + 1 < bitmap.height()) 652 cur_src1 = bitmap.getAddr32(0, src_y + 1); 653 654 SkPMColor* SK_RESTRICT cur_dst = result.getAddr32(0, dest_y); 655 656 for (int dest_x = 0; dest_x <= resultLastX; ++dest_x) { 657 // This code is based on downsampleby2_proc32 in SkBitmap.cpp. It is very 658 // clever in that it does two channels at once: alpha and green ("ag") 659 // and red and blue ("rb"). Each channel gets averaged across 4 pixels 660 // to get the result. 661 int bump_x = (dest_x << 1) < srcLastX; 662 SkPMColor tmp, ag, rb; 663 664 // Top left pixel of the 2x2 block. 665 tmp = cur_src0[0]; 666 ag = (tmp >> 8) & 0xFF00FF; 667 rb = tmp & 0xFF00FF; 668 669 // Top right pixel of the 2x2 block. 670 tmp = cur_src0[bump_x]; 671 ag += (tmp >> 8) & 0xFF00FF; 672 rb += tmp & 0xFF00FF; 673 674 // Bottom left pixel of the 2x2 block. 675 tmp = cur_src1[0]; 676 ag += (tmp >> 8) & 0xFF00FF; 677 rb += tmp & 0xFF00FF; 678 679 // Bottom right pixel of the 2x2 block. 680 tmp = cur_src1[bump_x]; 681 ag += (tmp >> 8) & 0xFF00FF; 682 rb += tmp & 0xFF00FF; 683 684 // Put the channels back together, dividing each by 4 to get the average. 685 // |ag| has the alpha and green channels shifted right by 8 bits from 686 // there they should end up, so shifting left by 6 gives them in the 687 // correct position divided by 4. 688 *cur_dst++ = ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); 689 690 cur_src0 += 2; 691 cur_src1 += 2; 692 } 693 } 694 695 return result; 696 } 697 698 // static 699 SkBitmap SkBitmapOperations::UnPreMultiply(const SkBitmap& bitmap) { 700 if (bitmap.isNull()) 701 return bitmap; 702 if (bitmap.isOpaque()) 703 return bitmap; 704 705 SkBitmap opaque_bitmap; 706 opaque_bitmap.setConfig(bitmap.config(), bitmap.width(), bitmap.height(), 707 0, kOpaque_SkAlphaType); 708 opaque_bitmap.allocPixels(); 709 710 { 711 SkAutoLockPixels bitmap_lock(bitmap); 712 SkAutoLockPixels opaque_bitmap_lock(opaque_bitmap); 713 for (int y = 0; y < opaque_bitmap.height(); y++) { 714 for (int x = 0; x < opaque_bitmap.width(); x++) { 715 uint32 src_pixel = *bitmap.getAddr32(x, y); 716 uint32* dst_pixel = opaque_bitmap.getAddr32(x, y); 717 SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(src_pixel); 718 *dst_pixel = unmultiplied; 719 } 720 } 721 } 722 723 return opaque_bitmap; 724 } 725 726 // static 727 SkBitmap SkBitmapOperations::CreateTransposedBitmap(const SkBitmap& image) { 728 DCHECK(image.config() == SkBitmap::kARGB_8888_Config); 729 730 SkBitmap transposed; 731 transposed.setConfig( 732 SkBitmap::kARGB_8888_Config, image.height(), image.width(), 0); 733 transposed.allocPixels(); 734 735 SkAutoLockPixels lock_image(image); 736 SkAutoLockPixels lock_transposed(transposed); 737 738 for (int y = 0; y < image.height(); ++y) { 739 uint32* image_row = image.getAddr32(0, y); 740 for (int x = 0; x < image.width(); ++x) { 741 uint32* dst = transposed.getAddr32(y, x); 742 *dst = image_row[x]; 743 } 744 } 745 746 return transposed; 747 } 748 749 // static 750 SkBitmap SkBitmapOperations::CreateColorMask(const SkBitmap& bitmap, 751 SkColor c) { 752 DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config); 753 754 SkBitmap color_mask; 755 color_mask.setConfig(SkBitmap::kARGB_8888_Config, 756 bitmap.width(), bitmap.height()); 757 color_mask.allocPixels(); 758 color_mask.eraseARGB(0, 0, 0, 0); 759 760 SkCanvas canvas(color_mask); 761 762 skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef( 763 SkColorFilter::CreateModeFilter(c, SkXfermode::kSrcIn_Mode)); 764 SkPaint paint; 765 paint.setColorFilter(color_filter.get()); 766 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0), &paint); 767 return color_mask; 768 } 769 770 // static 771 SkBitmap SkBitmapOperations::CreateDropShadow( 772 const SkBitmap& bitmap, 773 const gfx::ShadowValues& shadows) { 774 DCHECK(bitmap.config() == SkBitmap::kARGB_8888_Config); 775 776 // Shadow margin insets are negative values because they grow outside. 777 // Negate them here as grow direction is not important and only pixel value 778 // is of interest here. 779 gfx::Insets shadow_margin = -gfx::ShadowValue::GetMargin(shadows); 780 781 SkBitmap image_with_shadow; 782 image_with_shadow.setConfig(SkBitmap::kARGB_8888_Config, 783 bitmap.width() + shadow_margin.width(), 784 bitmap.height() + shadow_margin.height()); 785 image_with_shadow.allocPixels(); 786 image_with_shadow.eraseARGB(0, 0, 0, 0); 787 788 SkCanvas canvas(image_with_shadow); 789 canvas.translate(SkIntToScalar(shadow_margin.left()), 790 SkIntToScalar(shadow_margin.top())); 791 792 SkPaint paint; 793 for (size_t i = 0; i < shadows.size(); ++i) { 794 const gfx::ShadowValue& shadow = shadows[i]; 795 SkBitmap shadow_image = SkBitmapOperations::CreateColorMask(bitmap, 796 shadow.color()); 797 798 skia::RefPtr<SkBlurImageFilter> filter = 799 skia::AdoptRef(new SkBlurImageFilter(SkDoubleToScalar(shadow.blur()), 800 SkDoubleToScalar(shadow.blur()))); 801 paint.setImageFilter(filter.get()); 802 803 canvas.saveLayer(0, &paint); 804 canvas.drawBitmap(shadow_image, 805 SkIntToScalar(shadow.x()), 806 SkIntToScalar(shadow.y())); 807 canvas.restore(); 808 } 809 810 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0)); 811 return image_with_shadow; 812 } 813 814 // static 815 SkBitmap SkBitmapOperations::Rotate(const SkBitmap& source, 816 RotationAmount rotation) { 817 SkBitmap result; 818 SkScalar angle = SkFloatToScalar(0.0f); 819 820 switch (rotation) { 821 case ROTATION_90_CW: 822 angle = SkFloatToScalar(90.0f); 823 result.setConfig( 824 SkBitmap::kARGB_8888_Config, source.height(), source.width()); 825 break; 826 case ROTATION_180_CW: 827 angle = SkFloatToScalar(180.0f); 828 result.setConfig( 829 SkBitmap::kARGB_8888_Config, source.width(), source.height()); 830 break; 831 case ROTATION_270_CW: 832 angle = SkFloatToScalar(270.0f); 833 result.setConfig( 834 SkBitmap::kARGB_8888_Config, source.height(), source.width()); 835 break; 836 } 837 result.allocPixels(); 838 SkCanvas canvas(result); 839 canvas.clear(SkColorSetARGB(0, 0, 0, 0)); 840 841 canvas.translate(SkFloatToScalar(result.width() * 0.5f), 842 SkFloatToScalar(result.height() * 0.5f)); 843 canvas.rotate(angle); 844 canvas.translate(-SkFloatToScalar(source.width() * 0.5f), 845 -SkFloatToScalar(source.height() * 0.5f)); 846 canvas.drawBitmap(source, 0, 0); 847 canvas.flush(); 848 849 return result; 850 } 851
