/* -*- 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 */ MOZ_IMPLICIT 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 */