/*

 * Copyright © 2022 Matthias Clasen

 *

 *  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_HH

#define HB_PAINT_HH

#include "hb.hh"

#include "hb-face.hh"

#include "hb-font.hh"

#define HB_PAINT_FUNCS_IMPLEMENT_CALLBACKS \

  HB_PAINT_FUNC_IMPLEMENT (push_transform) \

  HB_PAINT_FUNC_IMPLEMENT (pop_transform) \

  HB_PAINT_FUNC_IMPLEMENT (push_clip_glyph) \

  HB_PAINT_FUNC_IMPLEMENT (push_clip_rectangle) \

  HB_PAINT_FUNC_IMPLEMENT (pop_clip) \

  HB_PAINT_FUNC_IMPLEMENT (color) \

  HB_PAINT_FUNC_IMPLEMENT (image) \

  HB_PAINT_FUNC_IMPLEMENT (linear_gradient) \

  HB_PAINT_FUNC_IMPLEMENT (radial_gradient) \

  HB_PAINT_FUNC_IMPLEMENT (sweep_gradient) \

  HB_PAINT_FUNC_IMPLEMENT (push_group) \

  HB_PAINT_FUNC_IMPLEMENT (pop_group) \

  HB_PAINT_FUNC_IMPLEMENT (custom_palette_color) \

  /* ^--- Add new callbacks here */

struct hb_paint_funcs_t

{

  hb_object_header_t header;

  struct {

#define HB_PAINT_FUNC_IMPLEMENT(name) hb_paint_##name##_func_t name;

    HB_PAINT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_PAINT_FUNC_IMPLEMENT

  } func;

  struct {

#define HB_PAINT_FUNC_IMPLEMENT(name) void *name;

    HB_PAINT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_PAINT_FUNC_IMPLEMENT

  } *user_data;

  struct {

#define HB_PAINT_FUNC_IMPLEMENT(name) hb_destroy_func_t name;

    HB_PAINT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_PAINT_FUNC_IMPLEMENT

  } *destroy;

  void push_transform (void *paint_data,

                       float xx, float yx,

                       float xy, float yy,

                       float dx, float dy)

  { func.push_transform (this, paint_data,

                         xx, yx, xy, yy, dx, dy,

                         !user_data ? nullptr : user_data->push_transform); }

  void pop_transform (void *paint_data)

  { func.pop_transform (this, paint_data,

                        !user_data ? nullptr : user_data->pop_transform); }

  void push_clip_glyph (void *paint_data,

                        hb_codepoint_t glyph,

                        hb_font_t *font)

  { func.push_clip_glyph (this, paint_data,

                          glyph,

                          font,

                          !user_data ? nullptr : user_data->push_clip_glyph); }

  void push_clip_rectangle (void *paint_data,

                           float xmin, float ymin, float xmax, float ymax)

  { func.push_clip_rectangle (this, paint_data,

                              xmin, ymin, xmax, ymax,

                              !user_data ? nullptr : user_data->push_clip_rectangle); }

  void pop_clip (void *paint_data)

  { func.pop_clip (this, paint_data,

                   !user_data ? nullptr : user_data->pop_clip); }

  void color (void *paint_data,

              hb_bool_t is_foreground,

              hb_color_t color)

  { func.color (this, paint_data,

                is_foreground, color,

                !user_data ? nullptr : user_data->color); }

  bool image (void *paint_data,

              hb_blob_t *image,

              unsigned width, unsigned height,

              hb_tag_t format,

              float slant,

              hb_glyph_extents_t *extents)

  { return func.image (this, paint_data,

                       image, width, height, format, slant, extents,

                       !user_data ? nullptr : user_data->image); }

  void linear_gradient (void *paint_data,

                        hb_color_line_t *color_line,

                        float x0, float y0,

                        float x1, float y1,

                        float x2, float y2)

  { func.linear_gradient (this, paint_data,

                          color_line, x0, y0, x1, y1, x2, y2,

                          !user_data ? nullptr : user_data->linear_gradient); }

  void radial_gradient (void *paint_data,

                        hb_color_line_t *color_line,

                        float x0, float y0, float r0,

                        float x1, float y1, float r1)

  { func.radial_gradient (this, paint_data,

                          color_line, x0, y0, r0, x1, y1, r1,

                          !user_data ? nullptr : user_data->radial_gradient); }

  void sweep_gradient (void *paint_data,

                       hb_color_line_t *color_line,

                       float x0, float y0,

                       float start_angle,

                       float end_angle)

  { func.sweep_gradient (this, paint_data,

                         color_line, x0, y0, start_angle, end_angle,

                         !user_data ? nullptr : user_data->sweep_gradient); }

  void push_group (void *paint_data)

  { func.push_group (this, paint_data,

                     !user_data ? nullptr : user_data->push_group); }

  void pop_group (void *paint_data,

                  hb_paint_composite_mode_t mode)

  { func.pop_group (this, paint_data,

                    mode,

                    !user_data ? nullptr : user_data->pop_group); }

  bool custom_palette_color (void *paint_data,

                             unsigned int color_index,

                             hb_color_t *color)

  { return func.custom_palette_color (this, paint_data,

                                      color_index,

                                      color,

                                      !user_data ? nullptr : user_data->custom_palette_color); }

  /* Internal specializations. */

  void push_root_transform (void *paint_data,

                            const hb_font_t *font)

  {

    float upem = font->face->get_upem ();

    int xscale = font->x_scale, yscale = font->y_scale;

    float slant = font->slant_xy;

    push_transform (paint_data,

        xscale/upem, 0, slant * yscale/upem, yscale/upem, 0, 0);

  }

  void push_inverse_root_transform (void *paint_data,

                                    hb_font_t *font)

  {

    float upem = font->face->get_upem ();

    int xscale = font->x_scale ? font->x_scale : upem;

    int yscale = font->y_scale ? font->y_scale : upem;

    float slant = font->slant_xy;

    push_transform (paint_data,

        upem/xscale, 0, -slant * upem/xscale, upem/yscale, 0, 0);

  }

  HB_NODISCARD

  bool push_translate (void *paint_data,

                       float dx, float dy)

  {

    if (!dx && !dy)

      return false;

    push_transform (paint_data,

        1.f, 0.f, 0.f, 1.f, dx, dy);

    return true;

  }

  HB_NODISCARD

  bool push_scale (void *paint_data,

                   float sx, float sy)

  {

    if (sx == 1.f && sy == 1.f)

      return false;

    push_transform (paint_data,

        sx, 0.f, 0.f, sy, 0.f, 0.f);

    return true;

  }

  HB_NODISCARD

  bool push_rotate (void *paint_data,

                    float a)

  {

    if (!a)

      return false;

    float cc = cosf (a * (float) M_PI);

    float ss = sinf (a * (float) M_PI);

    push_transform (paint_data, cc, ss, -ss, cc, 0.f, 0.f);

    return true;

  }

  HB_NODISCARD

  bool push_skew (void *paint_data,

                  float sx, float sy)

  {

    if (!sx && !sy)

      return false;

    float x = tanf (-sx * (float) M_PI);

    float y = tanf (+sy * (float) M_PI);

    push_transform (paint_data, 1.f, y, x, 1.f, 0.f, 0.f);

    return true;

  }

};

DECLARE_NULL_INSTANCE (hb_paint_funcs_t);

#endif /* HB_PAINT_HH */