1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/images/transform_scanline.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,140 @@
1.4 +
1.5 +/*
1.6 + * Copyright 2012 The Android Open Source Project
1.7 + *
1.8 + * Use of this source code is governed by a BSD-style license that can be
1.9 + * found in the LICENSE file.
1.10 + */
1.11 +
1.12 +/**
1.13 + * Functions to transform scanlines between packed-pixel formats.
1.14 + */
1.15 +
1.16 +#include "SkBitmap.h"
1.17 +#include "SkColor.h"
1.18 +#include "SkColorPriv.h"
1.19 +#include "SkPreConfig.h"
1.20 +#include "SkUnPreMultiply.h"
1.21 +
1.22 +/**
1.23 + * Function template for transforming scanlines.
1.24 + * Transform 'width' pixels from 'src' buffer into 'dst' buffer,
1.25 + * repacking color channel data as appropriate for the given transformation.
1.26 + */
1.27 +typedef void (*transform_scanline_proc)(const char* SK_RESTRICT src,
1.28 + int width, char* SK_RESTRICT dst);
1.29 +
1.30 +/**
1.31 + * Identity transformation: just copy bytes from src to dst.
1.32 + */
1.33 +static void transform_scanline_memcpy(const char* SK_RESTRICT src, int width,
1.34 + char* SK_RESTRICT dst) {
1.35 + memcpy(dst, src, width);
1.36 +}
1.37 +
1.38 +/**
1.39 + * Transform from kRGB_565_Config to 3-bytes-per-pixel RGB.
1.40 + * Alpha channel data is not present in kRGB_565_Config format, so there is no
1.41 + * alpha channel data to preserve.
1.42 + */
1.43 +static void transform_scanline_565(const char* SK_RESTRICT src, int width,
1.44 + char* SK_RESTRICT dst) {
1.45 + const uint16_t* SK_RESTRICT srcP = (const uint16_t*)src;
1.46 + for (int i = 0; i < width; i++) {
1.47 + unsigned c = *srcP++;
1.48 + *dst++ = SkPacked16ToR32(c);
1.49 + *dst++ = SkPacked16ToG32(c);
1.50 + *dst++ = SkPacked16ToB32(c);
1.51 + }
1.52 +}
1.53 +
1.54 +/**
1.55 + * Transform from kARGB_8888_Config to 3-bytes-per-pixel RGB.
1.56 + * Alpha channel data, if any, is abandoned.
1.57 + */
1.58 +static void transform_scanline_888(const char* SK_RESTRICT src, int width,
1.59 + char* SK_RESTRICT dst) {
1.60 + const SkPMColor* SK_RESTRICT srcP = (const SkPMColor*)src;
1.61 + for (int i = 0; i < width; i++) {
1.62 + SkPMColor c = *srcP++;
1.63 + *dst++ = SkGetPackedR32(c);
1.64 + *dst++ = SkGetPackedG32(c);
1.65 + *dst++ = SkGetPackedB32(c);
1.66 + }
1.67 +}
1.68 +
1.69 +/**
1.70 + * Transform from kARGB_4444_Config to 3-bytes-per-pixel RGB.
1.71 + * Alpha channel data, if any, is abandoned.
1.72 + */
1.73 +static void transform_scanline_444(const char* SK_RESTRICT src, int width,
1.74 + char* SK_RESTRICT dst) {
1.75 + const SkPMColor16* SK_RESTRICT srcP = (const SkPMColor16*)src;
1.76 + for (int i = 0; i < width; i++) {
1.77 + SkPMColor16 c = *srcP++;
1.78 + *dst++ = SkPacked4444ToR32(c);
1.79 + *dst++ = SkPacked4444ToG32(c);
1.80 + *dst++ = SkPacked4444ToB32(c);
1.81 + }
1.82 +}
1.83 +
1.84 +/**
1.85 + * Transform from kARGB_8888_Config to 4-bytes-per-pixel RGBA.
1.86 + * (This would be the identity transformation, except for byte-order and
1.87 + * scaling of RGB based on alpha channel).
1.88 + */
1.89 +static void transform_scanline_8888(const char* SK_RESTRICT src, int width,
1.90 + char* SK_RESTRICT dst) {
1.91 + const SkPMColor* SK_RESTRICT srcP = (const SkPMColor*)src;
1.92 + const SkUnPreMultiply::Scale* SK_RESTRICT table =
1.93 + SkUnPreMultiply::GetScaleTable();
1.94 +
1.95 + for (int i = 0; i < width; i++) {
1.96 + SkPMColor c = *srcP++;
1.97 + unsigned a = SkGetPackedA32(c);
1.98 + unsigned r = SkGetPackedR32(c);
1.99 + unsigned g = SkGetPackedG32(c);
1.100 + unsigned b = SkGetPackedB32(c);
1.101 +
1.102 + if (0 != a && 255 != a) {
1.103 + SkUnPreMultiply::Scale scale = table[a];
1.104 + r = SkUnPreMultiply::ApplyScale(scale, r);
1.105 + g = SkUnPreMultiply::ApplyScale(scale, g);
1.106 + b = SkUnPreMultiply::ApplyScale(scale, b);
1.107 + }
1.108 + *dst++ = r;
1.109 + *dst++ = g;
1.110 + *dst++ = b;
1.111 + *dst++ = a;
1.112 + }
1.113 +}
1.114 +
1.115 +/**
1.116 + * Transform from kARGB_8888_Config to 4-bytes-per-pixel RGBA,
1.117 + * with scaling of RGB based on alpha channel.
1.118 + */
1.119 +static void transform_scanline_4444(const char* SK_RESTRICT src, int width,
1.120 + char* SK_RESTRICT dst) {
1.121 + const SkPMColor16* SK_RESTRICT srcP = (const SkPMColor16*)src;
1.122 + const SkUnPreMultiply::Scale* SK_RESTRICT table =
1.123 + SkUnPreMultiply::GetScaleTable();
1.124 +
1.125 + for (int i = 0; i < width; i++) {
1.126 + SkPMColor16 c = *srcP++;
1.127 + unsigned a = SkPacked4444ToA32(c);
1.128 + unsigned r = SkPacked4444ToR32(c);
1.129 + unsigned g = SkPacked4444ToG32(c);
1.130 + unsigned b = SkPacked4444ToB32(c);
1.131 +
1.132 + if (0 != a && 255 != a) {
1.133 + SkUnPreMultiply::Scale scale = table[a];
1.134 + r = SkUnPreMultiply::ApplyScale(scale, r);
1.135 + g = SkUnPreMultiply::ApplyScale(scale, g);
1.136 + b = SkUnPreMultiply::ApplyScale(scale, b);
1.137 + }
1.138 + *dst++ = r;
1.139 + *dst++ = g;
1.140 + *dst++ = b;
1.141 + *dst++ = a;
1.142 + }
1.143 +}
