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Diffstat (limited to 'mypaint/lib/composite_rgbx.hpp')
| -rw-r--r-- | mypaint/lib/composite_rgbx.hpp | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/mypaint/lib/composite_rgbx.hpp b/mypaint/lib/composite_rgbx.hpp new file mode 100644 index 0000000..d7bdc87 --- /dev/null +++ b/mypaint/lib/composite_rgbx.hpp @@ -0,0 +1,329 @@ +/* This file is part of MyPaint. + * Copyright (C) 2012 by Andrew Chadwick <a.t.chadwick@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + + +inline void +#ifdef COMPOSITE_MODE_RGBA +rgba_composite_src_over_rgba +#else +rgba_composite_src_over_rgbu +#endif + (const uint16_t src_p[], + uint16_t dst_p[], + const uint16_t opac) +{ + const uint16_t src_alpha = CLAMP((uint32_t)(opac*src_p[3])>>15, 0, 1<<15); + const uint32_t one_minus_src_alpha = (1<<15) - src_alpha; + + // Dca: destination component with premult alpha + // Da: destination alpha channel + // + // Dca' = Sca*Da + Sca*(1 - Da) + Dca*(1 - Sa) + // = Sca + Dca*(1 - Sa) + // + dst_p[0] = ((uint32_t)src_p[0]*opac + one_minus_src_alpha*dst_p[0]) >> 15; + dst_p[1] = ((uint32_t)src_p[1]*opac + one_minus_src_alpha*dst_p[1]) >> 15; + dst_p[2] = ((uint32_t)src_p[2]*opac + one_minus_src_alpha*dst_p[2]) >> 15; + +#ifdef COMPOSITE_MODE_RGBA + // Da' = Sa*Da + Sa*(1 - Da) + Da*(1 - Sa) + // = (Sa*Da + Sa - Sa*Da) + Da*(1 - Sa) + // = Sa + Da*(1 - Sa) + // + dst_p[3] = src_alpha + ((one_minus_src_alpha*dst_p[3]) >> 15); +#endif +} + + +inline void +#ifdef COMPOSITE_MODE_RGBA +rgba_composite_multiply_rgba +#else +rgba_composite_multiply_rgbu +#endif + (const uint16_t src_p[], + uint16_t dst_p[], + const uint16_t opac) +{ + // Dca' = Sca*Dca + Sca*(1 - Da) + Dca*(1 - Sa) + // + // If Da == 1, which is the case in RGBU mode, this becomes + // + // Dca' = Sca*Dca + 0 + Dca*(1 - Sa) + // = Dca * (Sca + (1 - Sa)) + // + const uint16_t src_alpha = CLAMP((uint32_t)(opac * src_p[3]) / (1<<15), + 0, 1<<15); + const uint32_t one_minus_src_alpha = (1<<15) - src_alpha; + const uint32_t src_col0 = ((uint32_t) src_p[0] * opac) >> 15; + const uint32_t src_col1 = ((uint32_t) src_p[1] * opac) >> 15; + const uint32_t src_col2 = ((uint32_t) src_p[2] * opac) >> 15; + dst_p[0] = ((uint32_t)src_col0*dst_p[0]+one_minus_src_alpha*dst_p[0])>>15; + dst_p[1] = ((uint32_t)src_col1*dst_p[1]+one_minus_src_alpha*dst_p[1])>>15; + dst_p[2] = ((uint32_t)src_col2*dst_p[2]+one_minus_src_alpha*dst_p[2])>>15; +#ifdef COMPOSITE_MODE_RGBA + // Sca*(1 - Da) != 0, add it in + const uint32_t one_minus_dst_alpha = (1<<15) - dst_p[3]; + dst_p[0] += (((uint32_t)src_col0 * one_minus_dst_alpha) >> 15); + dst_p[1] += (((uint32_t)src_col1 * one_minus_dst_alpha) >> 15); + dst_p[2] += (((uint32_t)src_col2 * one_minus_dst_alpha) >> 15); + + // Da' = Sa*Da + Sa*(1 - Da) + Da*(1 - Sa) + // = (Sa*Da + Sa - Sa*Da) + Da*(1 - Sa) + // = Sa + (1 - Sa)*Da + dst_p[3] = src_alpha + ((one_minus_src_alpha*dst_p[3]) >> 15); +#endif +} + + +inline void +#ifdef COMPOSITE_MODE_RGBA +rgba_composite_screen_rgba +#else +rgba_composite_screen_rgbu +#endif + (const uint16_t src_p[], + uint16_t dst_p[], + const uint16_t opac) +{ + // Dca' = (Sca*Da + Dca*Sa - Sca*Dca) + Sca*(1 - Da) + Dca*(1 - Sa) + // = Sca + Dca - Sca*Dca + const uint32_t col0 = ((uint32_t)src_p[0]*opac) + + (((uint32_t)dst_p[0]) << 15); + const uint32_t col1 = ((uint32_t)src_p[1]*opac) + + (((uint32_t)dst_p[1]) << 15); + const uint32_t col2 = ((uint32_t)src_p[2]*opac) + + (((uint32_t)dst_p[2]) << 15); + const uint32_t src_col0 = ((uint32_t)src_p[0] * opac) >> 15; + const uint32_t src_col1 = ((uint32_t)src_p[1] * opac) >> 15; + const uint32_t src_col2 = ((uint32_t)src_p[2] * opac) >> 15; + dst_p[0] = (col0 - ((uint32_t)src_col0*dst_p[0])) >> 15; + dst_p[1] = (col1 - ((uint32_t)src_col1*dst_p[1])) >> 15; + dst_p[2] = (col2 - ((uint32_t)src_col2*dst_p[2])) >> 15; +#ifdef COMPOSITE_MODE_RGBA + // Da' = Sa + Da - Sa*Da + const uint32_t src_alpha = ((uint32_t)src_p[3] * opac) >> 15; + dst_p[3] = src_alpha + (uint32_t)dst_p[3] + - ((src_alpha * (uint32_t)dst_p[3]) >> 15); +#endif +} + + +inline void +#ifdef COMPOSITE_MODE_RGBA +rgba_composite_color_dodge_rgba +#else +rgba_composite_color_dodge_rgbu +#endif + (const uint16_t src_p[], + uint16_t dst_p[], + const uint16_t opac) +{ + const uint32_t src_alpha = ((uint32_t)src_p[3]*opac)>>15; + const uint32_t one_minus_src_alpha = (1<<15) - src_alpha; +#ifdef COMPOSITE_MODE_RGBA + const uint32_t dst_alpha = dst_p[3]; + const uint32_t one_minus_dst_alpha = (1<<15) - dst_alpha; +#endif + + for (int c=0; c<3; c++) { + const uint32_t s = ((uint32_t)src_p[c]*opac)>>15; + const uint32_t d = dst_p[c]; + const uint32_t src_alpha_minus_src = src_alpha - s; + if (src_alpha_minus_src == 0 && d == 0) { + // Sca == Sa and Dca == 0 + // Dca' = Sca*(1 - Da) + Dca*(1 - Sa) + // = Sca*(1 - Da) +#ifdef COMPOSITE_MODE_RGBA + dst_p[c] = CLAMP((s * one_minus_dst_alpha) >> 15, 0, (1<<15)); +#else + dst_p[c] = 0; +#endif + } + else if (src_alpha_minus_src == 0) { + // otherwise if Sca == Sa + // Dca' = Sa*Da + Sca*(1 - Da) + Dca*(1 - Sa) + // = Sca*Da + Sca*(1 - Da) + Dca*(1 - Sa) + // = Sca*(Da + 1 - Da) + Dca*(1 - Sa) + // = Sca + Dca*(1 - Sa) + dst_p[c] = CLAMP( s + ((d * one_minus_src_alpha)>>15), + 0, (1<<15) ); + } + else { + // Sca < Sa + // Dca' = Sa*Da * min(1, Dca/Da * Sa/(Sa - Sca)) + // + Sca*(1 - Da) + Dca*(1 - Sa) + const uint32_t dst_times_src_alpha_B30 = d*src_alpha; + // when 1 < Dca/Da * Sa/(Sa - Sca) + // 1 < (Dca*Sa) / (Da*(Sa - Sca) + // (Da*(Sa - Sca) < (Dca*Sa) because Sca - Sa is -ve and nonzero +#ifdef COMPOSITE_MODE_RGBA + if (dst_times_src_alpha_B30 > (dst_alpha * src_alpha_minus_src)) +#else + if (dst_times_src_alpha_B30 > (src_alpha_minus_src << 15)) +#endif + { + // min(...)==1 + // Dca' = Sa * Da * min(...) + Sca*(1 - Da) + Dca*(1 - Sa) + // Dca' = Sa * Da + Sca*(1 - Da) + Dca*(1 - Sa) + dst_p[c] = CLAMP( + ( (d * one_minus_src_alpha) // B30 +#ifdef COMPOSITE_MODE_RGBA + + (s * one_minus_dst_alpha) // B30 + + (src_alpha * dst_alpha) // B30 +#else + // + (s * 0) + + (src_alpha << 15) // B30 +#endif + ) >> 15, + 0, 1<<15); + } + else { + // min(...) == Dca/Da * Sa/(Sa - Sca) + // Dca' = Sa * Da * min(...) + Sca*(1 - Da) + Dca*(1 - Sa) + // Dca' = Sa * Da * Dca/Da * Sa/(Sa - Sca) + // + Sca*(1 - Da) + Dca*(1 - Sa) + // Dca' = Sa * Dca * Sa/(Sa - Sca) + // + Sca*(1 - Da) + Dca*(1 - Sa) + dst_p[c] = CLAMP( + ( src_alpha * (dst_times_src_alpha_B30>>15) + / src_alpha_minus_src ) +#ifdef COMPOSITE_MODE_RGBA + + ((s * one_minus_dst_alpha) >> 15) +#endif + + ((d * one_minus_src_alpha) >> 15), + 0, 1<<15); + } + } +#ifdef HEAVY_DEBUG + assert(dst_p[c] <= (1<<15)); + assert(src_p[c] <= (1<<15)); +#endif + } + +#ifdef COMPOSITE_MODE_RGBA + // Da' = Sa + Da - Sa*Da + dst_p[3] = CLAMP(src_alpha + dst_alpha - ((src_alpha*dst_alpha)>>15), + 0, (1<<15)); +#ifdef HEAVY_DEBUG + assert(src_p[0] <= src_p[3]); + assert(dst_p[0] <= dst_p[3]); + assert(src_p[1] <= src_p[3]); + assert(dst_p[1] <= dst_p[3]); + assert(src_p[2] <= src_p[3]); + assert(dst_p[2] <= dst_p[3]); +#endif //HEAVY_DEBUG +#endif //COMPOSITE_MODE_RGBA + +#ifdef HEAVY_DEBUG + assert(dst_p[3] <= (1<<15)); + assert(src_p[3] <= (1<<15)); +#endif +} + + + +inline void +#ifdef COMPOSITE_MODE_RGBA +rgba_composite_color_burn_rgba +#else +rgba_composite_color_burn_rgbu +#endif + (const uint16_t src_p[], + uint16_t dst_p[], + const uint16_t opac) +{ + const uint32_t src_alpha30 = (uint32_t)src_p[3]*opac; + const uint32_t src_alpha = src_alpha30>>15; + const uint32_t one_minus_src_alpha = (1<<15) - src_alpha; +#ifdef COMPOSITE_MODE_RGBA + const uint32_t dst_alpha = dst_p[3]; + const uint32_t one_minus_dst_alpha = (1<<15) - dst_alpha; +#else + const uint32_t dst_alpha = 1<<15; +#endif + for (int c=0; c<3; c++) { + const uint32_t s30 = (uint32_t)src_p[c] * opac; + const uint32_t s = s30 >> 15; + const uint32_t d = dst_p[c]; + if (s == 0) { + if (d != dst_alpha) { + //if Sca == 0 and Dca == Da + // Dca' = Sa*Da + Sca*(1 - Da) + Dca*(1 - Sa) + // = Sa*Dca + Dca*(1 - Sa) + // = Sa*Dca + Dca - Sa*Dca + // = Dca + + //otherwise if Sca == 0 + // Dca' = Sca*(1 - Da) + Dca*(1 - Sa) + // = Dca*(1 - Sa) + dst_p[c] = CLAMP(((d * one_minus_src_alpha) >> 15), + 0, (1<<15)); + } + } + else { +#ifdef HEAVY_DEBUG + assert(s <= (1<<15)); + assert(s > 0); +#endif + //otherwise if Sca > 0 + // let i = Sca*(1 - Da) + Dca*(1 - Sa) + // let m = (1 - Dca/Da) * Sa/Sca + // + // Dca' = Sa*Da - Sa*Da * min(1, (1 - Dca/Da) * Sa/Sca) + i + // = Sa*Da * (1 - min(1, (1 - Dca/Da) * Sa/Sca)) + i + +#ifdef COMPOSITE_MODE_RGBA + uint32_t res = (s*one_minus_dst_alpha + d*one_minus_src_alpha)>>15; + if (dst_alpha > 0) { + const uint32_t m = ( ((1<<15) - ((d << 15) / dst_alpha)) + * src_alpha) / s; + if (m < (1<<15)) { + res += ( ((src_alpha * dst_alpha) >> 15) + * ((1<<15) - m) ) >> 15; + } + } +#else + uint32_t res = (d*one_minus_src_alpha)>>15; + const uint32_t m = (((1<<15) - d) + * src_alpha) / s; + if (m < (1<<15)) { + res += ( src_alpha + * ((1<<15) - m) ) >> 15; + } +#endif + dst_p[c] = CLAMP(res, 0, (1<<15)); + } +#ifdef HEAVY_DEBUG + assert(dst_p[c] <= (1<<15)); + assert(src_p[c] <= (1<<15)); +#endif + } + +#ifdef COMPOSITE_MODE_RGBA + // Da' = Sa + Da - Sa*Da + dst_p[3] = CLAMP(src_alpha + dst_alpha - ((src_alpha*dst_alpha)>>15), + 0, (1<<15)); +#ifdef HEAVY_DEBUG + assert(src_p[0] <= src_p[3]); + assert(dst_p[0] <= dst_p[3]); + assert(src_p[1] <= src_p[3]); + assert(dst_p[1] <= dst_p[3]); + assert(src_p[2] <= src_p[3]); + assert(dst_p[2] <= dst_p[3]); +#endif //HEAVY_DEBUG +#endif //COMPOSITE_MODE_RGBA + +#ifdef HEAVY_DEBUG + assert(dst_p[3] <= (1<<15)); + assert(src_p[3] <= (1<<15)); +#endif +} + + |