diff options
| -rw-r--r-- | Makefile | 1 | ||||
| -rw-r--r-- | libglitter.h | 44 | ||||
| -rw-r--r-- | libglitter_reorder_rasters.c | 15 |
3 files changed, 59 insertions, 1 deletions
@@ -34,6 +34,7 @@ OBJ =\ libglitter_get_colour_space_conversion_matrix_float.o\ libglitter_per_channel_desaturate_double.o\ libglitter_per_channel_desaturate_float.o\ + libglitter_reorder_rasters.o\ libglitter_split_uint32_raster.o\ libglitter_split_uint64_raster.o\ libglitter_update_render_context.o diff --git a/libglitter.h b/libglitter.h index 4e339e7..79af0fd 100644 --- a/libglitter.h +++ b/libglitter.h @@ -79,6 +79,27 @@ typedef struct libglitter_render_context LIBGLITTER_RENDER_CONTEXT; /** + * Output primary colour + */ +enum libglitter_colour { + /** + * Red primary colour + */ + LIBGLITTER_CHANNEL_RED = 0, + + /** + * Green primary colour + */ + LIBGLITTER_CHANNEL_GREEN = 1, + + /** + * Blue primary colour + */ + LIBGLITTER_CHANNEL_BLUE = 2 +}; + + +/** * Attempt to enable hardware acceleration * * Currently this function doesn't do anything but call the @@ -251,7 +272,28 @@ void libglitter_compose_uint8(uint8_t **, const uint8_t *restrict, size_t, size_ size_t, size_t, const LIBGLITTER_RENDER_CONTEXT *); -/* TODO add function for reordering rasters according to the subpixel layout */ +/** + * Reorders a set of three rasters + * + * When the function `libglitter_create_render_context` is called, + * the parameter named `cellmap` contains the values 0, 1, and 2, + * representing different channels: indices in the raster array. + * The values are not necessarily 0 for red, 1 for green, and 2 for blue, + * but this function lets the user reorder the rasters so that before + * calling this function the rasters may be in this order, but when + * call a `libglitter_compose_*` function after calling this function, + * that function will write to the correct rasters + * + * @param rasters The array of the three rasters, on input the rasters + * shall be in the order (0) red, (1) green, (2) blue; + * the function will reorder them + * @param colour1 The colour of the channel value 0 represents in `cellmap` + * @param colour2 The colour of the channel value 1 represents in `cellmap` + * @param colour3 The colour of the channel value 2 represents in `cellmap` + * + * The values `colour1`, `colour2`, `colour3` must be valid but distinct + */ +void libglitter_reorder_rasters(void **, enum libglitter_colour, enum libglitter_colour, enum libglitter_colour); /** diff --git a/libglitter_reorder_rasters.c b/libglitter_reorder_rasters.c new file mode 100644 index 0000000..5df590e --- /dev/null +++ b/libglitter_reorder_rasters.c @@ -0,0 +1,15 @@ +/* See LICENSE file for copyright and license details. */ +#include "common.h" + + +void +libglitter_reorder_rasters(void **rasters, enum libglitter_colour colour1, + enum libglitter_colour colour2, enum libglitter_colour colour3) +{ + void *channel1 = rasters[colour1]; + void *channel2 = rasters[colour2]; + void *channel3 = rasters[colour3]; + rasters[0] = channel1; + rasters[1] = channel2; + rasters[2] = channel3; +} |