diff options
Diffstat (limited to 'src/libclut.c')
| -rw-r--r-- | src/libclut.c | 103 |
1 files changed, 82 insertions, 21 deletions
diff --git a/src/libclut.c b/src/libclut.c index 9395c71..52c9615 100644 --- a/src/libclut.c +++ b/src/libclut.c @@ -647,8 +647,10 @@ static int get_conversion_matrix(const libclut_rgb_colour_space_t* cs, libclut_c * Create a matrix for converting values between * two RGB colour spaces. * - * @param from The input colour space, the Y-component is only necessary for the whitepoint. - * @param to The output colour space, the Y-component is only necessary for the whitepoint. + * @param from The input colour space, the Y-component is only necessary + * for the white point, `NULL` for CIE XYZ. + * @param to The output colour space, the Y-component is only necessary + * for the white point, `NULL` for CIE XYZ. * @param M Output matrix for conversion from `from` to `to`. * @param Minv Output matrix for conversion from `to` to `from`, may be `NULL`. * @return Zero on success, -1 on error. @@ -662,24 +664,44 @@ int libclut_model_get_rgb_conversion_matrix(const libclut_rgb_colour_space_t* fr { libclut_colour_space_conversion_matrix_t A, B; - if (get_conversion_matrix(from, A)) - return -1; - if (get_conversion_matrix(to, M)) - return -1; - if (!invert(M, B)) - return errno = EINVAL, -1; - - M[0][0] = B[0][0] * A[0][0] + B[0][1] * A[1][0] + B[0][2] * A[2][0]; - M[0][1] = B[0][0] * A[0][1] + B[0][1] * A[1][1] + B[0][2] * A[2][1]; - M[0][2] = B[0][0] * A[0][2] + B[0][1] * A[1][2] + B[0][2] * A[2][2]; - - M[1][0] = B[1][0] * A[0][0] + B[1][1] * A[1][0] + B[1][2] * A[2][0]; - M[1][1] = B[1][0] * A[0][1] + B[1][1] * A[1][1] + B[1][2] * A[2][1]; - M[1][2] = B[1][0] * A[0][2] + B[1][1] * A[1][2] + B[1][2] * A[2][2]; + if (from != NULL) + { + if (get_conversion_matrix(from, A)) + return -1; + } + else + { + A[0][0] = A[1][1] = A[2][2] = 1; + A[0][1] = A[1][0] = A[2][0] = 0; + A[0][2] = A[1][2] = A[2][1] = 0; + } - M[2][0] = B[2][0] * A[0][0] + B[2][1] * A[1][0] + B[2][2] * A[2][0]; - M[2][1] = B[2][0] * A[0][1] + B[2][1] * A[1][1] + B[2][2] * A[2][1]; - M[2][2] = B[2][0] * A[0][2] + B[2][1] * A[1][2] + B[2][2] * A[2][2]; + if (to != NULL) + { + if (get_conversion_matrix(to, M)) + return -1; + if (!invert(M, B)) + return errno = EINVAL, -1; + + if (from != NULL) + { + M[0][0] = B[0][0] * A[0][0] + B[0][1] * A[1][0] + B[0][2] * A[2][0]; + M[0][1] = B[0][0] * A[0][1] + B[0][1] * A[1][1] + B[0][2] * A[2][1]; + M[0][2] = B[0][0] * A[0][2] + B[0][1] * A[1][2] + B[0][2] * A[2][2]; + + M[1][0] = B[1][0] * A[0][0] + B[1][1] * A[1][0] + B[1][2] * A[2][0]; + M[1][1] = B[1][0] * A[0][1] + B[1][1] * A[1][1] + B[1][2] * A[2][1]; + M[1][2] = B[1][0] * A[0][2] + B[1][1] * A[1][2] + B[1][2] * A[2][2]; + + M[2][0] = B[2][0] * A[0][0] + B[2][1] * A[1][0] + B[2][2] * A[2][0]; + M[2][1] = B[2][0] * A[0][1] + B[2][1] * A[1][1] + B[2][2] * A[2][1]; + M[2][2] = B[2][0] * A[0][2] + B[2][1] * A[1][2] + B[2][2] * A[2][2]; + } + else + memcpy(M, B, sizeof(B)); + } + else + memcpy(M, A, sizeof(A)); if (Minv != NULL) { @@ -694,9 +716,8 @@ int libclut_model_get_rgb_conversion_matrix(const libclut_rgb_colour_space_t* fr /** * Convert an RGB colour into another RGB colour space. - * None of the parameter may have side-effects. * - * Both RGB colour space must have same gamma functions as RGB. + * Both RGB colour spaces must have same gamma functions as sRGB. * * @param r The red component of the colour to convert. * @param g The green component of the colour to convert. @@ -712,3 +733,43 @@ void (libclut_model_convert_rgb)(double r, double g, double b, libclut_colour_sp libclut_model_convert_rgb(r, g, b, M, out_r, out_g, out_b); } + +/** + * Convert an RGB colour of a custom RGB colour space to CIE XYZ. + * + * The RGB colour space must have same gamma functions as sRGB. + * + * @param r The red component. + * @param g The green component. + * @param b The blue component. + * @param M Conversion matrix, create with `libclut_model_get_rgb_conversion_matrix`. + * @param x Output parameter for the X component. + * @param y Output parameter for the Y component. + * @param z Output parameter for the Z component. + */ +void (libclut_model_rgb_to_ciexyz)(double r, double g, double b, libclut_colour_space_conversion_matrix_t M, + double* x, double* y, double* z) +{ + libclut_model_rgb_to_ciexyz(r, g, b, M, x, y, z); +} + + +/** + * Convert a CIE XYZ colour to a custom RGB colour space. + * + * The RGB colour space must have same gamma functions as sRGB. + * + * @param x The X component. + * @param y The Y component. + * @param z The Z component. + * @param M Conversion matrix, create with `libclut_model_get_rgb_conversion_matrix`. + * @param r Output parameter for the red component. + * @param g Output parameter for the green component + * @param b Output parameter for the blue component. + */ +void (libclut_model_ciexyz_to_rgb)(double x, double y, double z, libclut_colour_space_conversion_matrix_t M, + double* r, double* g, double* b) +{ + libclut_model_ciexyz_to_rgb(x, y, z, M, r, g, b); +} + |