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/*
* Copyright © 2026 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.
*
* Author(s): Behdad Esfahbod
*/
#ifndef HB_RASTER_PAINT_HH
#define HB_RASTER_PAINT_HH
#include "hb.hh"
#include "hb-raster-image.hh"
#include "hb-geometry.hh"
/* hb_raster_clip_t — alpha mask for clipping */
struct hb_raster_clip_t
{
hb_vector_t<uint8_t> alpha; /* A8 mask, same extents as root surface */
unsigned width = 0;
unsigned height = 0;
unsigned stride = 0;
/* Fast path: simple rectangle (no alpha buffer needed) */
bool is_rect = true;
int rect_x0 = 0, rect_y0 = 0;
int rect_x1 = 0, rect_y1 = 0;
/* Bounding box of non-zero alpha region (valid for both rect and mask) */
unsigned min_x = 0, min_y = 0;
unsigned max_x = 0, max_y = 0;
void init_full (unsigned w, unsigned h)
{
width = w;
height = h;
stride = (w + 3u) & ~3u;
is_rect = true;
rect_x0 = 0;
rect_y0 = 0;
rect_x1 = (int) w;
rect_y1 = (int) h;
min_x = 0;
min_y = 0;
max_x = w;
max_y = h;
}
void update_bounds_from_rect ()
{
min_x = (unsigned) hb_max (rect_x0, 0);
min_y = (unsigned) hb_max (rect_y0, 0);
max_x = (unsigned) hb_max (hb_min (rect_x1, (int) width), 0);
max_y = (unsigned) hb_max (hb_min (rect_y1, (int) height), 0);
}
uint8_t get_alpha (unsigned x, unsigned y) const
{
if (is_rect)
return ((int) x >= rect_x0 && (int) x < rect_x1 &&
(int) y >= rect_y0 && (int) y < rect_y1) ? 255 : 0;
if (x >= width || y >= height) return 0;
return alpha[y * stride + x];
}
};
/* hb_raster_paint_t — color glyph paint context */
struct hb_raster_paint_t
{
hb_object_header_t header;
/* Configuration */
hb_transform_t<> base_transform = {1, 0, 0, 1, 0, 0};
float x_scale_factor = 1.f;
float y_scale_factor = 1.f;
hb_raster_extents_t fixed_extents = {};
bool has_extents = false;
hb_color_t foreground = HB_COLOR (0, 0, 0, 255);
hb_map_t *custom_palette = nullptr;
/* SVG rendering state */
hb_codepoint_t svg_glyph = 0;
hb_font_t *svg_font = nullptr;
unsigned svg_palette = 0;
/* Stacks */
hb_vector_t<hb_transform_t<>> transform_stack;
hb_vector_t<hb_raster_clip_t> clip_stack;
hb_vector_t<hb_raster_clip_t> clip_cache;
hb_vector_t<hb_raster_image_t *> surface_stack;
/* Cached surface pool (freelist for reuse across push/pop group) */
hb_vector_t<hb_raster_image_t *> surface_cache;
hb_vector_t<hb_color_stop_t> scratch_color_stops;
/* Internal rasterizer for clip-to-glyph */
hb_raster_draw_t *clip_rdr = nullptr;
/* Helpers */
hb_raster_image_t *acquire_surface ()
{
hb_raster_image_t *img;
if (surface_cache.length)
img = surface_cache.pop ();
else
{
img = hb_raster_image_create_or_fail ();
if (unlikely (!img)) return nullptr;
}
if (unlikely (!img->configure (HB_RASTER_FORMAT_BGRA32, fixed_extents)))
{
hb_raster_image_destroy (img);
return nullptr;
}
img->clear ();
return img;
}
void release_surface (hb_raster_image_t *img)
{
surface_cache.push (img);
}
hb_raster_clip_t acquire_clip (unsigned w, unsigned h)
{
hb_raster_clip_t clip;
if (clip_cache.length)
clip = clip_cache.pop ();
clip.width = w;
clip.height = h;
clip.stride = (w + 3u) & ~3u;
clip.is_rect = false;
return clip;
}
void release_clip (hb_raster_clip_t &&clip)
{
if (clip.alpha.arrayZ)
clip_cache.push (std::move (clip));
}
void release_all_clips ()
{
while (clip_stack.length)
release_clip (clip_stack.pop ());
}
hb_raster_image_t *current_surface ()
{
return surface_stack.length ? surface_stack.tail () : nullptr;
}
hb_raster_clip_t ¤t_clip ()
{
return clip_stack.tail ();
}
hb_transform_t<> ¤t_transform ()
{
return transform_stack.tail ();
}
void apply_scale_factor (hb_transform_t<> &t) const
{
t.xx /= x_scale_factor;
t.xy /= x_scale_factor;
t.x0 /= x_scale_factor;
t.yx /= y_scale_factor;
t.yy /= y_scale_factor;
t.y0 /= y_scale_factor;
}
hb_transform_t<> current_effective_transform ()
{
hb_transform_t<> t = current_transform ();
apply_scale_factor (t);
return t;
}
};
#endif /* HB_RASTER_PAINT_HH */