/**
 *    Copyright (C) 2026 andromeda <andromeda@galaxious.de>
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
**/

module rfont;

const int MAX_GLYPHS = 256;
const int INIT_VERTS = 20 * MAX_GLYPHS;

typedef Texture = usz;
alias Surface = void*;

struct RenderData
{
	float* verts;
	float* tcoords;
	ushort* elements;
	Texture atlas;
	usz nverts;
	usz nelements;
}

alias RenderProcSize = fn usz();
alias RenderProcInitPtr = fn void(void*);
alias RenderProcCreateAtlas = fn Texture(void*, uint, uint);
alias RenderProcFreeAtlas = fn void(void*, Texture);
alias RenderProcBitmapToAtlas = fn void(void*, Texture, uint, uint, uint, char*, float, float, float*, float*);
alias RenderProcRender = fn void(void*, RenderData*);
alias RenderProcSetFramebuffer = fn void(void*, uint, uint);
alias RenderProcSetColor = fn void(void*, float, float, float, float);
alias RenderProcSetSurface = fn void(void*, Surface);
alias RenderProcFreePtr = fn void(void*);

struct RendererProc
{
	RenderProcSize size;
	RenderProcInitPtr init_ptr;
	RenderProcCreateAtlas create_atlas;
	RenderProcFreeAtlas free_atlas;
	RenderProcBitmapToAtlas bitmap_to_atlas;
	RenderProcRender render;
	RenderProcSetFramebuffer set_framebuffer;
	RenderProcSetColor set_color;
	RenderProcSetSurface set_surface;
	RenderProcFreePtr free_ptr;
}

struct Renderer
{
	void* ctx;
	RendererProc proc;
}

extern fn usz Renderer.size(&self) @cname("RFont_renderer_size");
extern fn Renderer* renderer_init(RendererProc) @cname("RFont_renderer_init");
extern fn void renderer_initPtr(RendererProc, void*, Renderer*) @cname("RFont_renderer_initPtr");
extern fn void Renderer.set_framebuffer(&self, uint, uint) @cname("RFont_renderer_set_framebuffer");
extern fn void Renderer.set_surface(&self, Surface) @cname("RFont_renderer_set_surface");
extern fn void Renderer.set_color(&self, float, float, float, float) @cname("RFont_renderer_set_color");
extern fn void Renderer.free(&self) @cname("RFont_renderer_free");
extern fn void Renderer.free_ptr(&self) @cname("RFont_renderer_freePtr");

struct Glyph
{
	uint codepoint;
	usz size;
	int x;
	int x2;
	int y;
	int y2;
	Font* font;
	int src;
	float w;
	float h;
	float x1;
	float y1;
	float advance;
}

typedef Src = void;

struct Font
{
	Src* src;
	float fheight;
	float descent;
	float num_of_long_hor_metrics;
	float space_adv;
	uint max_height;
	Glyph[MAX_GLYPHS] glyphs;
	usz glyph_len;
	Texture atlas;
	usz atlas_width;
	usz atlas_height;
	float atlas_x;
	float atlas_y;
	float[INIT_VERTS * 3] verts;
	float[INIT_VERTS * 2] tcoords;
	ushort[INIT_VERTS * 6] elements;
}

extern fn CChar* codepoint_to_utf8(uint) @cname("RFont_codepoint_to_utf8");
extern fn Font* Renderer.font_init(&self, ZString, uint, usz, usz) @cname("RFont_font_init");
extern fn Font* Renderer.font_init_ptr(&self, ZString, uint, usz, usz, Font*) @cname("RFont_font_init_ptr");
extern fn Font* Renderer.font_init_data(&self, char*, uint, usz, usz) @cname("RFont_font_init_data");
extern fn Font* Renderer.font_init_data_ptr(&self, char*, uint, usz, usz, Font*) @cname("RFont_font_init_data_ptr");
extern fn void Renderer.font_free(&self, Font*) @cname("RFont_font_free");
extern fn void Renderer.font_free_ptr(&self, Font*) @cname("RFont_font_free_ptr");

alias GlyphFallbackCallback = fn Glyph(Renderer*, Font*, uint, usz);

extern fn GlyphFallbackCallback set_glyph_fallback_callback(GlyphFallbackCallback) @cname("RFont_set_glyph_fallback_callback");
extern fn Glyph Renderer.add_char(&self, Font*, CChar, usz) @cname("RFont_font_add_char");
extern fn Glyph Renderer.add_codepoint(&self, Font*, uint, usz) @cname("RFont_font_add_codepoint");
extern fn Glyph Renderer.add_codepoint_ex(&self, Font*, uint, usz, char) @cname("RFont_font_add_codepoint_ex");
extern fn void Renderer.add_string(&self, Font*, ZString, usz*, usz) @cname("RFont_font_add_string");
extern fn void Renderer.add_string_len(&self, Font*, ZString, usz, usz*, usz) @cname("RFont_font_add_string_len");
extern fn void Renderer.area(&self, Font*, ZString, uint, uint*, uint*) @cname("RFont_text_area");
extern fn void Renderer.area_spacing(&self, Font*, ZString, float, uint, uint*, uint*) @cname("RFont_text_area_spacing");
extern fn void Renderer.area_len(&self, Font*, ZString, usz, uint, usz, float, uint*, uint*) @cname("RFont_text_area_len");
extern fn void Renderer.draw_text(&self, Font*, ZString, float, float, uint) @cname("RFont_draw_text");
extern fn void Renderer.draw_text_spacing(&self, Font*, ZString, float, float, uint, float) @cname("RFont_draw_text_spacing");
extern fn void Renderer.draw_text_len(&self, Font*, ZString, usz, float, float, uint, float) @cname("RFont_draw_text_len");