diff options
| -rw-r--r-- | .gitignore | 2 | ||||
| -rw-r--r-- | libdimension-png/png.c | 26 | ||||
| -rw-r--r-- | libdimension/color.c | 103 |
3 files changed, 66 insertions, 65 deletions
@@ -19,7 +19,7 @@ Makefile.in # Files created by `make check' /tests/png -/tests/dimension.png +/tests/dimension*.png # Files and folders created by libtool .libs/ diff --git a/libdimension-png/png.c b/libdimension-png/png.c index dbcd21a..49f1d6c 100644 --- a/libdimension-png/png.c +++ b/libdimension-png/png.c @@ -83,22 +83,28 @@ dmnsn_png_write_canvas(const dmnsn_canvas *canvas, FILE *file) pixel = canvas->pixels + (height - y - 1)*width + x; sRGB = dmnsn_sRGB_from_color(*pixel); - if (sRGB.R < 1.0) { - row[4*x] = sRGB.R*UINT16_MAX; - } else { + if (sRGB.R <= 0.0) { + row[4*x] = 0; + } else if (sRGB.R >= 1.0) { row[4*x] = UINT16_MAX; + } else { + row[4*x] = sRGB.R*UINT16_MAX; } - if (sRGB.G < 1.0) { - row[4*x + 1] = sRGB.G*UINT16_MAX; - } else { + if (sRGB.G <= 0.0) { + row[4*x + 1] = 0; + } else if (sRGB.G >= 1.0) { row[4*x + 1] = UINT16_MAX; - } - - if (sRGB.B < 1.0) { - row[4*x + 2] = sRGB.B*UINT16_MAX; } else { + row[4*x + 1] = sRGB.G*UINT16_MAX; + } + + if (sRGB.B <= 0.0) { + row[4*x + 2] = 0; + } else if (sRGB.B >= 1.0) { row[4*x + 2] = UINT16_MAX; + } else { + row[4*x + 2] = sRGB.B*UINT16_MAX; } row[4*x + 3] = (pixel->filter + pixel->trans)*UINT16_MAX; diff --git a/libdimension/color.c b/libdimension/color.c index bbde48d..e1450ac 100644 --- a/libdimension/color.c +++ b/libdimension/color.c @@ -26,17 +26,24 @@ dmnsn_CIE_XYZ whitepoint = { 0.9505, 1, 1.089 }; dmnsn_color dmnsn_color_from_XYZ(dmnsn_CIE_XYZ XYZ) { - dmnsn_color ret = { XYZ.X, XYZ.Y, XYZ.Z, 0.0, 0.0 }; + dmnsn_color ret; + ret.X = XYZ.X; + ret.Y = XYZ.Y; + ret.Z = XYZ.Z; + ret.filter = 0.0; + ret.trans = 0.0; return ret; } dmnsn_color dmnsn_color_from_xyY(dmnsn_CIE_xyY xyY) { - dmnsn_color ret = { xyY.Y*xyY.x/xyY.y, - xyY.Y, - xyY.Y*(1.0 - xyY.x - xyY.Y)/xyY.y, - 0.0, 0.0 }; + dmnsn_color ret; + ret.X = xyY.Y*xyY.x/xyY.y; + ret.Y = xyY.Y; + ret.Z = xyY.Y*(1.0 - xyY.x - xyY.Y)/xyY.y; + ret.filter = 0.0; + ret.trans = 0.0; return ret; } @@ -86,12 +93,7 @@ dmnsn_color_from_Luv(dmnsn_CIE_Luv Luv, dmnsn_CIE_XYZ white) return ret; } -dmnsn_color -dmnsn_color_from_sRGB(dmnsn_sRGB sRGB) -{ - double Rlinear, Glinear, Blinear; /* Linear RGB values - no gamma */ - dmnsn_color ret; - +static double sRGB_Cinv(double CsRGB) { /* * If C represents R, G, and B, then the Clinear values are now found as * follows: @@ -100,24 +102,22 @@ dmnsn_color_from_sRGB(dmnsn_sRGB sRGB) * Clinear = { 1/2.4 * { ((Csrgb + 0.055)/1.055) , Csrgb > 0.04045 */ - - if (sRGB.R <= 0.04045) { - Rlinear = sRGB.R/19.92; + if (CsRGB <= 0.040449936) { + return CsRGB/12.92; } else { - Rlinear = pow((sRGB.R + 0.055)/1.055, 2.4); + return pow((CsRGB + 0.055)/1.055, 2.4); } +} - if (sRGB.G <= 0.04045) { - Glinear = sRGB.G/19.92; - } else { - Glinear = pow((sRGB.G + 0.055)/1.055, 2.4); - } +dmnsn_color +dmnsn_color_from_sRGB(dmnsn_sRGB sRGB) +{ + double Rlinear, Glinear, Blinear; /* Linear RGB values - no gamma */ + dmnsn_color ret; - if (sRGB.B <= 0.04045) { - Blinear = sRGB.B/19.92; - } else { - Blinear = pow((sRGB.B + 0.055)/1.055, 2.4); - } + Rlinear = sRGB_Cinv(sRGB.R); + Glinear = sRGB_Cinv(sRGB.G); + Blinear = sRGB_Cinv(sRGB.B); /* * Now, the linear conversion. Expressed as matrix multiplication, it looks @@ -127,10 +127,12 @@ dmnsn_color_from_sRGB(dmnsn_sRGB sRGB) * [Y] = [0.2126 0.7152 0.0722]*[Glinear] * [X] [0.0193 0.1192 0.9505] [Blinear] */ - - ret.X = 0.4124*Rlinear + 0.3576*Glinear + 0.1805*Blinear; - ret.Y = 0.2126*Rlinear + 0.7152*Glinear + 0.0722*Blinear; - ret.Z = 0.0193*Rlinear + 0.1192*Glinear + 0.9505*Blinear; + ret.X = 0.4123808838268995*Rlinear + 0.3575728355732478*Blinear + + 0.1804522977447919*Glinear; + ret.Y = 0.2126198631048975*Rlinear + 0.7151387878413206*Blinear + + 0.0721499433963131*Glinear; + ret.Z = 0.0193434956789248*Rlinear + 0.1192121694056356*Blinear + + 0.9505065664127130*Glinear; ret.filter = 0.0; ret.trans = 0.0; @@ -191,6 +193,21 @@ dmnsn_Luv_from_color(dmnsn_color color, dmnsn_CIE_XYZ white) return ret; } +static double sRGB_C(double Clinear) { + /* + * If C represents R, G, and B, then the sRGB values are now found as follows: + * + * { 12.92*Clinear, Clinear <= 0.0031308 + * Csrgb = { 1/2.4 + * { (1.055)*Clinear - 0.055, Clinear > 0.0031308 + */ + if (Clinear <= 0.0031308) { + return 12.92*Clinear; + } else { + return 1.055*pow(Clinear, 1.0/2.4) - 0.055; + } +} + dmnsn_sRGB dmnsn_sRGB_from_color(dmnsn_color color) { @@ -209,31 +226,9 @@ dmnsn_sRGB_from_color(dmnsn_color color) Glinear = -0.9692*color.X + 1.8760*color.Y + 0.0416*color.Z; Blinear = 0.0556*color.X - 0.2040*color.Y + 1.0570*color.Z; - /* - * If C represents R, G, and B, then the sRGB values are now found as follows: - * - * { 12.92*Clinear, Clinear <= 0.0031308 - * Csrgb = { 1/2.4 - * { (1.055)*Clinear - 0.055, Clinear > 0.0031308 - */ - - if (Rlinear <= 0.0031308) { - ret.R = 12.92*Rlinear; - } else { - ret.R = 1.055*pow(Rlinear, 1.0/2.4) - 0.055; - } - - if (Glinear <= 0.0031308) { - ret.G = 12.92*Glinear; - } else { - ret.G = 1.055*pow(Glinear, 1.0/2.4) - 0.055; - } - - if (Blinear <= 0.0031308) { - ret.B = 12.92*Blinear; - } else { - ret.B = 1.055*pow(Blinear, 1.0/2.4) - 0.055; - } + ret.R = sRGB_C(Rlinear); + ret.G = sRGB_C(Glinear); + ret.B = sRGB_C(Blinear); return ret; } |