diff options
Diffstat (limited to '')
| -rw-r--r-- | libglitter.h | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/libglitter.h b/libglitter.h index d285104..277b7e4 100644 --- a/libglitter.h +++ b/libglitter.h @@ -87,6 +87,13 @@ */ #define LIBGLITTER_FEATURE_COLOUR_MODEL UINT64_C(0x0000000000000200) +/** + * The allocation will use at least one of the functions + * `libglitter_redistribute_energy_double`, and + * `libglitter_redistribute_energy_float` + */ +#define LIBGLITTER_FEATURE_REDISTRIBUTE UINT64_C(0x0000000000000400) + /** * The CIE xyY values of the D65 illuminant @@ -141,6 +148,7 @@ enum libglitter_colour { * - LIBGLITTER_FEATURE_UINT32_TYPE, * - LIBGLITTER_FEATURE_UINT16_TYPE, * - LIBGLITTER_FEATURE_UINT8_TYPE, + ' - LIBGLITTER_FEATURE_REDISTRIBUTE, * - LIBGLITTER_FEATURE_COMPOSE, * - LIBGLITTER_FEATURE_CU_DESATURATION, * - LIBGLITTER_FEATURE_PC_DESATURATION, and @@ -218,6 +226,86 @@ void libglitter_update_render_context(LIBGLITTER_RENDER_CONTEXT *, size_t); /** + * Apply a horizontal, 1-dimensional convolution kernel + * and a vertical, 1-dimensional convolution kernel + * (both are optional) to kernel to blur the text in + * order to reduce colour fringing + * + * Each raster shall be row-major ordered an shall + * have horizontally adjacent cells adjacent in memory: + * the is no space between the cells' memory areas if + * there is no horizontal space between them in the + * raster + * + * @param output Output subpixel raster, need not be initialised; + * this raster is latter used as the input raster + * for the `libglitter_compose_double` function. + * This raster is assumed to have the height + * `height + (vkernelsize - 1)` and the width + * `width + (hkernelsize - 1)`; the text will be + * offset from the top by `(vkernelsize - 1) / 2` + * cells downward and and from the left by + * `(hkernelsize - 1) / 2` cells rightward + * @param input Input subpixel raster; this raster must have + * a left padding and a right padding of + * `hkernel - 1` zero-initialised cells, as well + * as a top padding and a bottom padding of + * `vkernel - 1` zero-initialised cells. The + * the pointer itself shall point to the first + * pixel, the topmost and leftmost pixel that + * is not part of the padding. + * @param output_rowsize The number of cells a pointer to cell in + * `output` must be offset with to get to the + * cell on the next row but in the same column + * @param input_rowsize The number of cells a pointer to cell in + * `input` must be offset with to get to the + * cell on the next row but in the same column + * @param width The width of the input raster, excluding + * padding, in cells + * @param height The height of the input raster, excluding + * padding, in cells + * @param hkernelsize The size (number of elements) of `hkernel`; + * must be odd; if 1, `hkernel` is not applied + * @param vkernelsize The size (number of elements) of `vkernel`; + * must be odd; if 1, `vkernel` is not applied + * @param hkernel The horizontal convolution kernel; the sum + * of its elements shall be 1. It can be `NULL` + * if `hkernelsize` is 1, as it will not be + * applied + * @param vkernel The vertical convolution kernel; the sum + * of its elements shall be 1. It can be `NULL` + * if `vkernelsize` is 1, as it will not be + * applied + * + * If the input value of the `widthmul` parameter to the + * `libglitter_create_render_context` function is `1`, it + * the suggested `hkernel` is `{1.}`, otherwise the suggested + * `hkernel` is `{1/3., 1/3., 1/3.}`. Likewise, if the + * input value of the `heightmul` parameter to the + * `libglitter_create_render_context` function is `1`, it + * the suggested `vkernel` is `{1.}`, otherwise the suggested + * `vkernel` is `{1/3., 1/3., 1/3.}`. Of course user + * experimentation is required to find the best kernel. + */ +LIBGLITTER_GCC_ATTRS__(nonnull(1, 2)) +void libglitter_redistribute_energy_double(double *restrict output, const double *restrict input, + size_t output_rowsize, size_t input_rowsize, size_t width, + size_t height, size_t hkernelsize, size_t vkernelsize, + const double *hkernel, const double *vkernel); + +/** + * This value is identical to `libglitter_redistribute_energy_double`, + * apart from it parameter types, see `libglitter_redistribute_energy_double` + * for details about this function + */ +LIBGLITTER_GCC_ATTRS__(nonnull(1, 2)) +void libglitter_redistribute_energy_float(float *restrict output, const float *restrict input, + size_t output_rowsize, size_t input_rowsize, size_t width, + size_t height, size_t hkernelsize, size_t vkernelsize, + const float *hkernel, const float *vkernel); + + +/** * Create one raster per monitor colour from a raster of * subpixels (which may be further divided in the raster) * |