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diff --git a/libglitter_get_colour_model_conversion_matrix_double.3 b/libglitter_get_colour_model_conversion_matrix_double.3 new file mode 100644 index 0000000..adf06e5 --- /dev/null +++ b/libglitter_get_colour_model_conversion_matrix_double.3 @@ -0,0 +1,124 @@ +.TH LIBGLITTER_GET_COLOUR_MODEL_CONVERSION_MATRIX_* 3 LIBGLITTER +.SH NAME +libglitter_get_colour_model_conversion_matrix_* - Create a column-major colour model conversion matrix +.SH SYNOPSIS +.LP +.nf +#include <libglitter.h> + +void libglitter_get_colour_model_conversion_matrix_double(double \fImatrix\fP[3][3], + double \fIc1x\fP, double \fIc1y\fP, + double \fIc2x\fP, double \fIc2y\fP, + double \fIc3x\fP, double \fIc3y\fP, + double \fIwhite_x\fP, double \fIwhite_y\fP, + double \fIwhite_Y\fP, int \fIxyz\fP, + double *\fIc1Yp\fP, double *\fIc2Yp\fP, + double *\fIc3Yp\fP); + +void libglitter_get_colour_model_conversion_matrix_float(float \fImatrix\fP[3][3], + float \fIc1x\fP, float \fIc1y\fP, + float \fIc2x\fP, float \fIc2y\fP, + float \fIc3x\fP, float \fIc3y\fP, + float \fIwhite_x\fP, float \fIwhite_y\fP, + float \fIwhite_Y\fP, int \fIxyz\fP, + float *\fIc1Yp\fP, float *\fIc2Yp\fP, + float *\fIc3Yp\fP); +.fi +.PP +Link with +.IR "-lglitter -lm" . +.SH DESCRIPTION +The +.BR libglitter_get_colour_model_conversion_matrix_double () +and +.BR libglitter_get_colour_model_conversion_matrix_float () +functions calculate the CIE XYZ values for an output's +primary colours from there chromas expressed as CIE xy +values (CIE xyY sans Y) and the output's whitepoint's +CIE xyY values. It is assumed that the output uses additive +colour mixing and that the blackpoint is perfect black. +After calculating the primary colours' CIE XYZ values, +the functions either output, to +.I matrix +a column-major conversion matrix from the output's colour +model to CIE XYZ (if +.I xyz +is non-zero) or a column-major conversion matrix from the +output's colour model to [0, 1]-normalised sRGB (otherwise). +.PP +The x and y values of the output's first primary colour +shall be input as the +.I c1x +and +.I c1y +arguments, the second primary colour's values as +.I c2x +and +.I c2y +and the third primary colour's values as +.I c3x +and +.IR c3y . +.PP +.IR white_x , +.IR white_y , +and +.IR white_Y +shall be the output's whitepoint's CIE xyY values +(x, y, and Y respectively). +.I white_Y +is normally 1, and if it is, and if the whitepoint is +also the D65 illuminant (which it usually is), the macro +.I LIBGLITTER_ILLUMINANT_D65 +can be used to specify these three arguments (it expands +into three arguments): +.RS +.nf + +void libglitter_get_colour_model_conversion_matrix_double(double \fImatrix\fP[3][3], + double \fIc1x\fP, double \fIc1y\fP, + double \fIc2x\fP, double \fIc2y\fP, + double \fIc3x\fP, double \fIc3y\fP, + LIBGLITTER_ILLUMINANT_D65, + int \fIxyz\fP, double *\fIc1Yp\fP, + double *\fIc2Yp\fP, double *\fIc3Yp\fP); + +void libglitter_get_colour_model_conversion_matrix_float(float \fImatrix\fP[3][3], + float \fIc1x\fP, float \fIc1y\fP, + float \fIc2x\fP, float \fIc2y\fP, + float \fIc3x\fP, float \fIc3y\fP, + LIBGLITTER_ILLUMINANT_D65, + int \fIxyz\fP, float *\fIc1Yp\fP, + float *\fIc2Yp\fP, float *\fIc3Yp\fP); +.fi +.RE +.PP +Unless +.I c1Yp +is +.IR NULL , +.I *c1Yp +is set to the first primary colour's CIE Y value. +Likewise, unless +.I c2Yp +is +.IR NULL , +.I *c2Yp +is set to the second primary colour's CIE Y value, +and unless +.I c3Yp +is +.IR NULL , +.I *c3Yp +is set to the third primary colour's CIE Y value, +.PP +The output's three primary colours not form a straight +line: they must render a three dimensional colour space. +.SH RETURN VALUES +None. +.SH ERRORS +None. +.SH SEE ALSO +.BR libglitter (7), +.BR libglitter_colour_model_convert_rasters_double (3), +.BR libglitter_desaturate_double (3) |