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() == kN32_SkColorType); 25 26 SkAutoLockPixels lock_image(image); 27 28 SkBitmap inverted; 29 inverted.allocN32Pixels(image.width(), image.height()); 30 31 for (int y = 0; y < image.height(); ++y) { 32 uint32* image_row = image.getAddr32(0, y); 33 uint32* dst_row = inverted.getAddr32(0, y); 34 35 for (int x = 0; x < image.width(); ++x) { 36 uint32 image_pixel = image_row[x]; 37 dst_row[x] = (image_pixel & 0xFF000000) | 38 (0x00FFFFFF - (image_pixel & 0x00FFFFFF)); 39 } 40 } 41 42 return inverted; 43 } 44 45 // static 46 SkBitmap SkBitmapOperations::CreateBlendedBitmap(const SkBitmap& first, 47 const SkBitmap& second, 48 double alpha) { 49 DCHECK((alpha >= 0) && (alpha <= 1)); 50 DCHECK(first.width() == second.width()); 51 DCHECK(first.height() == second.height()); 52 DCHECK(first.bytesPerPixel() == second.bytesPerPixel()); 53 DCHECK(first.colorType() == kN32_SkColorType); 54 55 // Optimize for case where we won't need to blend anything. 56 static const double alpha_min = 1.0 / 255; 57 static const double alpha_max = 254.0 / 255; 58 if (alpha < alpha_min) 59 return first; 60 else if (alpha > alpha_max) 61 return second; 62 63 SkAutoLockPixels lock_first(first); 64 SkAutoLockPixels lock_second(second); 65 66 SkBitmap blended; 67 blended.allocN32Pixels(first.width(), first.height()); 68 69 double first_alpha = 1 - alpha; 70 71 for (int y = 0; y < first.height(); ++y) { 72 uint32* first_row = first.getAddr32(0, y); 73 uint32* second_row = second.getAddr32(0, y); 74 uint32* dst_row = blended.getAddr32(0, y); 75 76 for (int x = 0; x < first.width(); ++x) { 77 uint32 first_pixel = first_row[x]; 78 uint32 second_pixel = second_row[x]; 79 80 int a = static_cast<int>((SkColorGetA(first_pixel) * first_alpha) + 81 (SkColorGetA(second_pixel) * alpha)); 82 int r = static_cast<int>((SkColorGetR(first_pixel) * first_alpha) + 83 (SkColorGetR(second_pixel) * alpha)); 84 int g = static_cast<int>((SkColorGetG(first_pixel) * first_alpha) + 85 (SkColorGetG(second_pixel) * alpha)); 86 int b = static_cast<int>((SkColorGetB(first_pixel) * first_alpha) + 87 (SkColorGetB(second_pixel) * alpha)); 88 89 dst_row[x] = SkColorSetARGB(a, r, g, b); 90 } 91 } 92 93 return blended; 94 } 95 96 // static 97 SkBitmap SkBitmapOperations::CreateMaskedBitmap(const SkBitmap& rgb, 98 const SkBitmap& alpha) { 99 DCHECK(rgb.width() == alpha.width()); 100 DCHECK(rgb.height() == alpha.height()); 101 DCHECK(rgb.bytesPerPixel() == alpha.bytesPerPixel()); 102 DCHECK(rgb.colorType() == kN32_SkColorType); 103 DCHECK(alpha.colorType() == kN32_SkColorType); 104 105 SkBitmap masked; 106 masked.allocN32Pixels(rgb.width(), rgb.height()); 107 108 SkAutoLockPixels lock_rgb(rgb); 109 SkAutoLockPixels lock_alpha(alpha); 110 SkAutoLockPixels lock_masked(masked); 111 112 for (int y = 0; y < masked.height(); ++y) { 113 uint32* rgb_row = rgb.getAddr32(0, y); 114 uint32* alpha_row = alpha.getAddr32(0, y); 115 uint32* dst_row = masked.getAddr32(0, y); 116 117 for (int x = 0; x < masked.width(); ++x) { 118 SkColor rgb_pixel = SkUnPreMultiply::PMColorToColor(rgb_row[x]); 119 SkColor alpha_pixel = SkUnPreMultiply::PMColorToColor(alpha_row[x]); 120 int alpha = SkAlphaMul(SkColorGetA(rgb_pixel), 121 SkAlpha255To256(SkColorGetA(alpha_pixel))); 122 int alpha_256 = SkAlpha255To256(alpha); 123 dst_row[x] = SkColorSetARGB(alpha, 124 SkAlphaMul(SkColorGetR(rgb_pixel), alpha_256), 125 SkAlphaMul(SkColorGetG(rgb_pixel), alpha_256), 126 SkAlphaMul(SkColorGetB(rgb_pixel), 127 alpha_256)); 128 } 129 } 130 131 return masked; 132 } 133 134 // static 135 SkBitmap SkBitmapOperations::CreateButtonBackground(SkColor color, 136 const SkBitmap& image, 137 const SkBitmap& mask) { 138 DCHECK(image.colorType() == kN32_SkColorType); 139 DCHECK(mask.colorType() == kN32_SkColorType); 140 141 SkBitmap background; 142 background.allocN32Pixels(mask.width(), mask.height()); 143 144 double bg_a = SkColorGetA(color); 145 double bg_r = SkColorGetR(color); 146 double bg_g = SkColorGetG(color); 147 double bg_b = SkColorGetB(color); 148 149 SkAutoLockPixels lock_mask(mask); 150 SkAutoLockPixels lock_image(image); 151 SkAutoLockPixels lock_background(background); 152 153 for (int y = 0; y < mask.height(); ++y) { 154 uint32* dst_row = background.getAddr32(0, y); 155 uint32* image_row = image.getAddr32(0, y % image.height()); 156 uint32* mask_row = mask.getAddr32(0, y); 157 158 for (int x = 0; x < mask.width(); ++x) { 159 uint32 image_pixel = image_row[x % image.width()]; 160 161 double img_a = SkColorGetA(image_pixel); 162 double img_r = SkColorGetR(image_pixel); 163 double img_g = SkColorGetG(image_pixel); 164 double img_b = SkColorGetB(image_pixel); 165 166 double img_alpha = static_cast<double>(img_a) / 255.0; 167 double img_inv = 1 - img_alpha; 168 169 double mask_a = static_cast<double>(SkColorGetA(mask_row[x])) / 255.0; 170 171 dst_row[x] = SkColorSetARGB( 172 static_cast<int>(std::min(255.0, bg_a + img_a) * mask_a), 173 static_cast<int>(((bg_r * img_inv) + (img_r * img_alpha)) * mask_a), 174 static_cast<int>(((bg_g * img_inv) + (img_g * img_alpha)) * mask_a), 175 static_cast<int>(((bg_b * img_inv) + (img_b * img_alpha)) * mask_a)); 176 } 177 } 178 179 return background; 180 } 181 182 namespace { 183 namespace HSLShift { 184 185 // TODO(viettrungluu): Some things have yet to be optimized at all. 186 187 // Notes on and conventions used in the following code 188 // 189 // Conventions: 190 // - R, G, B, A = obvious; as variables: |r|, |g|, |b|, |a| (see also below) 191 // - H, S, L = obvious; as variables: |h|, |s|, |l| (see also below) 192 // - variables derived from S, L shift parameters: |sdec| and |sinc| for S 193 // increase and decrease factors, |ldec| and |linc| for L (see also below) 194 // 195 // To try to optimize HSL shifts, we do several things: 196 // - Avoid unpremultiplying (then processing) then premultiplying. This means 197 // that R, G, B values (and also L, but not H and S) should be treated as 198 // having a range of 0..A (where A is alpha). 199 // - Do things in integer/fixed-point. This avoids costly conversions between 200 // floating-point and integer, though I should study the tradeoff more 201 // carefully (presumably, at some point of processing complexity, converting 202 // and processing using simpler floating-point code will begin to win in 203 // performance). Also to be studied is the speed/type of floating point 204 // conversions; see, e.g., <http://www.stereopsis.com/sree/fpu2006.html>. 205 // 206 // Conventions for fixed-point arithmetic 207 // - Each function has a constant denominator (called |den|, which should be a 208 // power of 2), appropriate for the computations done in that function. 209 // - A value |x| is then typically represented by a numerator, named |x_num|, 210 // so that its actual value is |x_num / den| (casting to floating-point 211 // before division). 212 // - To obtain |x_num| from |x|, simply multiply by |den|, i.e., |x_num = x * 213 // den| (casting appropriately). 214 // - When necessary, a value |x| may also be represented as a numerator over 215 // the denominator squared (set |den2 = den * den|). In such a case, the 216 // corresponding variable is called |x_num2| (so that its actual value is 217 // |x_num^2 / den2|. 218 // - The representation of the product of |x| and |y| is be called |x_y_num| if 219 // |x * y == x_y_num / den|, and |xy_num2| if |x * y == x_y_num2 / den2|. In 220 // the latter case, notice that one can calculate |x_y_num2 = x_num * y_num|. 221 222 // Routine used to process a line; typically specialized for specific kinds of 223 // HSL shifts (to optimize). 224 typedef void (*LineProcessor)(const color_utils::HSL&, 225 const SkPMColor*, 226 SkPMColor*, 227 int width); 228 229 enum OperationOnH { kOpHNone = 0, kOpHShift, kNumHOps }; 230 enum OperationOnS { kOpSNone = 0, kOpSDec, kOpSInc, kNumSOps }; 231 enum OperationOnL { kOpLNone = 0, kOpLDec, kOpLInc, kNumLOps }; 232 233 // Epsilon used to judge when shift values are close enough to various critical 234 // values (typically 0.5, which yields a no-op for S and L shifts. 1/256 should 235 // be small enough, but let's play it safe> 236 const double epsilon = 0.0005; 237 238 // Line processor: default/universal (i.e., old-school). 239 void LineProcDefault(const color_utils::HSL& hsl_shift, 240 const SkPMColor* in, 241 SkPMColor* out, 242 int width) { 243 for (int x = 0; x < width; x++) { 244 out[x] = SkPreMultiplyColor(color_utils::HSLShift( 245 SkUnPreMultiply::PMColorToColor(in[x]), hsl_shift)); 246 } 247 } 248 249 // Line processor: no-op (i.e., copy). 250 void LineProcCopy(const color_utils::HSL& hsl_shift, 251 const SkPMColor* in, 252 SkPMColor* out, 253 int width) { 254 DCHECK(hsl_shift.h < 0); 255 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 256 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 257 memcpy(out, in, static_cast<size_t>(width) * sizeof(out[0])); 258 } 259 260 // Line processor: H no-op, S no-op, L decrease. 261 void LineProcHnopSnopLdec(const color_utils::HSL& hsl_shift, 262 const SkPMColor* in, 263 SkPMColor* out, 264 int width) { 265 const uint32_t den = 65536; 266 267 DCHECK(hsl_shift.h < 0); 268 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 269 DCHECK(hsl_shift.l <= 0.5 - HSLShift::epsilon && hsl_shift.l >= 0); 270 271 uint32_t ldec_num = static_cast<uint32_t>(hsl_shift.l * 2 * den); 272 for (int x = 0; x < width; x++) { 273 uint32_t a = SkGetPackedA32(in[x]); 274 uint32_t r = SkGetPackedR32(in[x]); 275 uint32_t g = SkGetPackedG32(in[x]); 276 uint32_t b = SkGetPackedB32(in[x]); 277 r = r * ldec_num / den; 278 g = g * ldec_num / den; 279 b = b * ldec_num / den; 280 out[x] = SkPackARGB32(a, r, g, b); 281 } 282 } 283 284 // Line processor: H no-op, S no-op, L increase. 285 void LineProcHnopSnopLinc(const color_utils::HSL& hsl_shift, 286 const SkPMColor* in, 287 SkPMColor* out, 288 int width) { 289 const uint32_t den = 65536; 290 291 DCHECK(hsl_shift.h < 0); 292 DCHECK(hsl_shift.s < 0 || fabs(hsl_shift.s - 0.5) < HSLShift::epsilon); 293 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 294 295 uint32_t linc_num = static_cast<uint32_t>((hsl_shift.l - 0.5) * 2 * den); 296 for (int x = 0; x < width; x++) { 297 uint32_t a = SkGetPackedA32(in[x]); 298 uint32_t r = SkGetPackedR32(in[x]); 299 uint32_t g = SkGetPackedG32(in[x]); 300 uint32_t b = SkGetPackedB32(in[x]); 301 r += (a - r) * linc_num / den; 302 g += (a - g) * linc_num / den; 303 b += (a - b) * linc_num / den; 304 out[x] = SkPackARGB32(a, r, g, b); 305 } 306 } 307 308 // Saturation changes modifications in RGB 309 // 310 // (Note that as a further complication, the values we deal in are 311 // premultiplied, so R/G/B values must be in the range 0..A. For mathematical 312 // purposes, one may as well use r=R/A, g=G/A, b=B/A. Without loss of 313 // generality, assume that R/G/B values are in the range 0..1.) 314 // 315 // Let Max = max(R,G,B), Min = min(R,G,B), and Med be the median value. Then L = 316 // (Max+Min)/2. If L is to remain constant, Max+Min must also remain constant. 317 // 318 // For H to remain constant, first, the (numerical) order of R/G/B (from 319 // smallest to largest) must remain the same. Second, all the ratios 320 // (R-G)/(Max-Min), (R-B)/(Max-Min), (G-B)/(Max-Min) must remain constant (of 321 // course, if Max = Min, then S = 0 and no saturation change is well-defined, 322 // since H is not well-defined). 323 // 324 // Let C_max be a colour with value Max, C_min be one with value Min, and C_med 325 // the remaining colour. Increasing saturation (to the maximum) is accomplished 326 // by increasing the value of C_max while simultaneously decreasing C_min and 327 // changing C_med so that the ratios are maintained; for the latter, it suffices 328 // to keep (C_med-C_min)/(C_max-C_min) constant (and equal to 329 // (Med-Min)/(Max-Min)). 330 331 // Line processor: H no-op, S decrease, L no-op. 332 void LineProcHnopSdecLnop(const color_utils::HSL& hsl_shift, 333 const SkPMColor* in, 334 SkPMColor* out, 335 int width) { 336 DCHECK(hsl_shift.h < 0); 337 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 338 DCHECK(hsl_shift.l < 0 || fabs(hsl_shift.l - 0.5) < HSLShift::epsilon); 339 340 const int32_t denom = 65536; 341 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 342 for (int x = 0; x < width; x++) { 343 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 344 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 345 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 346 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 347 348 int32_t vmax, vmin; 349 if (r > g) { // This uses 3 compares rather than 4. 350 vmax = std::max(r, b); 351 vmin = std::min(g, b); 352 } else { 353 vmax = std::max(g, b); 354 vmin = std::min(r, b); 355 } 356 357 // Use denom * L to avoid rounding. 358 int32_t denom_l = (vmax + vmin) * (denom / 2); 359 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 360 361 r = (denom_l + r * s_numer - s_numer_l) / denom; 362 g = (denom_l + g * s_numer - s_numer_l) / denom; 363 b = (denom_l + b * s_numer - s_numer_l) / denom; 364 out[x] = SkPackARGB32(a, r, g, b); 365 } 366 } 367 368 // Line processor: H no-op, S decrease, L decrease. 369 void LineProcHnopSdecLdec(const color_utils::HSL& hsl_shift, 370 const SkPMColor* in, 371 SkPMColor* out, 372 int width) { 373 DCHECK(hsl_shift.h < 0); 374 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 375 DCHECK(hsl_shift.l >= 0 && hsl_shift.l <= 0.5 - HSLShift::epsilon); 376 377 // Can't be too big since we need room for denom*denom and a bit for sign. 378 const int32_t denom = 1024; 379 int32_t l_numer = static_cast<int32_t>(hsl_shift.l * 2 * denom); 380 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 381 for (int x = 0; x < width; x++) { 382 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 383 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 384 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 385 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 386 387 int32_t vmax, vmin; 388 if (r > g) { // This uses 3 compares rather than 4. 389 vmax = std::max(r, b); 390 vmin = std::min(g, b); 391 } else { 392 vmax = std::max(g, b); 393 vmin = std::min(r, b); 394 } 395 396 // Use denom * L to avoid rounding. 397 int32_t denom_l = (vmax + vmin) * (denom / 2); 398 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 399 400 r = (denom_l + r * s_numer - s_numer_l) * l_numer / (denom * denom); 401 g = (denom_l + g * s_numer - s_numer_l) * l_numer / (denom * denom); 402 b = (denom_l + b * s_numer - s_numer_l) * l_numer / (denom * denom); 403 out[x] = SkPackARGB32(a, r, g, b); 404 } 405 } 406 407 // Line processor: H no-op, S decrease, L increase. 408 void LineProcHnopSdecLinc(const color_utils::HSL& hsl_shift, 409 const SkPMColor* in, 410 SkPMColor* out, 411 int width) { 412 DCHECK(hsl_shift.h < 0); 413 DCHECK(hsl_shift.s >= 0 && hsl_shift.s <= 0.5 - HSLShift::epsilon); 414 DCHECK(hsl_shift.l >= 0.5 + HSLShift::epsilon && hsl_shift.l <= 1); 415 416 // Can't be too big since we need room for denom*denom and a bit for sign. 417 const int32_t denom = 1024; 418 int32_t l_numer = static_cast<int32_t>((hsl_shift.l - 0.5) * 2 * denom); 419 int32_t s_numer = static_cast<int32_t>(hsl_shift.s * 2 * denom); 420 for (int x = 0; x < width; x++) { 421 int32_t a = static_cast<int32_t>(SkGetPackedA32(in[x])); 422 int32_t r = static_cast<int32_t>(SkGetPackedR32(in[x])); 423 int32_t g = static_cast<int32_t>(SkGetPackedG32(in[x])); 424 int32_t b = static_cast<int32_t>(SkGetPackedB32(in[x])); 425 426 int32_t vmax, vmin; 427 if (r > g) { // This uses 3 compares rather than 4. 428 vmax = std::max(r, b); 429 vmin = std::min(g, b); 430 } else { 431 vmax = std::max(g, b); 432 vmin = std::min(r, b); 433 } 434 435 // Use denom * L to avoid rounding. 436 int32_t denom_l = (vmax + vmin) * (denom / 2); 437 int32_t s_numer_l = (vmax + vmin) * s_numer / 2; 438 439 r = denom_l + r * s_numer - s_numer_l; 440 g = denom_l + g * s_numer - s_numer_l; 441 b = denom_l + b * s_numer - s_numer_l; 442 443 r = (r * denom + (a * denom - r) * l_numer) / (denom * denom); 444 g = (g * denom + (a * denom - g) * l_numer) / (denom * denom); 445 b = (b * denom + (a * denom - b) * l_numer) / (denom * denom); 446 out[x] = SkPackARGB32(a, r, g, b); 447 } 448 } 449 450 const LineProcessor kLineProcessors[kNumHOps][kNumSOps][kNumLOps] = { 451 { // H: kOpHNone 452 { // S: kOpSNone 453 LineProcCopy, // L: kOpLNone 454 LineProcHnopSnopLdec, // L: kOpLDec 455 LineProcHnopSnopLinc // L: kOpLInc 456 }, 457 { // S: kOpSDec 458 LineProcHnopSdecLnop, // L: kOpLNone 459 LineProcHnopSdecLdec, // L: kOpLDec 460 LineProcHnopSdecLinc // L: kOpLInc 461 }, 462 { // S: kOpSInc 463 LineProcDefault, // L: kOpLNone 464 LineProcDefault, // L: kOpLDec 465 LineProcDefault // L: kOpLInc 466 } 467 }, 468 { // H: kOpHShift 469 { // S: kOpSNone 470 LineProcDefault, // L: kOpLNone 471 LineProcDefault, // L: kOpLDec 472 LineProcDefault // L: kOpLInc 473 }, 474 { // S: kOpSDec 475 LineProcDefault, // L: kOpLNone 476 LineProcDefault, // L: kOpLDec 477 LineProcDefault // L: kOpLInc 478 }, 479 { // S: kOpSInc 480 LineProcDefault, // L: kOpLNone 481 LineProcDefault, // L: kOpLDec 482 LineProcDefault // L: kOpLInc 483 } 484 } 485 }; 486 487 } // namespace HSLShift 488 } // namespace 489 490 // static 491 SkBitmap SkBitmapOperations::CreateHSLShiftedBitmap( 492 const SkBitmap& bitmap, 493 const color_utils::HSL& hsl_shift) { 494 // Default to NOPs. 495 HSLShift::OperationOnH H_op = HSLShift::kOpHNone; 496 HSLShift::OperationOnS S_op = HSLShift::kOpSNone; 497 HSLShift::OperationOnL L_op = HSLShift::kOpLNone; 498 499 if (hsl_shift.h >= 0 && hsl_shift.h <= 1) 500 H_op = HSLShift::kOpHShift; 501 502 // Saturation shift: 0 -> fully desaturate, 0.5 -> NOP, 1 -> fully saturate. 503 if (hsl_shift.s >= 0 && hsl_shift.s <= (0.5 - HSLShift::epsilon)) 504 S_op = HSLShift::kOpSDec; 505 else if (hsl_shift.s >= (0.5 + HSLShift::epsilon)) 506 S_op = HSLShift::kOpSInc; 507 508 // Lightness shift: 0 -> black, 0.5 -> NOP, 1 -> white. 509 if (hsl_shift.l >= 0 && hsl_shift.l <= (0.5 - HSLShift::epsilon)) 510 L_op = HSLShift::kOpLDec; 511 else if (hsl_shift.l >= (0.5 + HSLShift::epsilon)) 512 L_op = HSLShift::kOpLInc; 513 514 HSLShift::LineProcessor line_proc = 515 HSLShift::kLineProcessors[H_op][S_op][L_op]; 516 517 DCHECK(bitmap.empty() == false); 518 DCHECK(bitmap.colorType() == kN32_SkColorType); 519 520 SkBitmap shifted; 521 shifted.allocN32Pixels(bitmap.width(), bitmap.height()); 522 523 SkAutoLockPixels lock_bitmap(bitmap); 524 SkAutoLockPixels lock_shifted(shifted); 525 526 // Loop through the pixels of the original bitmap. 527 for (int y = 0; y < bitmap.height(); ++y) { 528 SkPMColor* pixels = bitmap.getAddr32(0, y); 529 SkPMColor* tinted_pixels = shifted.getAddr32(0, y); 530 531 (*line_proc)(hsl_shift, pixels, tinted_pixels, bitmap.width()); 532 } 533 534 return shifted; 535 } 536 537 // static 538 SkBitmap SkBitmapOperations::CreateTiledBitmap(const SkBitmap& source, 539 int src_x, int src_y, 540 int dst_w, int dst_h) { 541 DCHECK(source.colorType() == kN32_SkColorType); 542 543 SkBitmap cropped; 544 cropped.allocN32Pixels(dst_w, dst_h); 545 546 SkAutoLockPixels lock_source(source); 547 SkAutoLockPixels lock_cropped(cropped); 548 549 // Loop through the pixels of the original bitmap. 550 for (int y = 0; y < dst_h; ++y) { 551 int y_pix = (src_y + y) % source.height(); 552 while (y_pix < 0) 553 y_pix += source.height(); 554 555 uint32* source_row = source.getAddr32(0, y_pix); 556 uint32* dst_row = cropped.getAddr32(0, y); 557 558 for (int x = 0; x < dst_w; ++x) { 559 int x_pix = (src_x + x) % source.width(); 560 while (x_pix < 0) 561 x_pix += source.width(); 562 563 dst_row[x] = source_row[x_pix]; 564 } 565 } 566 567 return cropped; 568 } 569 570 // static 571 SkBitmap SkBitmapOperations::DownsampleByTwoUntilSize(const SkBitmap& bitmap, 572 int min_w, int min_h) { 573 if ((bitmap.width() <= min_w) || (bitmap.height() <= min_h) || 574 (min_w < 0) || (min_h < 0)) 575 return bitmap; 576 577 // Since bitmaps are refcounted, this copy will be fast. 578 SkBitmap current = bitmap; 579 while ((current.width() >= min_w * 2) && (current.height() >= min_h * 2) && 580 (current.width() > 1) && (current.height() > 1)) 581 current = DownsampleByTwo(current); 582 return current; 583 } 584 585 // static 586 SkBitmap SkBitmapOperations::DownsampleByTwo(const SkBitmap& bitmap) { 587 // Handle the nop case. 588 if ((bitmap.width() <= 1) || (bitmap.height() <= 1)) 589 return bitmap; 590 591 SkBitmap result; 592 result.allocN32Pixels((bitmap.width() + 1) / 2, (bitmap.height() + 1) / 2); 593 594 SkAutoLockPixels lock(bitmap); 595 596 const int resultLastX = result.width() - 1; 597 const int srcLastX = bitmap.width() - 1; 598 599 for (int dest_y = 0; dest_y < result.height(); ++dest_y) { 600 const int src_y = dest_y << 1; 601 const SkPMColor* SK_RESTRICT cur_src0 = bitmap.getAddr32(0, src_y); 602 const SkPMColor* SK_RESTRICT cur_src1 = cur_src0; 603 if (src_y + 1 < bitmap.height()) 604 cur_src1 = bitmap.getAddr32(0, src_y + 1); 605 606 SkPMColor* SK_RESTRICT cur_dst = result.getAddr32(0, dest_y); 607 608 for (int dest_x = 0; dest_x <= resultLastX; ++dest_x) { 609 // This code is based on downsampleby2_proc32 in SkBitmap.cpp. It is very 610 // clever in that it does two channels at once: alpha and green ("ag") 611 // and red and blue ("rb"). Each channel gets averaged across 4 pixels 612 // to get the result. 613 int bump_x = (dest_x << 1) < srcLastX; 614 SkPMColor tmp, ag, rb; 615 616 // Top left pixel of the 2x2 block. 617 tmp = cur_src0[0]; 618 ag = (tmp >> 8) & 0xFF00FF; 619 rb = tmp & 0xFF00FF; 620 621 // Top right pixel of the 2x2 block. 622 tmp = cur_src0[bump_x]; 623 ag += (tmp >> 8) & 0xFF00FF; 624 rb += tmp & 0xFF00FF; 625 626 // Bottom left pixel of the 2x2 block. 627 tmp = cur_src1[0]; 628 ag += (tmp >> 8) & 0xFF00FF; 629 rb += tmp & 0xFF00FF; 630 631 // Bottom right pixel of the 2x2 block. 632 tmp = cur_src1[bump_x]; 633 ag += (tmp >> 8) & 0xFF00FF; 634 rb += tmp & 0xFF00FF; 635 636 // Put the channels back together, dividing each by 4 to get the average. 637 // |ag| has the alpha and green channels shifted right by 8 bits from 638 // there they should end up, so shifting left by 6 gives them in the 639 // correct position divided by 4. 640 *cur_dst++ = ((rb >> 2) & 0xFF00FF) | ((ag << 6) & 0xFF00FF00); 641 642 cur_src0 += 2; 643 cur_src1 += 2; 644 } 645 } 646 647 return result; 648 } 649 650 // static 651 SkBitmap SkBitmapOperations::UnPreMultiply(const SkBitmap& bitmap) { 652 if (bitmap.isNull()) 653 return bitmap; 654 if (bitmap.isOpaque()) 655 return bitmap; 656 657 SkImageInfo info = bitmap.info(); 658 info.fAlphaType = kOpaque_SkAlphaType; 659 SkBitmap opaque_bitmap; 660 opaque_bitmap.allocPixels(info); 661 662 { 663 SkAutoLockPixels bitmap_lock(bitmap); 664 SkAutoLockPixels opaque_bitmap_lock(opaque_bitmap); 665 for (int y = 0; y < opaque_bitmap.height(); y++) { 666 for (int x = 0; x < opaque_bitmap.width(); x++) { 667 uint32 src_pixel = *bitmap.getAddr32(x, y); 668 uint32* dst_pixel = opaque_bitmap.getAddr32(x, y); 669 SkColor unmultiplied = SkUnPreMultiply::PMColorToColor(src_pixel); 670 *dst_pixel = unmultiplied; 671 } 672 } 673 } 674 675 return opaque_bitmap; 676 } 677 678 // static 679 SkBitmap SkBitmapOperations::CreateTransposedBitmap(const SkBitmap& image) { 680 DCHECK(image.colorType() == kN32_SkColorType); 681 682 SkBitmap transposed; 683 transposed.allocN32Pixels(image.height(), image.width()); 684 685 SkAutoLockPixels lock_image(image); 686 SkAutoLockPixels lock_transposed(transposed); 687 688 for (int y = 0; y < image.height(); ++y) { 689 uint32* image_row = image.getAddr32(0, y); 690 for (int x = 0; x < image.width(); ++x) { 691 uint32* dst = transposed.getAddr32(y, x); 692 *dst = image_row[x]; 693 } 694 } 695 696 return transposed; 697 } 698 699 // static 700 SkBitmap SkBitmapOperations::CreateColorMask(const SkBitmap& bitmap, 701 SkColor c) { 702 DCHECK(bitmap.colorType() == kN32_SkColorType); 703 704 SkBitmap color_mask; 705 color_mask.allocN32Pixels(bitmap.width(), bitmap.height()); 706 color_mask.eraseARGB(0, 0, 0, 0); 707 708 SkCanvas canvas(color_mask); 709 710 skia::RefPtr<SkColorFilter> color_filter = skia::AdoptRef( 711 SkColorFilter::CreateModeFilter(c, SkXfermode::kSrcIn_Mode)); 712 SkPaint paint; 713 paint.setColorFilter(color_filter.get()); 714 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0), &paint); 715 return color_mask; 716 } 717 718 // static 719 SkBitmap SkBitmapOperations::CreateDropShadow( 720 const SkBitmap& bitmap, 721 const gfx::ShadowValues& shadows) { 722 DCHECK(bitmap.colorType() == kN32_SkColorType); 723 724 // Shadow margin insets are negative values because they grow outside. 725 // Negate them here as grow direction is not important and only pixel value 726 // is of interest here. 727 gfx::Insets shadow_margin = -gfx::ShadowValue::GetMargin(shadows); 728 729 SkBitmap image_with_shadow; 730 image_with_shadow.allocN32Pixels(bitmap.width() + shadow_margin.width(), 731 bitmap.height() + shadow_margin.height()); 732 image_with_shadow.eraseARGB(0, 0, 0, 0); 733 734 SkCanvas canvas(image_with_shadow); 735 canvas.translate(SkIntToScalar(shadow_margin.left()), 736 SkIntToScalar(shadow_margin.top())); 737 738 SkPaint paint; 739 for (size_t i = 0; i < shadows.size(); ++i) { 740 const gfx::ShadowValue& shadow = shadows[i]; 741 SkBitmap shadow_image = SkBitmapOperations::CreateColorMask(bitmap, 742 shadow.color()); 743 744 skia::RefPtr<SkBlurImageFilter> filter = 745 skia::AdoptRef(SkBlurImageFilter::Create( 746 SkDoubleToScalar(shadow.blur()), SkDoubleToScalar(shadow.blur()))); 747 paint.setImageFilter(filter.get()); 748 749 canvas.saveLayer(0, &paint); 750 canvas.drawBitmap(shadow_image, 751 SkIntToScalar(shadow.x()), 752 SkIntToScalar(shadow.y())); 753 canvas.restore(); 754 } 755 756 canvas.drawBitmap(bitmap, SkIntToScalar(0), SkIntToScalar(0)); 757 return image_with_shadow; 758 } 759 760 // static 761 SkBitmap SkBitmapOperations::Rotate(const SkBitmap& source, 762 RotationAmount rotation) { 763 SkBitmap result; 764 SkScalar angle = SkFloatToScalar(0.0f); 765 766 switch (rotation) { 767 case ROTATION_90_CW: 768 angle = SkFloatToScalar(90.0f); 769 result.allocN32Pixels(source.height(), source.width()); 770 break; 771 case ROTATION_180_CW: 772 angle = SkFloatToScalar(180.0f); 773 result.allocN32Pixels(source.width(), source.height()); 774 break; 775 case ROTATION_270_CW: 776 angle = SkFloatToScalar(270.0f); 777 result.allocN32Pixels(source.height(), source.width()); 778 break; 779 } 780 781 SkCanvas canvas(result); 782 canvas.clear(SkColorSetARGB(0, 0, 0, 0)); 783 784 canvas.translate(SkFloatToScalar(result.width() * 0.5f), 785 SkFloatToScalar(result.height() * 0.5f)); 786 canvas.rotate(angle); 787 canvas.translate(-SkFloatToScalar(source.width() * 0.5f), 788 -SkFloatToScalar(source.height() * 0.5f)); 789 canvas.drawBitmap(source, 0, 0); 790 canvas.flush(); 791 792 return result; 793 } 794
