initial commit, 4.5 stable

thirdparty/harfbuzz/src/hb-paint-extents.cc

@@ -0,0 +1,245 @@
+/*
+ * 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.
+ */
+
+#include "hb.hh"
+
+#ifndef HB_NO_PAINT
+
+#include "hb-paint-extents.hh"
+
+#include "hb-draw.hh"
+
+#include "hb-machinery.hh"
+
+
+/*
+ * This file implements bounds-extraction computation of COLRv1 fonts as described in:
+ *
+ * https://learn.microsoft.com/en-us/typography/opentype/spec/colr#glyph-metrics-and-boundedness
+ */
+
+static void
+hb_paint_extents_push_transform (hb_paint_funcs_t *funcs HB_UNUSED,
+				 void *paint_data,
+				 float xx, float yx,
+				 float xy, float yy,
+				 float dx, float dy,
+				 void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->push_transform (hb_transform_t<> {xx, yx, xy, yy, dx, dy});
+}
+
+static void
+hb_paint_extents_pop_transform (hb_paint_funcs_t *funcs HB_UNUSED,
+			        void *paint_data,
+				void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->pop_transform ();
+}
+
+static void
+hb_paint_extents_push_clip_glyph (hb_paint_funcs_t *funcs HB_UNUSED,
+				  void *paint_data,
+				  hb_codepoint_t glyph,
+				  hb_font_t *font,
+				  void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  hb_extents_t<> extents;
+  hb_draw_funcs_t *draw_extent_funcs = hb_draw_extents_get_funcs ();
+  hb_font_draw_glyph (font, glyph, draw_extent_funcs, &extents);
+  c->push_clip (extents);
+}
+
+static void
+hb_paint_extents_push_clip_rectangle (hb_paint_funcs_t *funcs HB_UNUSED,
+				      void *paint_data,
+				      float xmin, float ymin, float xmax, float ymax,
+				      void *user_data)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  hb_extents_t<> extents = {xmin, ymin, xmax, ymax};
+  c->push_clip (extents);
+}
+
+static void
+hb_paint_extents_pop_clip (hb_paint_funcs_t *funcs HB_UNUSED,
+			   void *paint_data,
+			   void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->pop_clip ();
+}
+
+static void
+hb_paint_extents_push_group (hb_paint_funcs_t *funcs HB_UNUSED,
+			     void *paint_data,
+			     void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->push_group ();
+}
+
+static void
+hb_paint_extents_pop_group (hb_paint_funcs_t *funcs HB_UNUSED,
+			    void *paint_data,
+			    hb_paint_composite_mode_t mode,
+			    void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->pop_group (mode);
+}
+
+static hb_bool_t
+hb_paint_extents_paint_image (hb_paint_funcs_t *funcs HB_UNUSED,
+			      void *paint_data,
+			      hb_blob_t *blob HB_UNUSED,
+			      unsigned int width HB_UNUSED,
+			      unsigned int height HB_UNUSED,
+			      hb_tag_t format HB_UNUSED,
+			      float slant HB_UNUSED,
+			      hb_glyph_extents_t *glyph_extents,
+			      void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  if (!glyph_extents)
+    return false; // Happens with SVG images.
+
+  hb_extents_t<> extents = {(float) glyph_extents->x_bearing,
+			    (float) glyph_extents->y_bearing + glyph_extents->height,
+			    (float) glyph_extents->x_bearing + glyph_extents->width,
+			    (float) glyph_extents->y_bearing};
+  c->push_clip (extents);
+  c->paint ();
+  c->pop_clip ();
+
+  return true;
+}
+
+static void
+hb_paint_extents_paint_color (hb_paint_funcs_t *funcs HB_UNUSED,
+			      void *paint_data,
+			      hb_bool_t use_foreground HB_UNUSED,
+			      hb_color_t color HB_UNUSED,
+			      void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->paint ();
+}
+
+static void
+hb_paint_extents_paint_linear_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
+				        void *paint_data,
+				        hb_color_line_t *color_line HB_UNUSED,
+				        float x0 HB_UNUSED, float y0 HB_UNUSED,
+				        float x1 HB_UNUSED, float y1 HB_UNUSED,
+				        float x2 HB_UNUSED, float y2 HB_UNUSED,
+				        void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->paint ();
+}
+
+static void
+hb_paint_extents_paint_radial_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
+				        void *paint_data,
+				        hb_color_line_t *color_line HB_UNUSED,
+				        float x0 HB_UNUSED, float y0 HB_UNUSED, float r0 HB_UNUSED,
+				        float x1 HB_UNUSED, float y1 HB_UNUSED, float r1 HB_UNUSED,
+				        void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->paint ();
+}
+
+static void
+hb_paint_extents_paint_sweep_gradient (hb_paint_funcs_t *funcs HB_UNUSED,
+				       void *paint_data,
+				       hb_color_line_t *color_line HB_UNUSED,
+				       float cx HB_UNUSED, float cy HB_UNUSED,
+				       float start_angle HB_UNUSED,
+				       float end_angle HB_UNUSED,
+				       void *user_data HB_UNUSED)
+{
+  hb_paint_extents_context_t *c = (hb_paint_extents_context_t *) paint_data;
+
+  c->paint ();
+}
+
+static inline void free_static_paint_extents_funcs ();
+
+static struct hb_paint_extents_funcs_lazy_loader_t : hb_paint_funcs_lazy_loader_t<hb_paint_extents_funcs_lazy_loader_t>
+{
+  static hb_paint_funcs_t *create ()
+  {
+    hb_paint_funcs_t *funcs = hb_paint_funcs_create ();
+
+    hb_paint_funcs_set_push_transform_func (funcs, hb_paint_extents_push_transform, nullptr, nullptr);
+    hb_paint_funcs_set_pop_transform_func (funcs, hb_paint_extents_pop_transform, nullptr, nullptr);
+    hb_paint_funcs_set_push_clip_glyph_func (funcs, hb_paint_extents_push_clip_glyph, nullptr, nullptr);
+    hb_paint_funcs_set_push_clip_rectangle_func (funcs, hb_paint_extents_push_clip_rectangle, nullptr, nullptr);
+    hb_paint_funcs_set_pop_clip_func (funcs, hb_paint_extents_pop_clip, nullptr, nullptr);
+    hb_paint_funcs_set_push_group_func (funcs, hb_paint_extents_push_group, nullptr, nullptr);
+    hb_paint_funcs_set_pop_group_func (funcs, hb_paint_extents_pop_group, nullptr, nullptr);
+    hb_paint_funcs_set_color_func (funcs, hb_paint_extents_paint_color, nullptr, nullptr);
+    hb_paint_funcs_set_image_func (funcs, hb_paint_extents_paint_image, nullptr, nullptr);
+    hb_paint_funcs_set_linear_gradient_func (funcs, hb_paint_extents_paint_linear_gradient, nullptr, nullptr);
+    hb_paint_funcs_set_radial_gradient_func (funcs, hb_paint_extents_paint_radial_gradient, nullptr, nullptr);
+    hb_paint_funcs_set_sweep_gradient_func (funcs, hb_paint_extents_paint_sweep_gradient, nullptr, nullptr);
+
+    hb_paint_funcs_make_immutable (funcs);
+
+    hb_atexit (free_static_paint_extents_funcs);
+
+    return funcs;
+  }
+} static_paint_extents_funcs;
+
+static inline
+void free_static_paint_extents_funcs ()
+{
+  static_paint_extents_funcs.free_instance ();
+}
+
+hb_paint_funcs_t *
+hb_paint_extents_get_funcs ()
+{
+  return static_paint_extents_funcs.get_unconst ();
+}
+
+
+#endif