diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libclut.h | 82 | ||||
| -rw-r--r-- | src/test.c | 2 |
2 files changed, 57 insertions, 27 deletions
diff --git a/src/libclut.h b/src/libclut.h index 60ef414..e8a8fc7 100644 --- a/src/libclut.h +++ b/src/libclut.h @@ -20,6 +20,7 @@ #include <stddef.h> #include <string.h> #include <math.h> +#include <float.h> @@ -360,11 +361,6 @@ static inline int libclut_0__(double x) { return libclut_eq__(x, 0); } * only way to adjust the blackpoint on many LCD * monitors. * - * Warning. Stops that is too close 0 when using - * floating-point values, get generate overly - * large results. Values too close to `max` when - * using floating-point values, get generate `nan`. - * * None of the parameter may have side-effects. * * Requires linking with '-lm'. @@ -379,28 +375,60 @@ static inline int libclut_0__(double x) { return libclut_eq__(x, 0); } * @param gp Pointer to the sigmoid parameter for the green curve. `NULL` for no adjustment. * @param bp Pointer to the sigmoid parameter for the blue curve. `NULL` for no adjustment. */ -#define libclut_sigmoid(clut, max, type, rp, gp, bp) \ - do \ - { \ - double *gcc_6_1_1_workaround, s__, m__ = (double)(max); \ - size_t i__; \ - const double h__ = (double)5 / 10; \ - gcc_6_1_1_workaround = rp; \ - if (gcc_6_1_1_workaround) \ - for (i__ = 0, s__ = *gcc_6_1_1_workaround; i__ < (clut)->red_size; i__++) \ - if ((clut)->red[i__] && ((clut)->red[i__] != (max))) \ - (clut)->red[i__] = (type)(m__ * (h__ - log(m__ / (clut)->red[i__] - 1) / s__)); \ - gcc_6_1_1_workaround = gp; \ - if (gcc_6_1_1_workaround) \ - for (i__ = 0, s__ = *gcc_6_1_1_workaround; i__ < (clut)->green_size; i__++) \ - if ((clut)->green[i__] && ((clut)->green[i__] != (max))) \ - (clut)->green[i__] = (type)(m__ * (h__ - log(m__ / (clut)->green[i__] - 1) / s__)); \ - gcc_6_1_1_workaround = bp; \ - if (gcc_6_1_1_workaround) \ - for (i__ = 0, s__ = *gcc_6_1_1_workaround; i__ < (clut)->blue_size; i__++) \ - if ((clut)->blue[i__] && ((clut)->blue[i__] != (max))) \ - (clut)->blue[i__] = (type)(m__ * (h__ - log(m__ / (clut)->blue[i__] - 1) / s__)); \ - } \ +#define libclut_sigmoid(clut, max, type, rp, gp, bp) \ + do \ + { \ + double *gcc_6_1_1_workaround, m__ = (double)(max); \ + const double h__ = (double)5 / 10; \ + gcc_6_1_1_workaround = rp; \ + if (gcc_6_1_1_workaround) \ + libclut_sigmoid__(clut, max, type, red); \ + gcc_6_1_1_workaround = gp; \ + if (gcc_6_1_1_workaround) \ + libclut_sigmoid__(clut, max, type, green); \ + gcc_6_1_1_workaround = bp; \ + if (gcc_6_1_1_workaround) \ + libclut_sigmoid__(clut, max, type, blue); \ + } \ + while (0) + + +/** + * Apply S-curve correction on the colour curves. + * This is intended for fine tuning LCD monitors, + * 4.5 is good value start start testing at. + * You would probably like to use rgb_limits before + * this to adjust the blackpoint as that is the + * only way to adjust the blackpoint on many LCD + * monitors. + * + * None of the parameter may have side-effects. + * + * Requires linking with '-lm'. + * + * Intended for internal use. + * + * @param clut Pointer to the gamma ramps, must have the arrays + * `red`, `green`, and `blue`, and the scalars + * `red_size`, `green_size`, and `blue_size`. Ramp + * structures from libgamma or libcoopgamma can be used. + * @param max The maximum value on each stop in the ramps. + * @param type The data type used for each stop in the ramps. + * @param channel The channel, must be either "red", "green", or "blue". + */ +#define libclut_sigmoid__(clut, max, type, channel) \ + do \ + { \ + double s__ = *gcc_6_1_1_workaround, l__; \ + size_t i__; \ + for (i__ = 0; i__ < (clut)->channel##_size; i__++) \ + { \ + l__ = log(m__ / (clut)->red[i__] - 1); \ + if (isnan(l__) || isinf(l__)) \ + l__ = 37.024483 * (isinf(l__) > 0 ? +1 : -1); \ + (clut)->red[i__] = (type)(m__ * (h__ - l__ / s__)); \ + } \ + } \ while (0) @@ -252,6 +252,8 @@ int main(int argc, char *argv[]) t2.blue[i] = t2.green[i] = t2.red[i] = (uint16_t)(x * UINT16_MAX); } libclut_sigmoid(&t1, UINT16_MAX, uint16_t, ¶m, ¶m, ¶m); + t1.blue[0] = t1.green[0] = t1.red[0] = t2.red[0]; + t1.blue[255] = t1.green[255] = t1.red[255] = t2.red[255]; if (clutcmp(&t1, &t2, 0)) printf("libclut_sigmoid failed\n"), rc = 1; |