wlroots/include/render/color.h
2024-08-24 23:25:08 -04:00

85 lines
2.6 KiB
C

#ifndef RENDER_COLOR_H
#define RENDER_COLOR_H
#include <stdint.h>
#include <wlr/util/addon.h>
enum wlr_color_transform_type {
COLOR_TRANSFORM_SRGB,
COLOR_TRANSFORM_LUT_3D,
COLOR_TRANSFORM_LUT_3x1D,
};
struct wlr_color_transform {
int ref_count;
struct wlr_addon_set addons; // per-renderer helper state
enum wlr_color_transform_type type;
};
/**
* The formula is approximated via a 3D look-up table. A 3D LUT is a
* three-dimensional array where each element is an RGB triplet. The flat lut_3d
* array has a length of dim_len³.
*
* Color channel values in the range [0.0, 1.0] are mapped linearly to
* 3D LUT indices such that 0.0 maps exactly to the first element and 1.0 maps
* exactly to the last element in each dimension.
*
* The offset of the RGB triplet given red, green and blue indices r_index,
* g_index and b_index is:
*
* offset = 3 * (r_index + dim_len * g_index + dim_len * dim_len * b_index)
*/
struct wlr_color_transform_lut3d {
struct wlr_color_transform base;
float *lut_3d;
size_t dim_len;
};
/**
* This is a color transform that is specified by three seperate ramps that
* modify the RGB values individually. This means that this color transform type
* cannot be used to create a transform that can infruence color channels
* depending on the values of other color channels.
*
* This color transform is modeled off of the wlr-gamma-control-unstable-v1
* wayland protocol.
*
* The memory layout of this type requires that the r, g, b color channel ramps
* are inline in memory. A ramp value can be retrieved from memory:
*
* offset = dim_len * rgb_channel_index + ramp_index
*
* This is an offset into the `r` pointer and can be used to retrieve the ramps
* from the other channels as the ramps are linear in memory. The three pointers
* are given for convenience.
*
* Note that when freeing the color transform, only the `r` channel is freed as
* a it's expected that a single malloc will allocate all three channels at once.
*/
struct wlr_color_transform_lut3x1d {
struct wlr_color_transform base;
uint16_t *r;
uint16_t *g;
uint16_t *b;
size_t ramp_size;
};
/**
* Gets a wlr_color_transform_lut3d from a generic wlr_color_transform.
* Asserts that the base type is COLOR_TRANSFORM_LUT_3D
*/
struct wlr_color_transform_lut3d *wlr_color_transform_lut3d_from_base(
struct wlr_color_transform *tr);
/**
* Gets a wlr_color_transform_lut3x1d from a generic wlr_color_transform.
* Asserts that the base type is COLOR_TRANSFORM_LUT_3x1D
*/
struct wlr_color_transform_lut3x1d *wlr_color_transform_lut3x1d_from_base(
struct wlr_color_transform *tr);
#endif