diff options
Diffstat (limited to 'librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h')
| -rw-r--r-- | librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h | 105 |
1 files changed, 101 insertions, 4 deletions
diff --git a/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h b/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h index fffeae7..97d57c3 100644 --- a/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h +++ b/librifunktionsteckensnittsglyfrasteriseringsprogrambiblioteket.h @@ -5,36 +5,133 @@ #include <stddef.h> +/** + * Object that the library draws on, is converted to + * an ink-level image using the `rtgrpblib_fill_shapes` + * function. This object also contain drawing + * configurations. + */ typedef struct rtgrpblib_raster RTGRPBLIB_RASTER; +/** + * Create a buffer that the library can use for drawing + * + * @param width The width of the buffer + * @param height The height of the buffer + * @return Drawing buffer, which can be deallocated with (3), + * or `NULL` on failure + * + * @throws EINVAL `width` or `height` is zero + * @throws ENOMEM Cannot allocate enough memory + * + * @seealso rtgrpblib_reset_raster + */ RTGRPBLIB_RASTER *rtgrpblib_create_raster(size_t width, size_t height); + +/** + * Reshape and clear a drawing buffer + * + * @param raster The buffer to reshape and clear + * @param width The new width of the buffer + * @param height The new height of the buffer + * @return 0 on success, -1 on failure + * + * @throws EINVAL `width` or `height` is zero + * @throws EINVAL The buffers new area size exceeds its original area size + */ int rtgrpblib_reset_raster(RTGRPBLIB_RASTER *raster, size_t width, size_t height); + +/** + * Reconfigure a drawing buffer with a new draftness value + * + * When drawing a curve, the size of each step the library + * takes will be proportional to the draftness value, but + * will also depend on other factors. Doubling the draftness + * value with halve (disregarind overheads) the time it takes + * to draw any given curve. + * + * @param raster The drawing buffer to reconfigure + * @param draftness The new draftness value, must be positive + */ void rtgrpblib_set_draftness(RTGRPBLIB_RASTER *raster, double draftness); + +/** + * Create an image of the drawings applied to a drawing buffer + * + * All drawn shapes must be closed + * + * Shapes that are drawn in the same angular direction add to + * each other, shapes that are drawn in opposite angular + * directions subtract from each other + * + * @param image Output buffer, need not be initialised, but + * shall have an allocation size of `rowsize` + * multiplied by the height of `raster` and + * by `sizeof(double)` + * @param rowsize The number of elements in `image` per row, + * must be at least the width of `raster` + * @param raster The drawing buffer + * + * @seealso rtgrpblib_reset_raster + */ void rtgrpblib_fill_shapes(double *restrict image, size_t rowsize, const RTGRPBLIB_RASTER *raster); + +/** + * Draw a line between two points + * + * @param raster The drawing buffer + * @param x1, y1 The starting point + * @param x2, y2 The end point + */ void rtgrpblib_draw_linear_bezier(RTGRPBLIB_RASTER *restrict raster, double x1, double y1, double x2, double y2); +/** + * Draw a quadratic bézier curve + * + * @param raster The drawing buffer + * @param x1, y1 The starting point + * @param x2, y2 The control point + * @param x3, y3 The end point + */ void rtgrpblib_draw_quadratic_bezier(RTGRPBLIB_RASTER *restrict raster, double x1, double y1, double x2, double y2, double x3, double y3); -void rtgrpblib_draw_cubic_bezier(RTGRPBLIB_RASTER *restrict raster, +/** + * Draw a cubic bézier curve + * + * @param raster The drawing buffer + * @param x1, y1 The starting point + * @param x2, y2 The first control point + * @param x3, y3 The second control point + * @param x4, y4 The end point + */ +void rtgrpblib_draw_cubic_bezier(RTGRPBLIB_RASTER *restrict raster, /* needed for OpenType */ double x1, double y1, double x2, double y2, double x3, double y3, double x4, double y4); -void rtgrpblib_draw_circular_arc(RTGRPBLIB_RASTER *restrict raster, +/** + * Draw a cricular arc + * + * @param raster The drawing buffer + * @param x0, y0 The midpoint of the ellipse + * @param semiwidth Half the width of the ellipse + * @param semiheight Half the height of the ellipse + * @param start The angular starting point of the arc, in radians + * @param end The angular end point of the arc, in radians + */ +void rtgrpblib_draw_circular_arc(RTGRPBLIB_RASTER *restrict raster, /* needed for outline stoking */ double x0, double y0, double semiwidth, double semiheight, double start, double end); -/* TODO add support for outlining */ - #endif |