agg/include/agg_color_rgba.h

1354 lines
44 KiB
C++

//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
//
// Adaptation for high precision colors has been sponsored by
// Liberty Technology Systems, Inc., visit http://lib-sys.com
//
// Liberty Technology Systems, Inc. is the provider of
// PostScript and PDF technology for software developers.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
#ifndef AGG_COLOR_RGBA_INCLUDED
#define AGG_COLOR_RGBA_INCLUDED
#include <cmath>
#include "agg_basics.h"
#include "agg_gamma_lut.h"
namespace agg
{
// Supported component orders for RGB and RGBA pixel formats
//=======================================================================
struct order_rgb { enum rgb_e { R=0, G=1, B=2, N=3 }; };
struct order_bgr { enum bgr_e { B=0, G=1, R=2, N=3 }; };
struct order_rgba { enum rgba_e { R=0, G=1, B=2, A=3, N=4 }; };
struct order_argb { enum argb_e { A=0, R=1, G=2, B=3, N=4 }; };
struct order_abgr { enum abgr_e { A=0, B=1, G=2, R=3, N=4 }; };
struct order_bgra { enum bgra_e { B=0, G=1, R=2, A=3, N=4 }; };
// Colorspace tag types.
struct linear {};
struct sRGB {};
//====================================================================rgba
struct rgba
{
typedef double value_type;
double r;
double g;
double b;
double a;
//--------------------------------------------------------------------
rgba() {}
//--------------------------------------------------------------------
rgba(double r_, double g_, double b_, double a_=1.0) :
r(r_), g(g_), b(b_), a(a_) {}
//--------------------------------------------------------------------
rgba(const rgba& c, double a_) : r(c.r), g(c.g), b(c.b), a(a_) {}
//--------------------------------------------------------------------
rgba& clear()
{
r = g = b = a = 0;
return *this;
}
//--------------------------------------------------------------------
rgba& transparent()
{
a = 0;
return *this;
}
//--------------------------------------------------------------------
rgba& opacity(double a_)
{
if (a_ < 0) a = 0;
else if (a_ > 1) a = 1;
else a = a_;
return *this;
}
//--------------------------------------------------------------------
double opacity() const
{
return a;
}
//--------------------------------------------------------------------
rgba& premultiply()
{
r *= a;
g *= a;
b *= a;
return *this;
}
//--------------------------------------------------------------------
rgba& premultiply(double a_)
{
if (a <= 0 || a_ <= 0)
{
r = g = b = a = 0;
}
else
{
a_ /= a;
r *= a_;
g *= a_;
b *= a_;
a = a_;
}
return *this;
}
//--------------------------------------------------------------------
rgba& demultiply()
{
if (a == 0)
{
r = g = b = 0;
}
else
{
double a_ = 1.0 / a;
r *= a_;
g *= a_;
b *= a_;
}
return *this;
}
//--------------------------------------------------------------------
rgba gradient(rgba c, double k) const
{
rgba ret;
ret.r = r + (c.r - r) * k;
ret.g = g + (c.g - g) * k;
ret.b = b + (c.b - b) * k;
ret.a = a + (c.a - a) * k;
return ret;
}
rgba& operator+=(const rgba& c)
{
r += c.r;
g += c.g;
b += c.b;
a += c.a;
return *this;
}
rgba& operator*=(double k)
{
r *= k;
g *= k;
b *= k;
a *= k;
return *this;
}
//--------------------------------------------------------------------
static rgba no_color() { return rgba(0,0,0,0); }
//--------------------------------------------------------------------
static rgba from_wavelength(double wl, double gamma = 1.0);
//--------------------------------------------------------------------
explicit rgba(double wavelen, double gamma=1.0)
{
*this = from_wavelength(wavelen, gamma);
}
};
inline rgba operator+(const rgba& a, const rgba& b)
{
return rgba(a) += b;
}
inline rgba operator*(const rgba& a, double b)
{
return rgba(a) *= b;
}
//------------------------------------------------------------------------
inline rgba rgba::from_wavelength(double wl, double gamma)
{
rgba t(0.0, 0.0, 0.0);
if (wl >= 380.0 && wl <= 440.0)
{
t.r = -1.0 * (wl - 440.0) / (440.0 - 380.0);
t.b = 1.0;
}
else if (wl >= 440.0 && wl <= 490.0)
{
t.g = (wl - 440.0) / (490.0 - 440.0);
t.b = 1.0;
}
else if (wl >= 490.0 && wl <= 510.0)
{
t.g = 1.0;
t.b = -1.0 * (wl - 510.0) / (510.0 - 490.0);
}
else if (wl >= 510.0 && wl <= 580.0)
{
t.r = (wl - 510.0) / (580.0 - 510.0);
t.g = 1.0;
}
else if (wl >= 580.0 && wl <= 645.0)
{
t.r = 1.0;
t.g = -1.0 * (wl - 645.0) / (645.0 - 580.0);
}
else if (wl >= 645.0 && wl <= 780.0)
{
t.r = 1.0;
}
double s = 1.0;
if (wl > 700.0) s = 0.3 + 0.7 * (780.0 - wl) / (780.0 - 700.0);
else if (wl < 420.0) s = 0.3 + 0.7 * (wl - 380.0) / (420.0 - 380.0);
t.r = std::pow(t.r * s, gamma);
t.g = std::pow(t.g * s, gamma);
t.b = std::pow(t.b * s, gamma);
return t;
}
inline rgba rgba_pre(double r, double g, double b, double a)
{
return rgba(r, g, b, a).premultiply();
}
//===================================================================rgba8
template<class Colorspace>
struct rgba8T
{
typedef int8u value_type;
typedef int32u calc_type;
typedef int32 long_type;
enum base_scale_e
{
base_shift = 8,
base_scale = 1 << base_shift,
base_mask = base_scale - 1,
base_MSB = 1 << (base_shift - 1)
};
typedef rgba8T self_type;
value_type r;
value_type g;
value_type b;
value_type a;
static void convert(rgba8T<linear>& dst, const rgba8T<sRGB>& src)
{
dst.r = sRGB_conv<value_type>::rgb_from_sRGB(src.r);
dst.g = sRGB_conv<value_type>::rgb_from_sRGB(src.g);
dst.b = sRGB_conv<value_type>::rgb_from_sRGB(src.b);
dst.a = src.a;
}
static void convert(rgba8T<sRGB>& dst, const rgba8T<linear>& src)
{
dst.r = sRGB_conv<value_type>::rgb_to_sRGB(src.r);
dst.g = sRGB_conv<value_type>::rgb_to_sRGB(src.g);
dst.b = sRGB_conv<value_type>::rgb_to_sRGB(src.b);
dst.a = src.a;
}
static void convert(rgba8T<linear>& dst, const rgba& src)
{
dst.r = value_type(uround(src.r * base_mask));
dst.g = value_type(uround(src.g * base_mask));
dst.b = value_type(uround(src.b * base_mask));
dst.a = value_type(uround(src.a * base_mask));
}
static void convert(rgba8T<sRGB>& dst, const rgba& src)
{
// Use the "float" table.
dst.r = sRGB_conv<float>::rgb_to_sRGB(float(src.r));
dst.g = sRGB_conv<float>::rgb_to_sRGB(float(src.g));
dst.b = sRGB_conv<float>::rgb_to_sRGB(float(src.b));
dst.a = sRGB_conv<float>::alpha_to_sRGB(float(src.a));
}
static void convert(rgba& dst, const rgba8T<linear>& src)
{
dst.r = src.r / 255.0;
dst.g = src.g / 255.0;
dst.b = src.b / 255.0;
dst.a = src.a / 255.0;
}
static void convert(rgba& dst, const rgba8T<sRGB>& src)
{
// Use the "float" table.
dst.r = sRGB_conv<float>::rgb_from_sRGB(src.r);
dst.g = sRGB_conv<float>::rgb_from_sRGB(src.g);
dst.b = sRGB_conv<float>::rgb_from_sRGB(src.b);
dst.a = sRGB_conv<float>::alpha_from_sRGB(src.a);
}
//--------------------------------------------------------------------
rgba8T() {}
//--------------------------------------------------------------------
rgba8T(unsigned r_, unsigned g_, unsigned b_, unsigned a_ = base_mask) :
r(value_type(r_)),
g(value_type(g_)),
b(value_type(b_)),
a(value_type(a_)) {}
//--------------------------------------------------------------------
rgba8T(const rgba& c)
{
convert(*this, c);
}
//--------------------------------------------------------------------
rgba8T(const self_type& c, unsigned a_) :
r(c.r), g(c.g), b(c.b), a(value_type(a_)) {}
//--------------------------------------------------------------------
template<class T>
rgba8T(const rgba8T<T>& c)
{
convert(*this, c);
}
//--------------------------------------------------------------------
operator rgba() const
{
rgba c;
convert(c, *this);
return c;
}
//--------------------------------------------------------------------
static AGG_INLINE double to_double(value_type a)
{
return double(a) / base_mask;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type from_double(double a)
{
return value_type(uround(a * base_mask));
}
//--------------------------------------------------------------------
static AGG_INLINE value_type empty_value()
{
return 0;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type full_value()
{
return base_mask;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_transparent() const
{
return a == 0;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_opaque() const
{
return a == base_mask;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type invert(value_type x)
{
return base_mask - x;
}
//--------------------------------------------------------------------
// Fixed-point multiply, exact over int8u.
static AGG_INLINE value_type multiply(value_type a, value_type b)
{
calc_type t = a * b + base_MSB;
return value_type(((t >> base_shift) + t) >> base_shift);
}
//--------------------------------------------------------------------
static AGG_INLINE value_type demultiply(value_type a, value_type b)
{
if (a * b == 0)
{
return 0;
}
else if (a >= b)
{
return base_mask;
}
else return value_type((a * base_mask + (b >> 1)) / b);
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downscale(T a)
{
return a >> base_shift;
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downshift(T a, unsigned n)
{
return a >> n;
}
//--------------------------------------------------------------------
// Fixed-point multiply, exact over int8u.
// Specifically for multiplying a color component by a cover.
static AGG_INLINE value_type mult_cover(value_type a, cover_type b)
{
return multiply(a, b);
}
//--------------------------------------------------------------------
static AGG_INLINE cover_type scale_cover(cover_type a, value_type b)
{
return multiply(b, a);
}
//--------------------------------------------------------------------
// Interpolate p to q by a, assuming q is premultiplied by a.
static AGG_INLINE value_type prelerp(value_type p, value_type q, value_type a)
{
return p + q - multiply(p, a);
}
//--------------------------------------------------------------------
// Interpolate p to q by a.
static AGG_INLINE value_type lerp(value_type p, value_type q, value_type a)
{
int t = (q - p) * a + base_MSB - (p > q);
return value_type(p + (((t >> base_shift) + t) >> base_shift));
}
//--------------------------------------------------------------------
self_type& clear()
{
r = g = b = a = 0;
return *this;
}
//--------------------------------------------------------------------
self_type& transparent()
{
a = 0;
return *this;
}
//--------------------------------------------------------------------
self_type& opacity(double a_)
{
if (a_ < 0) a = 0;
else if (a_ > 1) a = 1;
else a = (value_type)uround(a_ * double(base_mask));
return *this;
}
//--------------------------------------------------------------------
double opacity() const
{
return double(a) / double(base_mask);
}
//--------------------------------------------------------------------
AGG_INLINE self_type& premultiply()
{
if (a != base_mask)
{
if (a == 0)
{
r = g = b = 0;
}
else
{
r = multiply(r, a);
g = multiply(g, a);
b = multiply(b, a);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& premultiply(unsigned a_)
{
if (a != base_mask || a_ < base_mask)
{
if (a == 0 || a_ == 0)
{
r = g = b = a = 0;
}
else
{
calc_type r_ = (calc_type(r) * a_) / a;
calc_type g_ = (calc_type(g) * a_) / a;
calc_type b_ = (calc_type(b) * a_) / a;
r = value_type((r_ > a_) ? a_ : r_);
g = value_type((g_ > a_) ? a_ : g_);
b = value_type((b_ > a_) ? a_ : b_);
a = value_type(a_);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& demultiply()
{
if (a < base_mask)
{
if (a == 0)
{
r = g = b = 0;
}
else
{
calc_type r_ = (calc_type(r) * base_mask) / a;
calc_type g_ = (calc_type(g) * base_mask) / a;
calc_type b_ = (calc_type(b) * base_mask) / a;
r = value_type((r_ > calc_type(base_mask)) ? calc_type(base_mask) : r_);
g = value_type((g_ > calc_type(base_mask)) ? calc_type(base_mask) : g_);
b = value_type((b_ > calc_type(base_mask)) ? calc_type(base_mask) : b_);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type gradient(const self_type& c, double k) const
{
self_type ret;
calc_type ik = uround(k * base_mask);
ret.r = lerp(r, c.r, ik);
ret.g = lerp(g, c.g, ik);
ret.b = lerp(b, c.b, ik);
ret.a = lerp(a, c.a, ik);
return ret;
}
//--------------------------------------------------------------------
AGG_INLINE void add(const self_type& c, unsigned cover)
{
calc_type cr, cg, cb, ca;
if (cover == cover_mask)
{
if (c.a == base_mask)
{
*this = c;
return;
}
else
{
cr = r + c.r;
cg = g + c.g;
cb = b + c.b;
ca = a + c.a;
}
}
else
{
cr = r + mult_cover(c.r, cover);
cg = g + mult_cover(c.g, cover);
cb = b + mult_cover(c.b, cover);
ca = a + mult_cover(c.a, cover);
}
r = (value_type)((cr > calc_type(base_mask)) ? calc_type(base_mask) : cr);
g = (value_type)((cg > calc_type(base_mask)) ? calc_type(base_mask) : cg);
b = (value_type)((cb > calc_type(base_mask)) ? calc_type(base_mask) : cb);
a = (value_type)((ca > calc_type(base_mask)) ? calc_type(base_mask) : ca);
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_dir(const GammaLUT& gamma)
{
r = gamma.dir(r);
g = gamma.dir(g);
b = gamma.dir(b);
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_inv(const GammaLUT& gamma)
{
r = gamma.inv(r);
g = gamma.inv(g);
b = gamma.inv(b);
}
//--------------------------------------------------------------------
static self_type no_color() { return self_type(0,0,0,0); }
//--------------------------------------------------------------------
static self_type from_wavelength(double wl, double gamma = 1.0)
{
return self_type(rgba::from_wavelength(wl, gamma));
}
};
typedef rgba8T<linear> rgba8;
typedef rgba8T<sRGB> srgba8;
//-------------------------------------------------------------rgb8_packed
inline rgba8 rgb8_packed(unsigned v)
{
return rgba8((v >> 16) & 0xFF, (v >> 8) & 0xFF, v & 0xFF);
}
//-------------------------------------------------------------bgr8_packed
inline rgba8 bgr8_packed(unsigned v)
{
return rgba8(v & 0xFF, (v >> 8) & 0xFF, (v >> 16) & 0xFF);
}
//------------------------------------------------------------argb8_packed
inline rgba8 argb8_packed(unsigned v)
{
return rgba8((v >> 16) & 0xFF, (v >> 8) & 0xFF, v & 0xFF, v >> 24);
}
//---------------------------------------------------------rgba8_gamma_dir
template<class GammaLUT>
rgba8 rgba8_gamma_dir(rgba8 c, const GammaLUT& gamma)
{
return rgba8(gamma.dir(c.r), gamma.dir(c.g), gamma.dir(c.b), c.a);
}
//---------------------------------------------------------rgba8_gamma_inv
template<class GammaLUT>
rgba8 rgba8_gamma_inv(rgba8 c, const GammaLUT& gamma)
{
return rgba8(gamma.inv(c.r), gamma.inv(c.g), gamma.inv(c.b), c.a);
}
//==================================================================rgba16
struct rgba16
{
typedef int16u value_type;
typedef int32u calc_type;
typedef int64 long_type;
enum base_scale_e
{
base_shift = 16,
base_scale = 1 << base_shift,
base_mask = base_scale - 1,
base_MSB = 1 << (base_shift - 1)
};
typedef rgba16 self_type;
value_type r;
value_type g;
value_type b;
value_type a;
//--------------------------------------------------------------------
rgba16() {}
//--------------------------------------------------------------------
rgba16(unsigned r_, unsigned g_, unsigned b_, unsigned a_=base_mask) :
r(value_type(r_)),
g(value_type(g_)),
b(value_type(b_)),
a(value_type(a_)) {}
//--------------------------------------------------------------------
rgba16(const self_type& c, unsigned a_) :
r(c.r), g(c.g), b(c.b), a(value_type(a_)) {}
//--------------------------------------------------------------------
rgba16(const rgba& c) :
r((value_type)uround(c.r * double(base_mask))),
g((value_type)uround(c.g * double(base_mask))),
b((value_type)uround(c.b * double(base_mask))),
a((value_type)uround(c.a * double(base_mask))) {}
//--------------------------------------------------------------------
rgba16(const rgba8& c) :
r(value_type((value_type(c.r) << 8) | c.r)),
g(value_type((value_type(c.g) << 8) | c.g)),
b(value_type((value_type(c.b) << 8) | c.b)),
a(value_type((value_type(c.a) << 8) | c.a)) {}
//--------------------------------------------------------------------
rgba16(const srgba8& c) :
r(sRGB_conv<value_type>::rgb_from_sRGB(c.r)),
g(sRGB_conv<value_type>::rgb_from_sRGB(c.g)),
b(sRGB_conv<value_type>::rgb_from_sRGB(c.b)),
a(sRGB_conv<value_type>::alpha_from_sRGB(c.a)) {}
//--------------------------------------------------------------------
operator rgba() const
{
return rgba(
r / 65535.0,
g / 65535.0,
b / 65535.0,
a / 65535.0);
}
//--------------------------------------------------------------------
operator rgba8() const
{
return rgba8(r >> 8, g >> 8, b >> 8, a >> 8);
}
//--------------------------------------------------------------------
operator srgba8() const
{
// Return (non-premultiplied) sRGB values.
return srgba8(
sRGB_conv<value_type>::rgb_to_sRGB(r),
sRGB_conv<value_type>::rgb_to_sRGB(g),
sRGB_conv<value_type>::rgb_to_sRGB(b),
sRGB_conv<value_type>::alpha_to_sRGB(a));
}
//--------------------------------------------------------------------
static AGG_INLINE double to_double(value_type a)
{
return double(a) / base_mask;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type from_double(double a)
{
return value_type(uround(a * base_mask));
}
//--------------------------------------------------------------------
static AGG_INLINE value_type empty_value()
{
return 0;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type full_value()
{
return base_mask;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_transparent() const
{
return a == 0;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_opaque() const
{
return a == base_mask;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type invert(value_type x)
{
return base_mask - x;
}
//--------------------------------------------------------------------
// Fixed-point multiply, exact over int16u.
static AGG_INLINE value_type multiply(value_type a, value_type b)
{
calc_type t = a * b + base_MSB;
return value_type(((t >> base_shift) + t) >> base_shift);
}
//--------------------------------------------------------------------
static AGG_INLINE value_type demultiply(value_type a, value_type b)
{
if (a * b == 0)
{
return 0;
}
else if (a >= b)
{
return base_mask;
}
else return value_type((a * base_mask + (b >> 1)) / b);
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downscale(T a)
{
return a >> base_shift;
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downshift(T a, unsigned n)
{
return a >> n;
}
//--------------------------------------------------------------------
// Fixed-point multiply, almost exact over int16u.
// Specifically for multiplying a color component by a cover.
static AGG_INLINE value_type mult_cover(value_type a, cover_type b)
{
return multiply(a, (b << 8) | b);
}
//--------------------------------------------------------------------
static AGG_INLINE cover_type scale_cover(cover_type a, value_type b)
{
return multiply((a << 8) | a, b) >> 8;
}
//--------------------------------------------------------------------
// Interpolate p to q by a, assuming q is premultiplied by a.
static AGG_INLINE value_type prelerp(value_type p, value_type q, value_type a)
{
return p + q - multiply(p, a);
}
//--------------------------------------------------------------------
// Interpolate p to q by a.
static AGG_INLINE value_type lerp(value_type p, value_type q, value_type a)
{
int t = (q - p) * a + base_MSB - (p > q);
return value_type(p + (((t >> base_shift) + t) >> base_shift));
}
//--------------------------------------------------------------------
self_type& clear()
{
r = g = b = a = 0;
return *this;
}
//--------------------------------------------------------------------
self_type& transparent()
{
a = 0;
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& opacity(double a_)
{
if (a_ < 0) a = 0;
if (a_ > 1) a = 1;
a = value_type(uround(a_ * double(base_mask)));
return *this;
}
//--------------------------------------------------------------------
double opacity() const
{
return double(a) / double(base_mask);
}
//--------------------------------------------------------------------
AGG_INLINE self_type& premultiply()
{
if (a != base_mask)
{
if (a == 0)
{
r = g = b = 0;
}
else
{
r = multiply(r, a);
g = multiply(g, a);
b = multiply(b, a);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& premultiply(unsigned a_)
{
if (a < base_mask || a_ < base_mask)
{
if (a == 0 || a_ == 0)
{
r = g = b = a = 0;
}
else
{
calc_type r_ = (calc_type(r) * a_) / a;
calc_type g_ = (calc_type(g) * a_) / a;
calc_type b_ = (calc_type(b) * a_) / a;
r = value_type((r_ > a_) ? a_ : r_);
g = value_type((g_ > a_) ? a_ : g_);
b = value_type((b_ > a_) ? a_ : b_);
a = value_type(a_);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& demultiply()
{
if (a < base_mask)
{
if (a == 0)
{
r = g = b = 0;
}
else
{
calc_type r_ = (calc_type(r) * base_mask) / a;
calc_type g_ = (calc_type(g) * base_mask) / a;
calc_type b_ = (calc_type(b) * base_mask) / a;
r = value_type((r_ > calc_type(base_mask)) ? calc_type(base_mask) : r_);
g = value_type((g_ > calc_type(base_mask)) ? calc_type(base_mask) : g_);
b = value_type((b_ > calc_type(base_mask)) ? calc_type(base_mask) : b_);
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type gradient(const self_type& c, double k) const
{
self_type ret;
calc_type ik = uround(k * base_mask);
ret.r = lerp(r, c.r, ik);
ret.g = lerp(g, c.g, ik);
ret.b = lerp(b, c.b, ik);
ret.a = lerp(a, c.a, ik);
return ret;
}
//--------------------------------------------------------------------
AGG_INLINE void add(const self_type& c, unsigned cover)
{
calc_type cr, cg, cb, ca;
if (cover == cover_mask)
{
if (c.a == base_mask)
{
*this = c;
return;
}
else
{
cr = r + c.r;
cg = g + c.g;
cb = b + c.b;
ca = a + c.a;
}
}
else
{
cr = r + mult_cover(c.r, cover);
cg = g + mult_cover(c.g, cover);
cb = b + mult_cover(c.b, cover);
ca = a + mult_cover(c.a, cover);
}
r = (value_type)((cr > calc_type(base_mask)) ? calc_type(base_mask) : cr);
g = (value_type)((cg > calc_type(base_mask)) ? calc_type(base_mask) : cg);
b = (value_type)((cb > calc_type(base_mask)) ? calc_type(base_mask) : cb);
a = (value_type)((ca > calc_type(base_mask)) ? calc_type(base_mask) : ca);
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_dir(const GammaLUT& gamma)
{
r = gamma.dir(r);
g = gamma.dir(g);
b = gamma.dir(b);
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_inv(const GammaLUT& gamma)
{
r = gamma.inv(r);
g = gamma.inv(g);
b = gamma.inv(b);
}
//--------------------------------------------------------------------
static self_type no_color() { return self_type(0,0,0,0); }
//--------------------------------------------------------------------
static self_type from_wavelength(double wl, double gamma = 1.0)
{
return self_type(rgba::from_wavelength(wl, gamma));
}
};
//------------------------------------------------------rgba16_gamma_dir
template<class GammaLUT>
rgba16 rgba16_gamma_dir(rgba16 c, const GammaLUT& gamma)
{
return rgba16(gamma.dir(c.r), gamma.dir(c.g), gamma.dir(c.b), c.a);
}
//------------------------------------------------------rgba16_gamma_inv
template<class GammaLUT>
rgba16 rgba16_gamma_inv(rgba16 c, const GammaLUT& gamma)
{
return rgba16(gamma.inv(c.r), gamma.inv(c.g), gamma.inv(c.b), c.a);
}
//====================================================================rgba32
struct rgba32
{
typedef float value_type;
typedef double calc_type;
typedef double long_type;
typedef rgba32 self_type;
value_type r;
value_type g;
value_type b;
value_type a;
//--------------------------------------------------------------------
rgba32() {}
//--------------------------------------------------------------------
rgba32(value_type r_, value_type g_, value_type b_, value_type a_= 1) :
r(r_), g(g_), b(b_), a(a_) {}
//--------------------------------------------------------------------
rgba32(const self_type& c, float a_) :
r(c.r), g(c.g), b(c.b), a(a_) {}
//--------------------------------------------------------------------
rgba32(const rgba& c) :
r(value_type(c.r)), g(value_type(c.g)), b(value_type(c.b)), a(value_type(c.a)) {}
//--------------------------------------------------------------------
rgba32(const rgba8& c) :
r(value_type(c.r / 255.0)),
g(value_type(c.g / 255.0)),
b(value_type(c.b / 255.0)),
a(value_type(c.a / 255.0)) {}
//--------------------------------------------------------------------
rgba32(const srgba8& c) :
r(sRGB_conv<value_type>::rgb_from_sRGB(c.r)),
g(sRGB_conv<value_type>::rgb_from_sRGB(c.g)),
b(sRGB_conv<value_type>::rgb_from_sRGB(c.b)),
a(sRGB_conv<value_type>::alpha_from_sRGB(c.a)) {}
//--------------------------------------------------------------------
rgba32(const rgba16& c) :
r(value_type(c.r / 65535.0)),
g(value_type(c.g / 65535.0)),
b(value_type(c.b / 65535.0)),
a(value_type(c.a / 65535.0)) {}
//--------------------------------------------------------------------
operator rgba() const
{
return rgba(r, g, b, a);
}
//--------------------------------------------------------------------
operator rgba8() const
{
return rgba8(
uround(r * 255.0),
uround(g * 255.0),
uround(b * 255.0),
uround(a * 255.0));
}
//--------------------------------------------------------------------
operator srgba8() const
{
return srgba8(
sRGB_conv<value_type>::rgb_to_sRGB(r),
sRGB_conv<value_type>::rgb_to_sRGB(g),
sRGB_conv<value_type>::rgb_to_sRGB(b),
sRGB_conv<value_type>::alpha_to_sRGB(a));
}
//--------------------------------------------------------------------
operator rgba16() const
{
return rgba8(
uround(r * 65535.0),
uround(g * 65535.0),
uround(b * 65535.0),
uround(a * 65535.0));
}
//--------------------------------------------------------------------
static AGG_INLINE double to_double(value_type a)
{
return a;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type from_double(double a)
{
return value_type(a);
}
//--------------------------------------------------------------------
static AGG_INLINE value_type empty_value()
{
return 0;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type full_value()
{
return 1;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_transparent() const
{
return a <= 0;
}
//--------------------------------------------------------------------
AGG_INLINE bool is_opaque() const
{
return a >= 1;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type invert(value_type x)
{
return 1 - x;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type multiply(value_type a, value_type b)
{
return value_type(a * b);
}
//--------------------------------------------------------------------
static AGG_INLINE value_type demultiply(value_type a, value_type b)
{
return (b == 0) ? 0 : value_type(a / b);
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downscale(T a)
{
return a;
}
//--------------------------------------------------------------------
template<typename T>
static AGG_INLINE T downshift(T a, unsigned n)
{
return n > 0 ? a / (1 << n) : a;
}
//--------------------------------------------------------------------
static AGG_INLINE value_type mult_cover(value_type a, cover_type b)
{
return value_type(a * b / cover_mask);
}
//--------------------------------------------------------------------
static AGG_INLINE cover_type scale_cover(cover_type a, value_type b)
{
return cover_type(uround(a * b));
}
//--------------------------------------------------------------------
// Interpolate p to q by a, assuming q is premultiplied by a.
static AGG_INLINE value_type prelerp(value_type p, value_type q, value_type a)
{
return (1 - a) * p + q; // more accurate than "p + q - p * a"
}
//--------------------------------------------------------------------
// Interpolate p to q by a.
static AGG_INLINE value_type lerp(value_type p, value_type q, value_type a)
{
// The form "p + a * (q - p)" avoids a multiplication, but may produce an
// inaccurate result. For example, "p + (q - p)" may not be exactly equal
// to q. Therefore, stick to the basic expression, which at least produces
// the correct result at either extreme.
return (1 - a) * p + a * q;
}
//--------------------------------------------------------------------
self_type& clear()
{
r = g = b = a = 0;
return *this;
}
//--------------------------------------------------------------------
self_type& transparent()
{
a = 0;
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& opacity(double a_)
{
if (a_ < 0) a = 0;
else if (a_ > 1) a = 1;
else a = value_type(a_);
return *this;
}
//--------------------------------------------------------------------
double opacity() const
{
return a;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& premultiply()
{
if (a < 1)
{
if (a <= 0)
{
r = g = b = 0;
}
else
{
r *= a;
g *= a;
b *= a;
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type& demultiply()
{
if (a < 1)
{
if (a <= 0)
{
r = g = b = 0;
}
else
{
r /= a;
g /= a;
b /= a;
}
}
return *this;
}
//--------------------------------------------------------------------
AGG_INLINE self_type gradient(const self_type& c, double k) const
{
self_type ret;
ret.r = value_type(r + (c.r - r) * k);
ret.g = value_type(g + (c.g - g) * k);
ret.b = value_type(b + (c.b - b) * k);
ret.a = value_type(a + (c.a - a) * k);
return ret;
}
//--------------------------------------------------------------------
AGG_INLINE void add(const self_type& c, unsigned cover)
{
if (cover == cover_mask)
{
if (c.is_opaque())
{
*this = c;
return;
}
else
{
r += c.r;
g += c.g;
b += c.b;
a += c.a;
}
}
else
{
r += mult_cover(c.r, cover);
g += mult_cover(c.g, cover);
b += mult_cover(c.b, cover);
a += mult_cover(c.a, cover);
}
if (a > 1) a = 1;
if (r > a) r = a;
if (g > a) g = a;
if (b > a) b = a;
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_dir(const GammaLUT& gamma)
{
r = gamma.dir(r);
g = gamma.dir(g);
b = gamma.dir(b);
}
//--------------------------------------------------------------------
template<class GammaLUT>
AGG_INLINE void apply_gamma_inv(const GammaLUT& gamma)
{
r = gamma.inv(r);
g = gamma.inv(g);
b = gamma.inv(b);
}
//--------------------------------------------------------------------
static self_type no_color() { return self_type(0,0,0,0); }
//--------------------------------------------------------------------
static self_type from_wavelength(double wl, double gamma = 1)
{
return self_type(rgba::from_wavelength(wl, gamma));
}
};
}
#endif