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| -rw-r--r-- | src/libclut.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/src/libclut.h b/src/libclut.h index 882bf12..78b1562 100644 --- a/src/libclut.h +++ b/src/libclut.h @@ -474,6 +474,51 @@ 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 black point as that is the + * only why to adjust the black point on many LCD + * monitors. + * + * None of the parameter may have side-effects. + * + * @param ramp 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 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 rp Pointer to the sigmoid parameter for the red curve. `NULL` for no adjustment. + * @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(ramp, max, type, rp, gp, bp) \ + do \ + { \ + double r__ = (rp) ? *(rp) : 0.0; \ + double g__ = (gp) ? *(gp) : 0.0; \ + double b__ = (bp) ? *(bp) : 0.0; \ + double m__ = (double)(max); \ + size_t i__; \ + if (rp) \ + for (i__ = 0; i++ < (ramp)->red_size; i__++) \ + if ((ramp)->red[i__] && ((ramp)->red[i__] != (max))) \ + (ramp)->red[i__] = (type)(m__ * (0.5 - log(m__ / (ramp)->red[i__] - 1.0) / r__)); \ + if (gp) \ + for (i__ = 0; i++ < (ramp)->green_size; i__++) \ + if ((ramp)->green[i__] && ((ramp)->green[i__] != (max))) \ + (ramp)->green[i__] = (type)(m__ * (0.5 - log(m__ / (ramp)->green[i__] - 1.0) / g__)); \ + if (bp) \ + for (i__ = 0; i++ < (ramp)->blue_size; i__++) \ + if ((ramp)->blue[i__] && ((ramp)->blue[i__] != (max))) \ + (ramp)->blue[i__] = (type)(m__ * (0.5 - log(m__ / (ramp)->blue[i__] - 1.0) / b__)); \ + } \ + while (0) + + #endif |