[paint-extents] Start out

src/Makefile.sources

@@ -91,6 +91,7 @@ HB_BASE_sources = \
 	hb-ot-layout-gpos-table.hh \
 	hb-paint.cc \
 	hb-paint.hh \
+	hb-paint-extents.hh \
 	hb-ot-layout-gsub-table.hh \
 	OT/glyf/glyf.hh \
 	OT/glyf/glyf-helpers.hh \

src/hb-ft-colr.hh

@@ -27,6 +27,8 @@
 
 #include "hb.hh"
 
+#include "hb-paint-extents.hh"
+
 #include FT_COLOR_H
 
 #ifndef HB_NO_PAINT

src/hb-paint-extents.hh

@@ -0,0 +1,288 @@
+/*
+ * 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.hh"
+
+
+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;
+  }
+
+  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
+{
+  hb_bounds_t () {}
+  hb_bounds_t (const hb_glyph_extents_t &extents) :
+    bounded (true), extents (extents) {}
+
+  bool bounded = false;
+  hb_glyph_extents_t extents = {0, 0, 0, 0};
+} 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 ()
+  {
+    clips.push (hb_bounds_t{});
+    bounds.push (hb_bounds_t{});
+    transforms.push (hb_transform_t{});
+  }
+
+  void push_transform (const hb_transform_t &trans)
+  {
+    hb_transform_t r = transforms.tail ();
+    r.multiply (trans);
+    transforms.push (r);
+  }
+
+  void pop_transform ()
+  {
+    transforms.pop ();
+  }
+
+  void push_clip (const hb_glyph_extents_t &extents)
+  {
+    hb_bounds_t b {extents};
+    clips.push (b);
+  }
+
+  void pop_clip ()
+  {
+    clips.pop ();
+  }
+
+  void push_group ()
+  {
+    bounds.push (hb_bounds_t{});
+  }
+
+  hb_bounds_t pop_group ()
+  {
+    return bounds.pop ();
+  }
+
+  void add_extents (const hb_glyph_extents_t &extents)
+  {
+    // TODO
+
+    //hb_transform_t &r = transforms.tail ();
+  }
+
+  hb_vector_t<hb_bounds_t> clips;
+  hb_vector_t<hb_bounds_t> bounds;
+  hb_vector_t<hb_transform_t> transforms;
+};
+
+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;
+
+  // TODO
+}
+
+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)
+{
+  // TODO
+}
+
+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;
+
+  hb_bounds_t bounds = c->pop_group ();
+
+  // TODO
+}
+
+static void
+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 *extents,
+			      void *user_data HB_UNUSED)
+{
+  // TODO
+}
+
+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)
+{
+  // TODO
+}
+
+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)
+{
+  // TODO
+}
+
+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)
+{
+  // TODO
+}
+
+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)
+{
+  // TODO
+}
+
+static inline hb_paint_funcs_t *
+hb_paint_extents_get_funcs ()
+{
+  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);
+
+  return funcs;
+}
+
+#endif /* HB_PAINT_EXTENTS_HH */

src/meson.build

@@ -46,6 +46,7 @@ hb_base_sources = files(
   'hb-draw.hh',
   'hb-paint.cc',
   'hb-paint.hh',
+  'hb-paint-extents.hh',
   'hb-face.cc',
   'hb-face.hh',
   'hb-fallback-shape.cc',