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Diffstat (limited to 'app/core/gimpscanconvert.c')
| -rw-r--r-- | app/core/gimpscanconvert.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/app/core/gimpscanconvert.c b/app/core/gimpscanconvert.c new file mode 100644 index 0000000..dc763bc --- /dev/null +++ b/app/core/gimpscanconvert.c @@ -0,0 +1,637 @@ +/* GIMP - The GNU Image Manipulation Program + * Copyright (C) 1995-1999 Spencer Kimball and Peter Mattis + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include "config.h" + +#include <string.h> + +#include <gdk-pixbuf/gdk-pixbuf.h> +#include <gegl.h> + +#include <cairo.h> + +#include "libgimpbase/gimpbase.h" +#include "libgimpmath/gimpmath.h" + +#include "core-types.h" + +#include "gimpboundary.h" +#include "gimpbezierdesc.h" +#include "gimpscanconvert.h" + + +struct _GimpScanConvert +{ + gdouble ratio_xy; + + gboolean clip; + gint clip_x; + gint clip_y; + gint clip_w; + gint clip_h; + + /* stroking options */ + gboolean do_stroke; + gdouble width; + GimpJoinStyle join; + GimpCapStyle cap; + gdouble miter; + gdouble dash_offset; + GArray *dash_info; + + GArray *path_data; +}; + + +/* public functions */ + +/** + * gimp_scan_convert_new: + * + * Create a new scan conversion context. + * + * Return value: a newly allocated #GimpScanConvert context. + */ +GimpScanConvert * +gimp_scan_convert_new (void) +{ + GimpScanConvert *sc = g_slice_new0 (GimpScanConvert); + + sc->path_data = g_array_new (FALSE, FALSE, sizeof (cairo_path_data_t)); + sc->ratio_xy = 1.0; + + return sc; +} + +GimpScanConvert * +gimp_scan_convert_new_from_boundary (const GimpBoundSeg *bound_segs, + gint n_bound_segs, + gint offset_x, + gint offset_y) +{ + g_return_val_if_fail (bound_segs == NULL || n_bound_segs != 0, NULL); + + if (bound_segs) + { + GimpBoundSeg *stroke_segs; + gint n_stroke_segs; + + stroke_segs = gimp_boundary_sort (bound_segs, n_bound_segs, + &n_stroke_segs); + + if (stroke_segs) + { + GimpBezierDesc *bezier; + + bezier = gimp_bezier_desc_new_from_bound_segs (stroke_segs, + n_bound_segs, + n_stroke_segs); + + g_free (stroke_segs); + + if (bezier) + { + GimpScanConvert *scan_convert; + + scan_convert = gimp_scan_convert_new (); + + gimp_bezier_desc_translate (bezier, offset_x, offset_y); + gimp_scan_convert_add_bezier (scan_convert, bezier); + + gimp_bezier_desc_free (bezier); + + return scan_convert; + } + } + } + + return NULL; +} + +/** + * gimp_scan_convert_free: + * @sc: a #GimpScanConvert context + * + * Frees the resources allocated for @sc. + */ +void +gimp_scan_convert_free (GimpScanConvert *sc) +{ + g_return_if_fail (sc != NULL); + + if (sc->path_data) + g_array_free (sc->path_data, TRUE); + + if (sc->dash_info) + g_array_free (sc->dash_info, TRUE); + + g_slice_free (GimpScanConvert, sc); +} + +/** + * gimp_scan_convert_set_pixel_ratio: + * @sc: a #GimpScanConvert context + * @ratio_xy: the aspect ratio of the major coordinate axes + * + * Sets the pixel aspect ratio. + */ +void +gimp_scan_convert_set_pixel_ratio (GimpScanConvert *sc, + gdouble ratio_xy) +{ + g_return_if_fail (sc != NULL); + + /* we only need the relative resolution */ + sc->ratio_xy = ratio_xy; +} + +/** + * gimp_scan_convert_set_clip_rectangle + * @sc: a #GimpScanConvert context + * @x: horizontal offset of clip rectangle + * @y: vertical offset of clip rectangle + * @width: width of clip rectangle + * @height: height of clip rectangle + * + * Sets a clip rectangle on @sc. Subsequent render operations will be + * restricted to this area. + */ +void +gimp_scan_convert_set_clip_rectangle (GimpScanConvert *sc, + gint x, + gint y, + gint width, + gint height) +{ + g_return_if_fail (sc != NULL); + + sc->clip = TRUE; + sc->clip_x = x; + sc->clip_y = y; + sc->clip_w = width; + sc->clip_h = height; +} + +/** + * gimp_scan_convert_add_polyline: + * @sc: a #GimpScanConvert context + * @n_points: number of points to add + * @points: array of points to add + * @closed: whether to close the polyline and make it a polygon + * + * Add a polyline with @n_points @points that may be open or closed. + * + * Please note that you should use gimp_scan_convert_stroke() if you + * specify open polygons. + */ +void +gimp_scan_convert_add_polyline (GimpScanConvert *sc, + guint n_points, + const GimpVector2 *points, + gboolean closed) +{ + GimpVector2 prev = { 0.0, 0.0, }; + cairo_path_data_t pd; + gint i; + + g_return_if_fail (sc != NULL); + g_return_if_fail (points != NULL); + g_return_if_fail (n_points > 0); + + for (i = 0; i < n_points; i++) + { + /* compress multiple identical coordinates */ + if (i == 0 || + prev.x != points[i].x || + prev.y != points[i].y) + { + pd.header.type = (i == 0) ? CAIRO_PATH_MOVE_TO : CAIRO_PATH_LINE_TO; + pd.header.length = 2; + sc->path_data = g_array_append_val (sc->path_data, pd); + + pd.point.x = points[i].x; + pd.point.y = points[i].y; + sc->path_data = g_array_append_val (sc->path_data, pd); + prev = points[i]; + } + } + + /* close the polyline when needed */ + if (closed) + { + pd.header.type = CAIRO_PATH_CLOSE_PATH; + pd.header.length = 1; + sc->path_data = g_array_append_val (sc->path_data, pd); + } +} + +/** + * gimp_scan_convert_add_polyline: + * @sc: a #GimpScanConvert context + * @bezier: a #GimpBezierDesc + * + * Adds a @bezier path to @sc. + * + * Please note that you should use gimp_scan_convert_stroke() if you + * specify open paths. + **/ +void +gimp_scan_convert_add_bezier (GimpScanConvert *sc, + const GimpBezierDesc *bezier) +{ + g_return_if_fail (sc != NULL); + g_return_if_fail (bezier != NULL); + + sc->path_data = g_array_append_vals (sc->path_data, + bezier->data, bezier->num_data); +} + +/** + * gimp_scan_convert_stroke: + * @sc: a #GimpScanConvert context + * @width: line width in pixels + * @join: how lines should be joined + * @cap: how to render the end of lines + * @miter: convert a mitered join to a bevelled join if the miter would + * extend to a distance of more than @miter times @width from + * the actual join point + * @dash_offset: offset to apply on the dash pattern + * @dash_info: dash pattern or %NULL for a solid line + * + * Stroke the content of a GimpScanConvert. The next + * gimp_scan_convert_render() will result in the outline of the + * polygon defined with the commands above. + * + * You cannot add additional polygons after this command. + * + * Note that if you have nonstandard resolution, "width" gives the + * width (in pixels) for a vertical stroke, i.e. use the X resolution + * to calculate the width of a stroke when operating with real world + * units. + */ +void +gimp_scan_convert_stroke (GimpScanConvert *sc, + gdouble width, + GimpJoinStyle join, + GimpCapStyle cap, + gdouble miter, + gdouble dash_offset, + GArray *dash_info) +{ + sc->do_stroke = TRUE; + sc->width = width; + sc->join = join; + sc->cap = cap; + sc->miter = miter; + + if (sc->dash_info) + { + g_array_free (sc->dash_info, TRUE); + sc->dash_info = NULL; + } + + if (dash_info && dash_info->len >= 2) + { + gint n_dashes; + gdouble *dashes; + gint i; + + dash_offset = dash_offset * MAX (width, 1.0); + + n_dashes = dash_info->len; + dashes = g_new (gdouble, dash_info->len); + + for (i = 0; i < dash_info->len ; i++) + dashes[i] = MAX (width, 1.0) * g_array_index (dash_info, gdouble, i); + + /* correct 0.0 in the first element (starts with a gap) */ + + if (dashes[0] == 0.0) + { + gdouble first; + + first = dashes[1]; + + /* shift the pattern to really starts with a dash and + * use the offset to skip into it. + */ + for (i = 0; i < dash_info->len - 2; i++) + { + dashes[i] = dashes[i+2]; + dash_offset += dashes[i]; + } + + if (dash_info->len % 2 == 1) + { + dashes[dash_info->len - 2] = first; + n_dashes --; + } + else if (dash_info->len > 2) + { + dashes [dash_info->len - 3] += first; + n_dashes -= 2; + } + } + + /* correct odd number of dash specifiers */ + + if (n_dashes % 2 == 1) + { + gdouble last; + + last = dashes[n_dashes - 1]; + dashes[0] += last; + dash_offset += last; + n_dashes --; + } + + if (n_dashes >= 2) + { + sc->dash_info = g_array_sized_new (FALSE, FALSE, + sizeof (gdouble), n_dashes); + sc->dash_info = g_array_append_vals (sc->dash_info, dashes, n_dashes); + sc->dash_offset = dash_offset; + } + + g_free (dashes); + } +} + + +/** + * gimp_scan_convert_render: + * @sc: a #GimpScanConvert context + * @buffer: the #GeglBuffer to render to + * @off_x: horizontal offset into the @buffer + * @off_y: vertical offset into the @buffer + * @antialias: whether to apply antialiasiing + * + * This is a wrapper around gimp_scan_convert_render_full() that replaces the + * content of the @buffer with a rendered form of the path passed in. + * + * You cannot add additional polygons after this command. + */ +void +gimp_scan_convert_render (GimpScanConvert *sc, + GeglBuffer *buffer, + gint off_x, + gint off_y, + gboolean antialias) +{ + gimp_scan_convert_render_full (sc, buffer, off_x, off_y, + TRUE, antialias, 1.0); +} + +/** + * gimp_scan_convert_render_value: + * @sc: a #GimpScanConvert context + * @buffer: the #GeglBuffer to render to + * @off_x: horizontal offset into the @buffer + * @off_y: vertical offset into the @buffer + * @value: value to use for covered pixels + * + * This is a wrapper around gimp_scan_convert_render_full() that + * doesn't do antialiasing but gives control over the value that + * should be used for pixels covered by the scan conversion. Uncovered + * pixels are set to zero. + * + * You cannot add additional polygons after this command. + */ +void +gimp_scan_convert_render_value (GimpScanConvert *sc, + GeglBuffer *buffer, + gint off_x, + gint off_y, + gdouble value) +{ + gimp_scan_convert_render_full (sc, buffer, off_x, off_y, + TRUE, FALSE, value); +} + +/** + * gimp_scan_convert_compose: + * @sc: a #GimpScanConvert context + * @buffer: the #GeglBuffer to render to + * @off_x: horizontal offset into the @buffer + * @off_y: vertical offset into the @buffer + * + * This is a wrapper around of gimp_scan_convert_render_full() that composes + * the (aliased) scan conversion on top of the content of the @buffer. + * + * You cannot add additional polygons after this command. + */ +void +gimp_scan_convert_compose (GimpScanConvert *sc, + GeglBuffer *buffer, + gint off_x, + gint off_y) +{ + gimp_scan_convert_render_full (sc, buffer, off_x, off_y, + FALSE, FALSE, 1.0); +} + +/** + * gimp_scan_convert_compose_value: + * @sc: a #GimpScanConvert context + * @buffer: the #GeglBuffer to render to + * @off_x: horizontal offset into the @buffer + * @off_y: vertical offset into the @buffer + * @value: value to use for covered pixels + * + * This is a wrapper around gimp_scan_convert_render_full() that + * composes the (aliased) scan conversion with value @value on top of the + * content of the @buffer. + * + * You cannot add additional polygons after this command. + */ +void +gimp_scan_convert_compose_value (GimpScanConvert *sc, + GeglBuffer *buffer, + gint off_x, + gint off_y, + gdouble value) +{ + gimp_scan_convert_render_full (sc, buffer, off_x, off_y, + FALSE, FALSE, value); +} + +/** + * gimp_scan_convert_render_full: + * @sc: a #GimpScanConvert context + * @buffer: the #GeglBuffer to render to + * @off_x: horizontal offset into the @buffer + * @off_y: vertical offset into the @buffer + * @replace: if true the original content of the @buffer gets estroyed + * @antialias: if true the rendering happens antialiased + * @value: value to use for covered pixels + * + * This function renders the area described by the path to the + * @buffer, taking the offset @off_x and @off_y in the buffer into + * account. The rendering can happen antialiased and be rendered on + * top of existing content or replacing it completely. The @value + * specifies the opacity value to be used for the objects in the @sc. + * + * You cannot add additional polygons after this command. + */ +void +gimp_scan_convert_render_full (GimpScanConvert *sc, + GeglBuffer *buffer, + gint off_x, + gint off_y, + gboolean replace, + gboolean antialias, + gdouble value) +{ + const Babl *format; + GeglBufferIterator *iter; + GeglRectangle *roi; + cairo_t *cr; + cairo_surface_t *surface; + cairo_path_t path; + gint bpp; + gint x, y; + gint width, height; + + g_return_if_fail (sc != NULL); + g_return_if_fail (GEGL_IS_BUFFER (buffer)); + + x = gegl_buffer_get_x (buffer); + y = gegl_buffer_get_y (buffer); + width = gegl_buffer_get_width (buffer); + height = gegl_buffer_get_height (buffer); + + if (sc->clip && ! gimp_rectangle_intersect (x, y, width, height, + sc->clip_x, sc->clip_y, + sc->clip_w, sc->clip_h, + &x, &y, &width, &height)) + return; + + path.status = CAIRO_STATUS_SUCCESS; + path.data = (cairo_path_data_t *) sc->path_data->data; + path.num_data = sc->path_data->len; + + format = babl_format ("Y u8"); + bpp = babl_format_get_bytes_per_pixel (format); + + iter = gegl_buffer_iterator_new (buffer, NULL, 0, format, + GEGL_ACCESS_READWRITE, GEGL_ABYSS_NONE, 1); + roi = &iter->items[0].roi; + + while (gegl_buffer_iterator_next (iter)) + { + guchar *data = iter->items[0].data; + guchar *tmp_buf = NULL; + const gint stride = cairo_format_stride_for_width (CAIRO_FORMAT_A8, + roi->width); + + /* cairo rowstrides are always multiples of 4, whereas + * maskPR.rowstride can be anything, so to be able to create an + * image surface, we maybe have to create our own temporary + * buffer + */ + if (roi->width * bpp != stride) + { + tmp_buf = g_alloca (stride * roi->height); + + if (! replace) + { + const guchar *src = data; + guchar *dest = tmp_buf; + gint i; + + for (i = 0; i < roi->height; i++) + { + memcpy (dest, src, roi->width * bpp); + + src += roi->width * bpp; + dest += stride; + } + } + } + + surface = cairo_image_surface_create_for_data (tmp_buf ? + tmp_buf : data, + CAIRO_FORMAT_A8, + roi->width, roi->height, + stride); + + cairo_surface_set_device_offset (surface, + -off_x - roi->x, + -off_y - roi->y); + cr = cairo_create (surface); + cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE); + + if (replace) + { + cairo_set_source_rgba (cr, 0, 0, 0, 0); + cairo_paint (cr); + } + + cairo_set_source_rgba (cr, 0, 0, 0, value); + cairo_append_path (cr, &path); + + cairo_set_antialias (cr, antialias ? + CAIRO_ANTIALIAS_GRAY : CAIRO_ANTIALIAS_NONE); + cairo_set_miter_limit (cr, sc->miter); + + if (sc->do_stroke) + { + cairo_set_line_cap (cr, + sc->cap == GIMP_CAP_BUTT ? CAIRO_LINE_CAP_BUTT : + sc->cap == GIMP_CAP_ROUND ? CAIRO_LINE_CAP_ROUND : + CAIRO_LINE_CAP_SQUARE); + cairo_set_line_join (cr, + sc->join == GIMP_JOIN_MITER ? CAIRO_LINE_JOIN_MITER : + sc->join == GIMP_JOIN_ROUND ? CAIRO_LINE_JOIN_ROUND : + CAIRO_LINE_JOIN_BEVEL); + + cairo_set_line_width (cr, sc->width); + + if (sc->dash_info) + cairo_set_dash (cr, + (double *) sc->dash_info->data, + sc->dash_info->len, + sc->dash_offset); + + cairo_scale (cr, 1.0, sc->ratio_xy); + cairo_stroke (cr); + } + else + { + cairo_set_fill_rule (cr, CAIRO_FILL_RULE_EVEN_ODD); + cairo_fill (cr); + } + + cairo_destroy (cr); + cairo_surface_destroy (surface); + + if (tmp_buf) + { + const guchar *src = tmp_buf; + guchar *dest = data; + gint i; + + for (i = 0; i < roi->height; i++) + { + memcpy (dest, src, roi->width * bpp); + + src += stride; + dest += roi->width * bpp; + } + } + } +} |