diff -r 000000000000 -r 6474c204b198 gfx/thebes/gfxColor.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gfx/thebes/gfxColor.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,227 @@ +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef GFX_COLOR_H +#define GFX_COLOR_H + +#include "gfxTypes.h" + +#include "mozilla/Attributes.h" // for MOZ_ALWAYS_INLINE +#include "mozilla/Endian.h" // for mozilla::NativeEndian::swapToBigEndian + +#define GFX_UINT32_FROM_BPTR(pbptr,i) (((uint32_t*)(pbptr))[i]) + +/** + * GFX_0XFF_PPIXEL_FROM_BPTR(x) + * + * Avoid tortured construction of 32-bit ARGB pixel from 3 individual bytes + * of memory plus constant 0xFF. RGB bytes are already contiguous! + * Equivalent to: GFX_PACKED_PIXEL(0xff,r,g,b) + * + * Attempt to use fast byte-swapping instruction(s), e.g. bswap on x86, in + * preference to a sequence of shift/or operations. + */ +#define GFX_0XFF_PPIXEL_FROM_UINT32(x) \ + ( (mozilla::NativeEndian::swapToBigEndian(uint32_t(x)) >> 8) | (0xFFU << 24) ) + +#define GFX_0XFF_PPIXEL_FROM_BPTR(x) \ + ( GFX_0XFF_PPIXEL_FROM_UINT32(GFX_UINT32_FROM_BPTR((x),0)) ) + +/** + * GFX_BLOCK_RGB_TO_FRGB(from,to) + * sizeof(*from) == sizeof(char) + * sizeof(*to) == sizeof(uint32_t) + * + * Copy 4 pixels at a time, reading blocks of 12 bytes (RGB x4) + * and writing blocks of 16 bytes (FRGB x4) + */ +#define GFX_BLOCK_RGB_TO_FRGB(from,to) \ + PR_BEGIN_MACRO \ + uint32_t m0 = GFX_UINT32_FROM_BPTR(from,0), \ + m1 = GFX_UINT32_FROM_BPTR(from,1), \ + m2 = GFX_UINT32_FROM_BPTR(from,2), \ + rgbr = mozilla::NativeEndian::swapToBigEndian(m0), \ + gbrg = mozilla::NativeEndian::swapToBigEndian(m1), \ + brgb = mozilla::NativeEndian::swapToBigEndian(m2), \ + p0, p1, p2, p3; \ + p0 = 0xFF000000 | ((rgbr) >> 8); \ + p1 = 0xFF000000 | ((rgbr) << 16) | ((gbrg) >> 16); \ + p2 = 0xFF000000 | ((gbrg) << 8) | ((brgb) >> 24); \ + p3 = 0xFF000000 | (brgb); \ + to[0] = p0; to[1] = p1; to[2] = p2; to[3] = p3; \ + PR_END_MACRO + +/** + * Fast approximate division by 255. It has the property that + * for all 0 <= n <= 255*255, GFX_DIVIDE_BY_255(n) == n/255. + * But it only uses two adds and two shifts instead of an + * integer division (which is expensive on many processors). + * + * equivalent to ((v)/255) + */ +#define GFX_DIVIDE_BY_255(v) \ + (((((unsigned)(v)) << 8) + ((unsigned)(v)) + 255) >> 16) + +/** + * Fast premultiply + * + * equivalent to (((c)*(a))/255) + */ +uint8_t MOZ_ALWAYS_INLINE gfxPreMultiply(uint8_t c, uint8_t a) { + return GFX_DIVIDE_BY_255((c)*(a)); +} + +/** + * Pack the 4 8-bit channels (A,R,G,B) + * into a 32-bit packed NON-premultiplied pixel. + */ +uint32_t MOZ_ALWAYS_INLINE +gfxPackedPixelNoPreMultiply(uint8_t a, uint8_t r, uint8_t g, uint8_t b) { + return (((a) << 24) | ((r) << 16) | ((g) << 8) | (b)); +} + +/** + * Pack the 4 8-bit channels (A,R,G,B) + * into a 32-bit packed premultiplied pixel. + */ +uint32_t MOZ_ALWAYS_INLINE +gfxPackedPixel(uint8_t a, uint8_t r, uint8_t g, uint8_t b) { + if (a == 0x00) + return 0x00000000; + else if (a == 0xFF) { + return gfxPackedPixelNoPreMultiply(a, r, g, b); + } else { + return ((a) << 24) | + (gfxPreMultiply(r,a) << 16) | + (gfxPreMultiply(g,a) << 8) | + (gfxPreMultiply(b,a)); + } +} + +/** + * A color value, storing red, green, blue and alpha components. + * This class does not use premultiplied alpha. + * + * XXX should this use doubles (instead of gfxFloat), for consistency with + * cairo? + */ +struct gfxRGBA { + gfxFloat r, g, b, a; + + enum PackedColorType { + PACKED_ABGR, + PACKED_ABGR_PREMULTIPLIED, + + PACKED_ARGB, + PACKED_ARGB_PREMULTIPLIED, + + PACKED_XRGB + }; + + gfxRGBA() { } + /** + * Intialize this color using explicit red, green, blue and alpha + * values. + */ + MOZ_CONSTEXPR gfxRGBA(gfxFloat _r, gfxFloat _g, gfxFloat _b, gfxFloat _a=1.0) : r(_r), g(_g), b(_b), a(_a) {} + + /** + * Initialize this color from a packed 32-bit color. + * The color value is interpreted based on colorType; + * all values use the native platform endianness. + * + * Resulting gfxRGBA stores non-premultiplied data. + * + * @see gfxRGBA::Packed + */ + gfxRGBA(uint32_t c, PackedColorType colorType = PACKED_ABGR) { + if (colorType == PACKED_ABGR || + colorType == PACKED_ABGR_PREMULTIPLIED) + { + r = ((c >> 0) & 0xff) * (1.0 / 255.0); + g = ((c >> 8) & 0xff) * (1.0 / 255.0); + b = ((c >> 16) & 0xff) * (1.0 / 255.0); + a = ((c >> 24) & 0xff) * (1.0 / 255.0); + } else if (colorType == PACKED_ARGB || + colorType == PACKED_XRGB || + colorType == PACKED_ARGB_PREMULTIPLIED) + { + b = ((c >> 0) & 0xff) * (1.0 / 255.0); + g = ((c >> 8) & 0xff) * (1.0 / 255.0); + r = ((c >> 16) & 0xff) * (1.0 / 255.0); + a = ((c >> 24) & 0xff) * (1.0 / 255.0); + } + + if (colorType == PACKED_ABGR_PREMULTIPLIED || + colorType == PACKED_ARGB_PREMULTIPLIED) + { + if (a > 0.0) { + r /= a; + g /= a; + b /= a; + } + } else if (colorType == PACKED_XRGB) { + a = 1.0; + } + } + + bool operator==(const gfxRGBA& other) const + { + return r == other.r && g == other.g && b == other.b && a == other.a; + } + bool operator!=(const gfxRGBA& other) const + { + return !(*this == other); + } + + /** + * Returns this color value as a packed 32-bit integer. This reconstructs + * the int32_t based on the given colorType, always in the native byte order. + * + * Note: gcc 4.2.3 on at least Ubuntu (x86) does something strange with + * (uint8_t)(c * 255.0) << x, where the result is different than + * double d = c * 255.0; v = ((uint8_t) d) << x. + */ + uint32_t Packed(PackedColorType colorType = PACKED_ABGR) const { + gfxFloat rb = (r * 255.0); + gfxFloat gb = (g * 255.0); + gfxFloat bb = (b * 255.0); + gfxFloat ab = (a * 255.0); + + if (colorType == PACKED_ABGR) { + return (uint8_t(ab) << 24) | + (uint8_t(bb) << 16) | + (uint8_t(gb) << 8) | + (uint8_t(rb) << 0); + } + if (colorType == PACKED_ARGB || colorType == PACKED_XRGB) { + return (uint8_t(ab) << 24) | + (uint8_t(rb) << 16) | + (uint8_t(gb) << 8) | + (uint8_t(bb) << 0); + } + + rb *= a; + gb *= a; + bb *= a; + + if (colorType == PACKED_ABGR_PREMULTIPLIED) { + return (((uint8_t)(ab) << 24) | + ((uint8_t)(bb) << 16) | + ((uint8_t)(gb) << 8) | + ((uint8_t)(rb) << 0)); + } + if (colorType == PACKED_ARGB_PREMULTIPLIED) { + return (((uint8_t)(ab) << 24) | + ((uint8_t)(rb) << 16) | + ((uint8_t)(gb) << 8) | + ((uint8_t)(bb) << 0)); + } + + return 0; + } +}; + +#endif /* _GFX_COLOR_H */