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-rw-r--r--src/convert.c68
1 files changed, 46 insertions, 22 deletions
diff --git a/src/convert.c b/src/convert.c
index 0ca9ef1..e229583 100644
--- a/src/convert.c
+++ b/src/convert.c
@@ -84,9 +84,9 @@ static void to_rgb(const libcolour_colour_t* restrict from, libcolour_rgb_t* res
to->B = pow(to->B, 1 / to->gamma);
break;
case LIBCOLOUR_ENCODING_TYPE_REGULAR:
- to->R <= to->transition ? to->slope * to->R : (1 + to->offset) * pow(to->R, 1 / to->gamma) - to->offset;
- to->G <= to->transition ? to->slope * to->G : (1 + to->offset) * pow(to->G, 1 / to->gamma) - to->offset;
- to->B <= to->transition ? to->slope * to->B : (1 + to->offset) * pow(to->B, 1 / to->gamma) - to->offset;
+ to->R = to->R <= to->transition ? to->slope * to->R : (1 + to->offset) * pow(to->R, 1 / to->gamma) - to->offset;
+ to->G = to->G <= to->transition ? to->slope * to->G : (1 + to->offset) * pow(to->G, 1 / to->gamma) - to->offset;
+ to->B = to->B <= to->transition ? to->slope * to->B : (1 + to->offset) * pow(to->B, 1 / to->gamma) - to->offset;
break;
case LIBCOLOUR_ENCODING_TYPE_CUSTOM:
to->R = (to->to_encoded_red)(to->R);
@@ -107,9 +107,9 @@ static void to_rgb(const libcolour_colour_t* restrict from, libcolour_rgb_t* res
to->B = pow(to->B, to->gamma);
break;
case LIBCOLOUR_ENCODING_TYPE_REGULAR:
- to->R <= to->transitioninv ? to->R * to->slope : pow((to->R + to->offset) / (1 + to->offset), to->gamma);
- to->G <= to->transitioninv ? to->G * to->slope : pow((to->G + to->offset) / (1 + to->offset), to->gamma);
- to->B <= to->transitioninv ? to->B * to->slope : pow((to->B + to->offset) / (1 + to->offset), to->gamma);
+ to->R = to->R <= to->transitioninv ? to->R * to->slope : pow((to->R + to->offset) / (1 + to->offset), to->gamma);
+ to->G = to->G <= to->transitioninv ? to->G * to->slope : pow((to->G + to->offset) / (1 + to->offset), to->gamma);
+ to->B = to->B <= to->transitioninv ? to->B * to->slope : pow((to->B + to->offset) / (1 + to->offset), to->gamma);
break;
case LIBCOLOUR_ENCODING_TYPE_CUSTOM:
to->R = (to->to_decoded_red)(to->R);
@@ -128,19 +128,33 @@ static void to_rgb(const libcolour_colour_t* restrict from, libcolour_rgb_t* res
static void ciexyz_to_srgb(const libcolour_ciexyz_t* restrict from, libcolour_srgb_t* restrict to)
{
double X = from->X, Y = from->Y, Z = from->Z;
- to->R = 3.240450 * X + -1.537140 * Y + -0.4985320 * Z;
- to->G = -0.969266 * X + 1.876010 * Y + 0.0415561 * Z;
- to->B = 0.0556434 * X + -0.204026 * Y + 1.0572300 * Z;
+#define MULTIPLY(CX, CY, CZ) ((CX) * X + (CY) * Y + (CZ) * Z)
+ to->R = MULTIPLY(3.240446254647737500675930277794, -1.537134761820080575134284117667, -0.498530193022728718155178739835);
+ to->G = MULTIPLY(-0.969266606244679751469561779231, 1.876011959788370209167851498933, 0.041556042214430065351304932619);
+ to->B = MULTIPLY(0.055643503564352832235773149705, -0.204026179735960239147729566866, 1.057226567722703292062647051353);
+#undef MULTIPLY
}
-static inline double srgb_encode(double x)
+static inline double srgb_encode(double t)
{
- return x <= 0.0031306684425217108 ? 12.92 * x : 1.055 * pow(x, 1 / 2.4) - 0.055;
+ double sign = 1;
+ if (t < 0) {
+ t = -t;
+ sign = -1;
+ }
+ t = t <= 0.0031306684425217108 ? 12.92 * t : 1.055 * pow(t, 1 / 2.4) - 0.055;
+ return t * sign;
}
-static inline double srgb_decode(double x)
+static inline double srgb_decode(double t)
{
- return x <= 0.040448236277380506 ? x / 12.92 : pow((x + 0.055) / 1.055, 2.4);
+ double sign = 1;
+ if (t < 0) {
+ t = -t;
+ sign = -1;
+ }
+ t = t <= 0.040448236277380506 ? t / 12.92 : pow((t + 0.055) / 1.055, 2.4);
+ return t * sign;
}
static void srgb_to_srgb(const libcolour_srgb_t* restrict from, libcolour_srgb_t* restrict to)
@@ -161,9 +175,13 @@ static void srgb_to_srgb(const libcolour_srgb_t* restrict from, libcolour_srgb_t
static void yiq_to_srgb(const libcolour_yiq_t* restrict from, libcolour_srgb_t* restrict to)
{
double Y = from->Y, I = from->I, Q = from->Q;
- to->R = Y + I * 0.956 + Q * 0.621;
- to->G = Y - I * 0.272 - Q * 0.647;
- to->B = Y - I * 1.106 + Q * 1.703;
+ to->R = Y + I * 0.95629483232089407263032398986979387700557708740234 + Q * 0.62102512544472865396727456754888407886028289794922;
+ to->G = Y - I * 0.27212147408397735492968649850809015333652496337891 - Q * 0.64738095351761570928061928498209454119205474853516;
+ to->B = Y - I * 1.10698990856712820018969978264067322015762329101562 + Q * 1.70461497549882934343656870623817667365074157714844;
+ /* ⎛1 1000 cos 33° / 877 1000 sin 33° / 877 ⎞
+ ⎜1 9500 sin 33° / 24067 - 299000 * cos 33° / 514799 -9500 cos 33° / 24067 - 299000 * sin 33° / 514799⎟
+ ⎝1 -250 sin 33° / 123 250 cos 33° / 123 ⎠
+ */
}
static void ydbdr_to_srgb(const libcolour_ydbdr_t* restrict from, libcolour_srgb_t* restrict to)
@@ -318,9 +336,11 @@ static void srgb_to_ciexyz(const libcolour_srgb_t* restrict from, libcolour_ciex
} else {
R = from->R, G = from->G, B = from->B;
}
- to->X = 0.4124564 * R + 0.3575761 * G + 0.1804375 * B;
- to->Y = 0.2126729 * R + 0.7151522 * G + 0.0721750 * B;
- to->Z = 0.0193339 * R + 0.1191920 * G + 0.9503041 * B;
+#define MULTIPLIY(CR, CG, CB) ((CR) * R + (CG) * G + (CB) * B)
+ to->X = MULTIPLIY(0.412457445582367576708548995157, 0.357575865245515878143578447634, 0.180437247826399665973085006954);
+ to->Y = MULTIPLIY(0.212673370378408277403536885686, 0.715151730491031756287156895269, 0.072174899130559869164791564344);
+ to->Z = MULTIPLIY(0.019333942761673460208893260415, 0.119191955081838593666354597644, 0.950302838552371742508739771438);
+#undef MULTIPLIY
}
static void ciexyy_to_ciexyz(const libcolour_ciexyy_t* restrict from, libcolour_ciexyz_t* restrict to)
@@ -630,9 +650,13 @@ static void to_yiq(const libcolour_colour_t* restrict from, libcolour_yiq_t* res
r = tmp.srgb.R;
g = tmp.srgb.G;
b = tmp.srgb.B;
- to->Y = r * 0.29893602129377540 + g * 0.5870430744511212 + b * 0.11402090425510336;
- to->I = r * 0.59594574307079930 - g * 0.2743886357457892 - b * 0.32155710732501010;
- to->Q = r * 0.21149734030682846 - g * 0.5229106903029739 + b * 0.31141334999614540;
+ to->Y = r * 0.299 + g * 0.587 + b * 0.114;
+ to->I = r * 0.59571613491277464191853141528554260730743408203125 /* (0.877 cos 33°)(1 - 0.299) - (0.492 sin 33°)(-0.299) */
+ - g * 0.27445283783925644716106262421817518770694732666016 /* (0.877 cos 33°)(-0.587) - (0.492 sin 33°)(-0.587) */
+ - b * 0.32126329707351808373516632855171337723731994628906; /* (0.877 cos 33°)(-0.114) - (0.492 sin 33°)(1 - 0.114) */
+ to->Q = r * 0.21145640212011795888713550084503367543220520019531 /* (0.877 sin 33°)(1 - 0.299) + (0.492 cos 33°)(-0.299) */
+ - g * 0.52259104529161115593183239980135113000869750976562 /* (0.877 sin 33°)(-0.587) + (0.492 cos 33°)(-0.587) */
+ + b * 0.31113464317149330806699936147197149693965911865234; /* (0.877 sin 33°)(-0.114) + (0.492 cos 33°)(1 - 0.114) */
return;
}
}
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