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Diffstat (limited to 'src/3rdparty/harfbuzz-ng/src/hb-paint-extents.hh')
| -rw-r--r-- | src/3rdparty/harfbuzz-ng/src/hb-paint-extents.hh | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-paint-extents.hh b/src/3rdparty/harfbuzz-ng/src/hb-paint-extents.hh new file mode 100644 index 0000000000..f172bd42f9 --- /dev/null +++ b/src/3rdparty/harfbuzz-ng/src/hb-paint-extents.hh @@ -0,0 +1,293 @@ +/* + * Copyright © 2022 Behdad Esfahbod + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#ifndef HB_PAINT_EXTENTS_HH +#define HB_PAINT_EXTENTS_HH + +#include "hb.hh" +#include "hb-paint.h" + + +typedef struct hb_extents_t +{ + hb_extents_t () {} + hb_extents_t (float xmin, float ymin, float xmax, float ymax) : + xmin (xmin), ymin (ymin), xmax (xmax), ymax (ymax) {} + + bool is_empty () const { return xmin >= xmax || ymin >= ymax; } + bool is_void () const { return xmin > xmax; } + + void union_ (const hb_extents_t &o) + { + xmin = hb_min (xmin, o.xmin); + ymin = hb_min (ymin, o.ymin); + xmax = hb_max (xmax, o.xmax); + ymax = hb_max (ymax, o.ymax); + } + + void intersect (const hb_extents_t &o) + { + xmin = hb_max (xmin, o.xmin); + ymin = hb_max (ymin, o.ymin); + xmax = hb_min (xmax, o.xmax); + ymax = hb_min (ymax, o.ymax); + } + + void + add_point (float x, float y) + { + if (unlikely (is_void ())) + { + xmin = xmax = x; + ymin = ymax = y; + } + else + { + xmin = hb_min (xmin, x); + ymin = hb_min (ymin, y); + xmax = hb_max (xmax, x); + ymax = hb_max (ymax, y); + } + } + + float xmin = 0.f; + float ymin = 0.f; + float xmax = -1.f; + float ymax = -1.f; +} hb_extents_t; + +typedef struct hb_transform_t +{ + hb_transform_t () {} + hb_transform_t (float xx, float yx, + float xy, float yy, + float x0, float y0) : + xx (xx), yx (yx), xy (xy), yy (yy), x0 (x0), y0 (y0) {} + + void multiply (const hb_transform_t &o) + { + /* Copied from cairo, with "o" being "a" there and "this" being "b" there. */ + hb_transform_t r; + + r.xx = o.xx * xx + o.yx * xy; + r.yx = o.xx * yx + o.yx * yy; + + r.xy = o.xy * xx + o.yy * xy; + r.yy = o.xy * yx + o.yy * yy; + + r.x0 = o.x0 * xx + o.y0 * xy + x0; + r.y0 = o.x0 * yx + o.y0 * yy + y0; + + *this = r; + } + + void transform_distance (float &dx, float &dy) const + { + float new_x = xx * dx + xy * dy; + float new_y = yx * dx + yy * dy; + dx = new_x; + dy = new_y; + } + + void transform_point (float &x, float &y) const + { + transform_distance (x, y); + x += x0; + y += y0; + } + + void transform_extents (hb_extents_t &extents) const + { + float quad_x[4], quad_y[4]; + + quad_x[0] = extents.xmin; + quad_y[0] = extents.ymin; + quad_x[1] = extents.xmin; + quad_y[1] = extents.ymax; + quad_x[2] = extents.xmax; + quad_y[2] = extents.ymin; + quad_x[3] = extents.xmax; + quad_y[3] = extents.ymax; + + extents = hb_extents_t {}; + for (unsigned i = 0; i < 4; i++) + { + transform_point (quad_x[i], quad_y[i]); + extents.add_point (quad_x[i], quad_y[i]); + } + } + + float xx = 1.f; + float yx = 0.f; + float xy = 0.f; + float yy = 1.f; + float x0 = 0.f; + float y0 = 0.f; +} hb_transform_t; + +typedef struct hb_bounds_t +{ + enum status_t { + UNBOUNDED, + BOUNDED, + EMPTY, + }; + + hb_bounds_t (status_t status) : status (status) {} + hb_bounds_t (const hb_extents_t &extents) : + status (extents.is_empty () ? EMPTY : BOUNDED), extents (extents) {} + + void union_ (const hb_bounds_t &o) + { + if (o.status == UNBOUNDED) + status = UNBOUNDED; + else if (o.status == BOUNDED) + { + if (status == EMPTY) + *this = o; + else if (status == BOUNDED) + extents.union_ (o.extents); + } + } + + void intersect (const hb_bounds_t &o) + { + if (o.status == EMPTY) + status = EMPTY; + else if (o.status == BOUNDED) + { + if (status == UNBOUNDED) + *this = o; + else if (status == BOUNDED) + { + extents.intersect (o.extents); + if (extents.is_empty ()) + status = EMPTY; + } + } + } + + status_t status; + hb_extents_t extents; +} hb_bounds_t; + +typedef struct hb_paint_extents_context_t hb_paint_extents_context_t; + +struct hb_paint_extents_context_t +{ + hb_paint_extents_context_t () + { + transforms.push (hb_transform_t{}); + clips.push (hb_bounds_t{hb_bounds_t::UNBOUNDED}); + groups.push (hb_bounds_t{hb_bounds_t::EMPTY}); + } + + hb_extents_t get_extents () + { + return groups.tail().extents; + } + + bool is_bounded () + { + return groups.tail().status != hb_bounds_t::UNBOUNDED; + } + + void push_transform (const hb_transform_t &trans) + { + hb_transform_t t = transforms.tail (); + t.multiply (trans); + transforms.push (t); + } + + void pop_transform () + { + transforms.pop (); + } + + void push_clip (hb_extents_t extents) + { + /* Transform extents and push a new clip. */ + const hb_transform_t &t = transforms.tail (); + t.transform_extents (extents); + + clips.push (hb_bounds_t {extents}); + } + + void pop_clip () + { + clips.pop (); + } + + void push_group () + { + groups.push (hb_bounds_t {hb_bounds_t::EMPTY}); + } + + void pop_group (hb_paint_composite_mode_t mode) + { + const hb_bounds_t src_bounds = groups.pop (); + hb_bounds_t &backdrop_bounds = groups.tail (); + + // https://learn.microsoft.com/en-us/typography/opentype/spec/colr#format-32-paintcomposite + switch ((int) mode) + { + case HB_PAINT_COMPOSITE_MODE_CLEAR: + backdrop_bounds.status = hb_bounds_t::EMPTY; + break; + case HB_PAINT_COMPOSITE_MODE_SRC: + case HB_PAINT_COMPOSITE_MODE_SRC_OUT: + backdrop_bounds = src_bounds; + break; + case HB_PAINT_COMPOSITE_MODE_DEST: + case HB_PAINT_COMPOSITE_MODE_DEST_OUT: + break; + case HB_PAINT_COMPOSITE_MODE_SRC_IN: + case HB_PAINT_COMPOSITE_MODE_DEST_IN: + backdrop_bounds.intersect (src_bounds); + break; + default: + backdrop_bounds.union_ (src_bounds); + break; + } + } + + void paint () + { + const hb_bounds_t &clip = clips.tail (); + hb_bounds_t &group = groups.tail (); + + group.union_ (clip); + } + + protected: + hb_vector_t<hb_transform_t> transforms; + hb_vector_t<hb_bounds_t> clips; + hb_vector_t<hb_bounds_t> groups; +}; + +HB_INTERNAL hb_paint_funcs_t * +hb_paint_extents_get_funcs (); + + +#endif /* HB_PAINT_EXTENTS_HH */ |