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.colorType() == kPMColor_SkColorType); 25 26 SkAutoLockPixels lock_image(image); 27 28 SkBitmap inverted; 29 inverted.allocN32Pixels(image.width(), image.height()); 30 inverted.eraseARGB(0, 0, 0, 0); 31 32 for (int y = 0; y < image.height(); ++y) { 33 uint32* image_row = image.getAddr32(0, y); 34 uint32* dst_row = inverted.getAddr32(0, y); 35 36 for (int x = 0; x < image.width(); ++x) { 37 uint32 image_pixel = image_row[x]; 38 dst_row[x] = (image_pixel & 0xFF000000) | 39 (0x00FFFFFF - (image_pixel & 0x00FFFFFF)); 40 } 41 } 42 43 return inverted; 44 } 45 46 // static 47 SkBitmap SkBitmapOperations::CreateSuperimposedBitmap(const SkBitmap& first, 48 const SkBitmap& second) { 49 DCHECK(first.width() == second.width()); 50 DCHECK(first.height() == second.height()); 51 DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); 52 DCHECK(first.colorType() == kPMColor_SkColorType); 53 54 SkAutoLockPixels lock_first(first); 55 SkAutoLockPixels lock_second(second); 56 57 SkBitmap superimposed; 58 superimposed.allocN32Pixels(first.width(), first.height()); 59 superimposed.eraseARGB(0, 0, 0, 0); 60 61 SkCanvas canvas(superimposed); 62 63 SkRect rect; 64 rect.fLeft = 0; 65 rect.fTop = 0; 66 rect.fRight = SkIntToScalar(first.width()); 67 rect.fBottom = SkIntToScalar(first.height()); 68 69 canvas.drawBitmapRect(first, NULL, rect); 70 canvas.drawBitmapRect(second, NULL, rect); 71 72 return superimposed; 73 } 74 75 // static 76 SkBitmap SkBitmapOperations::CreateBlendedBitmap(const SkBitmap& first, 77 const SkBitmap& second, 78 double alpha) { 79 DCHECK((alpha >= 0) && (alpha <= 1)); 80 DCHECK(first.width() == second.width()); 81 DCHECK(first.height() == second.height()); 82 DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); 83 DCHECK(first.colorType() == kPMColor_SkColorType); 84 85 // Optimize for case where we won't need to blend anything. 86 static const double alpha_min = 1.0 / 255; 87 static const double alpha_max = 254.0 / 255; 88 if (alpha < alpha_min) 89 return first; 90 else if (alpha > alpha_max) 91 return second; 92 93 SkAutoLockPixels lock_first(first); 94 SkAutoLockPixels lock_second(second); 95 96 SkBitmap blended; 97 blended.allocN32Pixels(first.width(), first.height()); 98 blended.eraseARGB(0, 0, 0, 0); 99 100 double first_alpha = 1 - alpha; 101 102 for (int y = 0; y < first.height(); ++y) { 103 uint32* first_row = first.getAddr32(0, y); 104 uint32* second_row = second.getAddr32(0, y); 105 uint32* dst_row = blended.getAddr32(0, y); 106 107 for (int x = 0; x < first.width(); ++x) { 108 uint32 first_pixel = first_row[x]; 109 uint32 second_pixel = second_row[x]; 110 111 int a = static_cast<int>((SkColorGetA(first_pixel) * first_alpha) + 112 (SkColorGetA(second_pixel) * alpha)); 113 int r = static_cast<int>((SkColorGetR(first_pixel) * first_alpha) + 114 (SkColorGetR(second_pixel) * alpha)); 115 int g = static_cast<int>((SkColorGetG(first_pixel) * first_alpha) + 116 (SkColorGetG(second_pixel) * alpha)); 117 int b = static_cast<int>((SkColorGetB(first_pixel) * first_alpha) + 118 (SkColorGetB(second_pixel) * alpha)); 119 120 dst_row[x] = SkColorSetARGB(a, r, g, b); 121 } 122 } 123 124 return blended; 125 } 126 127 // static 128 SkBitmap SkBitmapOperations::CreateMaskedBitmap(const SkBitmap& rgb, 129 const SkBitmap& alpha) { 130 DCHECK(rgb.width() == alpha.width()); 131 DCHECK(rgb.height() == alpha.height()); 132 DCHECK(rgb.bytesPerPixel() == alpha.bytesPerPixel()); 133 DCHECK(rgb.colorType() == kPMColor_SkColorType); 134 DCHECK(alpha.colorType() == kPMColor_SkColorType); 135 136 SkBitmap masked; 137 masked.allocN32Pixels(rgb.width(), rgb.height()); 138 masked.eraseARGB(0, 0, 0, 0); 139 140 SkAutoLockPixels lock_rgb(rgb); 141 SkAutoLockPixels lock_alpha(alpha); 142 SkAutoLockPixels lock_masked(masked); 143 144 for (int y = 0; y < masked.height(); ++y) { 145 uint32* rgb_row = rgb.getAddr32(0, y); 146 uint32* alpha_row = alpha.getAddr32(0, y); 147 uint32* dst_row = masked.getAddr32(0, y); 148 149 for (int x = 0; x < masked.width(); ++x) { 150 SkColor rgb_pixel = SkUnPreMultiply::PMColorToColor(rgb_row[x]); 151 SkColor alpha_pixel = SkUnPreMultiply::PMColorToColor(alpha_row[x]); 152 int alpha = SkAlphaMul(SkColorGetA(rgb_pixel), 153 SkAlpha255To256(SkColorGetA(alpha_pixel))); 154 int alpha_256 = SkAlpha255To256(alpha); 155 dst_row[x] = SkColorSetARGB(alpha, 156 SkAlphaMul(SkColorGetR(rgb_pixel), alpha_256), 157 SkAlphaMul(SkColorGetG(rgb_pixel), alpha_256), 158 SkAlphaMul(SkColorGetB(rgb_pixel), 159 alpha_256)); 160 } 161 } 162 163 return masked; 164 } 165 166 // static 167 SkBitmap SkBitmapOperations::CreateButtonBackground(SkColor color, 168 const SkBitmap& image, 169 const SkBitmap& mask) { 170 DCHECK(image.colorType() == kPMColor_SkColorType); 171 DCHECK(mask.colorType() == kPMColor_SkColorType); 172 173 SkBitmap background; 174 background.allocN32Pixels(mask.width(), mask.height()); 175 176 double bg_a = SkColorGetA(color); 177 double bg_r = SkColorGetR(color); 178 double bg_g = SkColorGetG(color); 179 double bg_b = SkColorGetB(color); 180 181 SkAutoLockPixels lock_mask(mask); 182 SkAutoLockPixels lock_image(image); 183 SkAutoLockPixels lock_background(background); 184 185 for (int y = 0; y < mask.height(); ++y) { 186 uint32* dst_row = background.getAddr32(0, y); 187 uint32* image_row = image.getAddr32(0, y % image.height()); 188 uint32* mask_row = mask.getAddr32(0, y); 189 190 for (int x = 0; x < mask.width(); ++x) { 191 uint32 image_pixel = image_row[x % image.width()]; 192 193 double img_a = SkColorGetA(image_pixel); 194 double img_r = SkColorGetR(image_pixel); 195 double img_g = SkColorGetG(image_pixel); 196 double img_b = SkColorGetB(image_pixel); 197 198 double img_alpha = static_cast<double>(img_a) / 255.0; 199 double img_inv = 1 - img_alpha; 200 201 double mask_a = static_cast<double>(SkColorGetA(mask_row[x])) / 255.0; 202 203 dst_row[x] = SkColorSetARGB( 204 static_cast<int>(std::min(255.0, bg_a + img_a) * mask_a), 205 static_cast<int>(((bg_r * img_inv) + (img_r * img_alpha)) * mask_a), 206 static_cast<int>(((bg_g * img_inv) + (img_g * img_alpha)) * mask_a), 207 static_cast<int>(((bg_b * img_inv) + (img_b * img_alpha)) * mask_a)); 208 } 209 } 210 211 return background; 212 } 213 214 namespace { 215 namespace HSLShift { 216 217 // TODO(viettrungluu): Some things have yet to be optimized at all. 218 219 // Notes on and conventions used in the following code 220 // 221 // Conventions: 222 // - R, G, B, A = obvious; as variables: |r|, |g|, |b|, |a| (see also below) 223 // - H, S, L = obvious; as variables: |h|, |s|, |l| (see also below) 224 // - variables derived from S, L shift parameters: |sdec| and |sinc| for S 225 // increase and decrease factors, |ldec| and |linc| for L (see also below) 226 // 227 // To try to optimize HSL shifts, we do several things: 228 // - Avoid unpremultiplying (then processing) then premultiplying. This means 229 // that R, G, B values (and also L, but not H and S) should be treated as 230 // having a range of 0..A (where A is alpha). 231 // - Do things in integer/fixed-point. This avoids costly conversions between 232 // floating-point and integer, though I should study the tradeoff more 233 // carefully (presumably, at some point of processing complexity, converting 234 // and processing using simpler floating-point code will begin to win in 235 // performance). Also to be studied is the speed/type of floating point 236 // conversions; see, e.g., <http://www.stereopsis.com/sree/fpu2006.html>. 237 // 238 // Conventions for fixed-point arithmetic 239 // - Each function has a constant denominator (called |den|, which should be a 240 // power of 2), appropriate for the computations done in that function. 241 // - A value |x| is then typically represented by a numerator, named |x_num|, 242 // so that its actual value is |x_num / den| (casting to floating-point 243 // before division). 244 // - To obtain |x_num| from |x|, simply multiply by |den|, i.e., |x_num = x * 245 // den| (casting appropriately). 246 // - When necessary, a value |x| may also be represented as a numerator over 247 // the denominator squared (set |den2 = den * den|). In such a case, the 248 // corresponding variable is called |x_num2| (so that its actual value is 249 // |x_num^2 / den2|. 250 // - The representation of the product of |x| and |y| is be called |x_y_num| if 251 // |x * y == x_y_num / den|, and |xy_num2| if |x * y == x_y_num2 / den2|. In 252 // the latter case, notice that one can calculate |x_y_num2 = x_num * y_num|. 253 254 // Routine used to process a line; typically specialized for specific kinds of 255 // HSL shifts (to optimize). 256 typedef void (*LineProcessor)(const color_utils::HSL&, 257 const SkPMColor*, 258 SkPMColor*, 259 int width); 260 261 enum OperationOnH { kOpHNone = 0, kOpHShift, kNumHOps }; 262 enum OperationOnS { kOpSNone = 0, kOpSDec, kOpSInc, kNumSOps }; 263 enum OperationOnL { kOpLNone = 0, kOpLDec, kOpLInc, kNumLOps }; 264 265 // Epsilon used to judge when shift values are close enough to various critical 266 // values (typically 0.5, which yields a no-op for S and L shifts. 1/256 should 267 // be small enough, but let's play it safe> 268 const double epsilon = 0.0005; 269 270 // Line processor: default/universal (i.e., old-school). 271 void LineProcDefault(const color_utils::HSL& hsl_shift, 272 const SkPMColor* in, 273 SkPMColor* out, 274 int width) { 275 for (int x = 0; x < width; x++) { 276 out[x] = SkPreMultiplyColor(color_utils::HSLShift( 277 SkUnPreMultiply::PMColorToColor(in[x]), hsl_shift)); 278 } 279 } 280 281 // Line processor: no-op (i.e., copy). 282 void LineProcCopy(const color_utils::HSL& hsl_shift, 283 const SkPMColor* in, 284 SkPMColor* out, 285 int width) { 286 DCHECK(hsl_shift.h < 0); 287 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 288 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 289 memcpy(out, in, static_cast<size_t>(width) * sizeof(out[0])); 290 } 291 292 // Line processor: H no-op, S no-op, L decrease. 293 void LineProcHnopSnopLdec(const color_utils::HSL& hsl_shift, 294 const SkPMColor* in, 295 SkPMColor* out, 296 int width) { 297 const uint32_t den = 65536; 298 299 DCHECK(hsl_shift.h < 0); 300 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 301 DCHECK(hsl_shift.l <= 0.5 - HSLShift::epsilon && hsl_shift.l >= 0); 302 303 uint32_t ldec_num = static_cast<uint32_t>(hsl_shift.l * 2 * den); 304 for (int x = 0; x < width; x++) { 305 uint32_t a = SkGetPackedA32(in[x]); 306 uint32_t r = SkGetPackedR32(in[x]); 307 uint32_t g = SkGetPackedG32(in[x]); 308 uint32_t b = SkGetPackedB32(in[x]); 309 r = r * ldec_num / den; 310 g = g * ldec_num / den; 311 b = b * ldec_num / den; 312 out[x] = SkPackARGB32(a, r, g, b); 313 } 314 } 315 316 // Line processor: H no-op, S no-op, L increase. 317 void LineProcHnopSnopLinc(const color_utils::HSL& hsl_shift, 318 const SkPMColor* in, 319 SkPMColor* out, 320 int width) { 321 const uint32_t den = 65536; 322 323 DCHECK(hsl_shift.h < 0); 324 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 325 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 326 327 uint32_t linc_num = static_cast<uint32_t>((hsl_shift.l - 0.5) * 2 * den); 328 for (int x = 0; x < width; x++) { 329 uint32_t a = SkGetPackedA32(in[x]); 330 uint32_t r = SkGetPackedR32(in[x]); 331 uint32_t g = SkGetPackedG32(in[x]); 332 uint32_t b = SkGetPackedB32(in[x]); 333 r += (a - r) * linc_num / den; 334 g += (a - g) * linc_num / den; 335 b += (a - b) * linc_num / den; 336 out[x] = SkPackARGB32(a, r, g, b); 337 } 338 } 339 340 // Saturation changes modifications in RGB 341 // 342 // (Note that as a further complication, the values we deal in are 343 // premultiplied, so R/G/B values must be in the range 0..A. For mathematical 344 // purposes, one may as well use r=R/A, g=G/A, b=B/A. Without loss of 345 // generality, assume that R/G/B values are in the range 0..1.) 346 // 347 // Let Max = max(R,G,B), Min = min(R,G,B), and Med be the median value. Then L = 348 // (Max+Min)/2. If L is to remain constant, Max+Min must also remain constant. 349 // 350 // For H to remain constant, first, the (numerical) order of R/G/B (from 351 // smallest to largest) must remain the same. Second, all the ratios 352 // (R-G)/(Max-Min), (R-B)/(Max-Min), (G-B)/(Max-Min) must remain constant (of 353 // course, if Max = Min, then S = 0 and no saturation change is well-defined, 354 // since H is not well-defined). 355 // 356 // Let C_max be a colour with value Max, C_min be one with value Min, and C_med 357 // the remaining colour. Increasing saturation (to the maximum) is accomplished 358 // by increasing the value of C_max while simultaneously decreasing C_min and 359 // changing C_med so that the ratios are maintained; for the latter, it suffices 360 // to keep (C_med-C_min)/(C_max-C_min) constant (and equal to 361 // (Med-Min)/(Max-Min)). 362 363 // Line processor: H no-op, S decrease, L no-op. 364 void LineProcHnopSdecLnop(const color_utils::HSL& hsl_shift, 365 const SkPMColor* in, 366 SkPMColor* out, 367 int width) { 368 DCHECK(hsl_shift.h < 0); 369 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 370 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 371 372 const int32_t denom = 65536; 373 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 374 for (int x = 0; x < width; x++) { 375 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 376 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 377 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 378 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 379 380 int32_t vmax, vmin; 381 if (r > g) { // This uses 3 compares rather than 4. 382 vmax = std::max(r, b); 383 vmin = std::min(g, b); 384 } else { 385 vmax = std::max(g, b); 386 vmin = std::min(r, b); 387 } 388 389 // Use denom * L to avoid rounding. 390 int32_t denom_l = (vmax + vmin) * (denom / 2); 391 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 392 393 r = (denom_l + r * s_numer - s_numer_l) / denom; 394 g = (denom_l + g * s_numer - s_numer_l) / denom; 395 b = (denom_l + b * s_numer - s_numer_l) / denom; 396 out[x] = SkPackARGB32(a, r, g, b); 397 } 398 } 399 400 // Line processor: H no-op, S decrease, L decrease. 401 void LineProcHnopSdecLdec(const color_utils::HSL& hsl_shift, 402 const SkPMColor* in, 403 SkPMColor* out, 404 int width) { 405 DCHECK(hsl_shift.h < 0); 406 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 407 DCHECK(hsl_shift.l >= 0 && hsl_shift.l <= 0.5 - HSLShift::epsilon); 408 409 // Can't be too big since we need room for denom*denom and a bit for sign. 410 const int32_t denom = 1024; 411 int32_t l_numer = static_cast<int32_t>(hsl_shift.l * 2 * denom); 412 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 413 for (int x = 0; x < width; x++) { 414 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 415 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 416 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 417 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 418 419 int32_t vmax, vmin; 420 if (r > g) { // This uses 3 compares rather than 4. 421 vmax = std::max(r, b); 422 vmin = std::min(g, b); 423 } else { 424 vmax = std::max(g, b); 425 vmin = std::min(r, b); 426 } 427 428 // Use denom * L to avoid rounding. 429 int32_t denom_l = (vmax + vmin) * (denom / 2); 430 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 431 432 r = (denom_l + r * s_numer - s_numer_l) * l_numer / (denom * denom); 433 g = (denom_l + g * s_numer - s_numer_l) * l_numer / (denom * denom); 434 b = (denom_l + b * s_numer - s_numer_l) * l_numer / (denom * denom); 435 out[x] = SkPackARGB32(a, r, g, b); 436 } 437 } 438 439 // Line processor: H no-op, S decrease, L increase. 440 void LineProcHnopSdecLinc(const color_utils::HSL& hsl_shift, 441 const SkPMColor* in, 442 SkPMColor* out, 443 int width) { 444 DCHECK(hsl_shift.h < 0); 445 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 446 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 447 448 // Can't be too big since we need room for denom*denom and a bit for sign. 449 const int32_t denom = 1024; 450 int32_t l_numer = static_cast<int32_t>((hsl_shift.l - 0.5) * 2 * denom); 451 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 452 for (int x = 0; x < width; x++) { 453 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 454 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 455 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 456 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 457 458 int32_t vmax, vmin; 459 if (r > g) { // This uses 3 compares rather than 4. 460 vmax = std::max(r, b); 461 vmin = std::min(g, b); 462 } else { 463 vmax = std::max(g, b); 464 vmin = std::min(r, b); 465 } 466 467 // Use denom * L to avoid rounding. 468 int32_t denom_l = (vmax + vmin) * (denom / 2); 469 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 470 471 r = denom_l + r * s_numer - s_numer_l; 472 g = denom_l + g * s_numer - s_numer_l; 473 b = denom_l + b * s_numer - s_numer_l; 474 475 r = (r * denom + (a * denom - r) * l_numer) / (denom * denom); 476 g = (g * denom + (a * denom - g) * l_numer) / (denom * denom); 477 b = (b * denom + (a * denom - b) * l_numer) / (denom * denom); 478 out[x] = SkPackARGB32(a, r, g, b); 479 } 480 } 481 482 const LineProcessor kLineProcessors[kNumHOps][kNumSOps][kNumLOps] = { 483 { // H: kOpHNone 484 { // S: kOpSNone 485 LineProcCopy, // L: kOpLNone 486 LineProcHnopSnopLdec, // L: kOpLDec 487 LineProcHnopSnopLinc // L: kOpLInc 488 }, 489 { // S: kOpSDec 490 LineProcHnopSdecLnop, // L: kOpLNone 491 LineProcHnopSdecLdec, // L: kOpLDec 492 LineProcHnopSdecLinc // L: kOpLInc 493 }, 494 { // S: kOpSInc 495 LineProcDefault, // L: kOpLNone 496 LineProcDefault, // L: kOpLDec 497 LineProcDefault // L: kOpLInc 498 } 499 }, 500 { // H: kOpHShift 501 { // S: kOpSNone 502 LineProcDefault, // L: kOpLNone 503 LineProcDefault, // L: kOpLDec 504 LineProcDefault // L: kOpLInc 505 }, 506 { // S: kOpSDec 507 LineProcDefault, // L: kOpLNone 508 LineProcDefault, // L: kOpLDec 509 LineProcDefault // L: kOpLInc 510 }, 511 { // S: kOpSInc 512 LineProcDefault, // L: kOpLNone 513 LineProcDefault, // L: kOpLDec 514 LineProcDefault // L: kOpLInc 515 } 516 } 517 }; 518 519 } // namespace HSLShift 520 } // namespace 521 522 // static 523 SkBitmap SkBitmapOperations::CreateHSLShiftedBitmap( 524 const SkBitmap& bitmap, 525 const color_utils::HSL& hsl_shift) { 526 // Default to NOPs. 527 HSLShift::OperationOnH H_op = HSLShift::kOpHNone; 528 HSLShift::OperationOnS S_op = HSLShift::kOpSNone; 529 HSLShift::OperationOnL L_op = HSLShift::kOpLNone; 530 531 if (hsl_shift.h >= 0 && hsl_shift.h <= 1) 532 H_op = HSLShift::kOpHShift; 533 534 // Saturation shift: 0 -> fully desaturate, 0.5 -> NOP, 1 -> fully saturate. 535 if (hsl_shift.s >= 0 && hsl_shift.s <= (0.5 - HSLShift::epsilon)) 536 S_op = HSLShift::kOpSDec; 537 else if (hsl_shift.s >= (0.5 + HSLShift::epsilon)) 538 S_op = HSLShift::kOpSInc; 539 540 // Lightness shift: 0 -> black, 0.5 -> NOP, 1 -> white. 541 if (hsl_shift.l >= 0 && hsl_shift.l <= (0.5 - HSLShift::epsilon)) 542 L_op = HSLShift::kOpLDec; 543 else if (hsl_shift.l >= (0.5 + HSLShift::epsilon)) 544 L_op = HSLShift::kOpLInc; 545 546 HSLShift::LineProcessor line_proc = 547 HSLShift::kLineProcessors[H_op][S_op][L_op]; 548 549 DCHECK(bitmap.empty() == false); 550 DCHECK(bitmap.colorType() == kPMColor_SkColorType); 551 552 SkBitmap shifted; 553 shifted.allocN32Pixels(bitmap.width(), bitmap.height()); 554 shifted.eraseARGB(0, 0, 0, 0); 555 556 SkAutoLockPixels lock_bitmap(bitmap); 557 SkAutoLockPixels lock_shifted(shifted); 558 559 // Loop through the pixels of the original bitmap. 560 for (int y = 0; y < bitmap.height(); ++y) { 561 SkPMColor* pixels = bitmap.getAddr32(0, y); 562 SkPMColor* tinted_pixels = shifted.getAddr32(0, y); 563 564 (*line_proc)(hsl_shift, pixels, tinted_pixels, bitmap.width()); 565 } 566 567 return shifted; 568 } 569 570 // static 571 SkBitmap SkBitmapOperations::CreateTiledBitmap(const SkBitmap& source, 572 int src_x, int src_y, 573 int dst_w, int dst_h) { 574 DCHECK(source.colorType() == kPMColor_SkColorType); 575 576 SkBitmap cropped; 577 cropped.allocN32Pixels(dst_w, dst_h); 578 cropped.eraseARGB(0, 0, 0, 0); 579 580 SkAutoLockPixels lock_source(source); 581 SkAutoLockPixels lock_cropped(cropped); 582 583 // Loop through the pixels of the original bitmap. 584 for (int y = 0; y < dst_h; ++y) { 585 int y_pix = (src_y + y) % source.height(); 586 while (y_pix < 0) 587 y_pix += source.height(); 588 589 uint32* source_row = source.getAddr32(0, y_pix); 590 uint32* dst_row = cropped.getAddr32(0, y); 591 592 for (int x = 0; x < dst_w; ++x) { 593 int x_pix = (src_x + x) % source.width(); 594 while (x_pix < 0) 595 x_pix += source.width(); 596 597 dst_row[x] = source_row[x_pix]; 598 } 599 } 600 601 return cropped; 602 } 603 604 // static 605 SkBitmap SkBitmapOperations::DownsampleByTwoUntilSize(const SkBitmap& bitmap, 606 int min_w, int min_h) { 607 if ((bitmap.width() <= min_w) || (bitmap.height() <= min_h) || 608 (min_w < 0) || (min_h < 0)) 609 return bitmap; 610 611 // Since bitmaps are refcounted, this copy will be fast. 612 SkBitmap current = bitmap; 613 while ((current.width() >= min_w * 2) && (current.height() >= min_h * 2) && 614 (current.width() > 1) && (current.height() > 1)) 615 current = DownsampleByTwo(current); 616 return current; 617 } 618 619 // static 620 SkBitmap SkBitmapOperations::DownsampleByTwo(const SkBitmap& bitmap) { 621 // Handle the nop case. 622 if ((bitmap.width() <= 1) || (bitmap.height() <= 1)) 623 return bitmap; 624 625 SkBitmap result; 626 result.allocN32Pixels((bitmap.width() + 1) / 2, (bitmap.height() + 1) / 2); 627 628 SkAutoLockPixels lock(bitmap); 629 630 const int resultLastX = result.width() - 1; 631 const int srcLastX = bitmap.width() - 1; 632 633 for (int dest_y = 0; dest_y < result.height(); ++dest_y) { 634 const int src_y = dest_y << 1; 635 const SkPMColor* SK_RESTRICT cur_src0 = bitmap.getAddr32(0, src_y); 636 const SkPMColor* SK_RESTRICT cur_src1 = cur_src0; 637 if (src_y + 1 < bitmap.height()) 638 cur_src1 = bitmap.getAddr32(0, src_y + 1); 639 640 SkPMColor* SK_RESTRICT cur_dst = result.getAddr32(0, dest_y); 641 642 for (int dest_x = 0; dest_x <= resultLastX; ++dest_x) { 643 // This code is based on downsampleby2_proc32 in SkBitmap.cpp. It is very 644 // clever in that it does two channels at once: alpha and green ("ag") 645 // and red and blue ("rb"). Each channel gets averaged across 4 pixels 646 // to get the result. 647 int bump_x = (dest_x << 1) < srcLastX; 648 SkPMColor tmp, ag, rb; 649 650 // Top left pixel of the 2x2 block. 651 tmp = cur_src0[0]; 652 ag = (tmp >> 8) & 0xFF00FF; 653 rb = tmp & 0xFF00FF; 654 655 // Top right pixel of the 2x2 block. 656 tmp = cur_src0[bump_x]; 657 ag += (tmp >> 8) & 0xFF00FF; 658 rb += tmp & 0xFF00FF; 659 660 // Bottom left pixel of the 2x2 block. 661 tmp = cur_src1[0]; 662 ag += (tmp >> 8) & 0xFF00FF; 663 rb += tmp & 0xFF00FF; 664 665 // Bottom right pixel of the 2x2 block. 666 tmp = cur_src1[bump_x]; 667 ag += (tmp >> 8) & 0xFF00FF; 668 rb += tmp & 0xFF00FF; 669 670 // Put the channels back together, dividing each by 4 to get the average. 671 // |ag| has the alpha and green channels shifted right by 8 bits from 672 // there they should end up, so shifting left by 6 gives them in the 673 // correct position divided by 4. 674 *cur_dst++ = ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); 675 676 cur_src0 += 2; 677 cur_src1 += 2; 678 } 679 } 680 681 return result; 682 } 683 684 // static 685 SkBitmap SkBitmapOperations::UnPreMultiply(const SkBitmap& bitmap) { 686 if (bitmap.isNull()) 687 return bitmap; 688 if (bitmap.isOpaque()) 689 return bitmap; 690 691 SkImageInfo info = bitmap.info(); 692 info.fAlphaType = kOpaque_SkAlphaType; 693 SkBitmap opaque_bitmap; 694 opaque_bitmap.allocPixels(info); 695 696 { 697 SkAutoLockPixels bitmap_lock(bitmap); 698 SkAutoLockPixels opaque_bitmap_lock(opaque_bitmap); 699 for (int y = 0; y < opaque_bitmap.height(); y++) { 700 for (int x = 0; x < opaque_bitmap.width(); x++) { 701 uint32 src_pixel = *bitmap.getAddr32(x, y); 702 uint32* dst_pixel = opaque_bitmap.getAddr32(x, y); 703 SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(src_pixel); 704 *dst_pixel = unmultiplied; 705 } 706 } 707 } 708 709 return opaque_bitmap; 710 } 711 712 // static 713 SkBitmap SkBitmapOperations::CreateTransposedBitmap(const SkBitmap& image) { 714 DCHECK(image.colorType() == kPMColor_SkColorType); 715 716 SkBitmap transposed; 717 transposed.allocN32Pixels(image.height(), image.width()); 718 719 SkAutoLockPixels lock_image(image); 720 SkAutoLockPixels lock_transposed(transposed); 721 722 for (int y = 0; y < image.height(); ++y) { 723 uint32* image_row = image.getAddr32(0, y); 724 for (int x = 0; x < image.width(); ++x) { 725 uint32* dst = transposed.getAddr32(y, x); 726 *dst = image_row[x]; 727 } 728 } 729 730 return transposed; 731 } 732 733 // static 734 SkBitmap SkBitmapOperations::CreateColorMask(const SkBitmap& bitmap, 735 SkColor c) { 736 DCHECK(bitmap.colorType() == kPMColor_SkColorType); 737 738 SkBitmap color_mask; 739 color_mask.allocN32Pixels(bitmap.width(), bitmap.height()); 740 color_mask.eraseARGB(0, 0, 0, 0); 741 742 SkCanvas canvas(color_mask); 743 744 skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef( 745 SkColorFilter::CreateModeFilter(c, SkXfermode::kSrcIn_Mode)); 746 SkPaint paint; 747 paint.setColorFilter(color_filter.get()); 748 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0), &paint); 749 return color_mask; 750 } 751 752 // static 753 SkBitmap SkBitmapOperations::CreateDropShadow( 754 const SkBitmap& bitmap, 755 const gfx::ShadowValues& shadows) { 756 DCHECK(bitmap.colorType() == kPMColor_SkColorType); 757 758 // Shadow margin insets are negative values because they grow outside. 759 // Negate them here as grow direction is not important and only pixel value 760 // is of interest here. 761 gfx::Insets shadow_margin = -gfx::ShadowValue::GetMargin(shadows); 762 763 SkBitmap image_with_shadow; 764 image_with_shadow.allocN32Pixels(bitmap.width() + shadow_margin.width(), 765 bitmap.height() + shadow_margin.height()); 766 image_with_shadow.eraseARGB(0, 0, 0, 0); 767 768 SkCanvas canvas(image_with_shadow); 769 canvas.translate(SkIntToScalar(shadow_margin.left()), 770 SkIntToScalar(shadow_margin.top())); 771 772 SkPaint paint; 773 for (size_t i = 0; i < shadows.size(); ++i) { 774 const gfx::ShadowValue& shadow = shadows[i]; 775 SkBitmap shadow_image = SkBitmapOperations::CreateColorMask(bitmap, 776 shadow.color()); 777 778 skia::RefPtr<SkBlurImageFilter> filter = 779 skia::AdoptRef(SkBlurImageFilter::Create( 780 SkDoubleToScalar(shadow.blur()), SkDoubleToScalar(shadow.blur()))); 781 paint.setImageFilter(filter.get()); 782 783 canvas.saveLayer(0, &paint); 784 canvas.drawBitmap(shadow_image, 785 SkIntToScalar(shadow.x()), 786 SkIntToScalar(shadow.y())); 787 canvas.restore(); 788 } 789 790 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0)); 791 return image_with_shadow; 792 } 793 794 // static 795 SkBitmap SkBitmapOperations::Rotate(const SkBitmap& source, 796 RotationAmount rotation) { 797 SkBitmap result; 798 SkScalar angle = SkFloatToScalar(0.0f); 799 800 switch (rotation) { 801 case ROTATION_90_CW: 802 angle = SkFloatToScalar(90.0f); 803 result.setConfig( 804 SkBitmap::kARGB_8888_Config, source.height(), source.width()); 805 break; 806 case ROTATION_180_CW: 807 angle = SkFloatToScalar(180.0f); 808 result.setConfig( 809 SkBitmap::kARGB_8888_Config, source.width(), source.height()); 810 break; 811 case ROTATION_270_CW: 812 angle = SkFloatToScalar(270.0f); 813 result.setConfig( 814 SkBitmap::kARGB_8888_Config, source.height(), source.width()); 815 break; 816 } 817 result.allocPixels(); 818 SkCanvas canvas(result); 819 canvas.clear(SkColorSetARGB(0, 0, 0, 0)); 820 821 canvas.translate(SkFloatToScalar(result.width() * 0.5f), 822 SkFloatToScalar(result.height() * 0.5f)); 823 canvas.rotate(angle); 824 canvas.translate(-SkFloatToScalar(source.width() * 0.5f), 825 -SkFloatToScalar(source.height() * 0.5f)); 826 canvas.drawBitmap(source, 0, 0); 827 canvas.flush(); 828 829 return result; 830 } 831
