NouVeL/ADVect/Graphics.h

#pragma once

#include <SDL.h>

#include <optional>
#include <bgfx/bgfx.h>

#include <ft2build.h>
#include FT_FREETYPE_H

#include <Common.h>
#include <Environment.h>

namespace ADVect::Graphics {
	bool Init(u16 width, u16 height);
	void Shutdown();

	enum MarkupStyle {
		TEXT_NONE = 0,
		TEXT_BOLD = 1 << 0,
		TEXT_ITALIC = 1 << 1,
		TEXT_UNDERLINE = 1 << 2,
		TEXT_STRIKETHROUGH = 1 << 3,
		TEXT_OVERLINE = 1 << 4
	};

	struct ImageTexture {
		i32 w, h, channels;
		u8* buffer;
		bgfx::TextureHandle tx;
	};
	ImageTexture* GetImageTextureFromFile(const std::string& file);

	struct Font {
		FT_Face face = nullptr;
		std::unordered_map<NVL::Char, std::tuple<std::optional<bgfx::TextureHandle>, u32, u32, i32, i32, i32, i32>> cache{};

		std::tuple<std::optional<bgfx::TextureHandle>, u32, u32, i32, i32, i32, i32>& get_char(NVL::Char c);
	};

	void DrawTexture(const bgfx::TextureHandle& tex, i32 pos_x, i32 pos_y, u32 w, u32 h, u64 state, const bgfx::ProgramHandle& pg);
	void DrawTextureImage(const bgfx::TextureHandle& tex, i32 pos_x, i32 pos_y, u32 w, u32 h);
	void DrawTextureImage(const ImageTexture& img, i32 pos_x, i32 pos_y);
	void DrawTextureImageAlpha(const ImageTexture& img, i32 pos_x, i32 pos_y, f32 alpha);
	void DrawTextureStencilAlpha(const bgfx::TextureHandle& tex, i32 pos_x, i32 pos_y, u32 w, u32 h);
	
	Font* ResolveStyleFlags(u32 style_flags);

	template <bool DoRender, bool Walk>
	void RenderGlyph(NVL::Char c, std::conditional_t<Walk, i32&, i32> pos_x, std::conditional_t<Walk, i32&, i32> pos_y, u32 col, u32 style_flags) {
		Font* f = ResolveStyleFlags(style_flags);

		auto& [tx, w, h, l, t, x, y] = f->get_char(c);

		pos_x += l;

		if (auto& buf = tx; DoRender && tx && w != 0) {
			DrawTextureStencilAlpha(*buf, pos_x, pos_y - (h - t), w, h);
		}

		pos_x += x >> 6;
		pos_y += y >> 6;
	}

	template <bool DoRender, bool Walk>
	void RenderString(const NVL::String& s, std::conditional_t<Walk, i32&, i32> pos_x, std::conditional_t<Walk, i32&, i32> pos_y, u32 col, u32 style_flags) {
		for (const auto& c : s) {
			RenderGlyph<DoRender, true>(c, pos_x, pos_y, col, style_flags);
		}
	}

	template <bool DoRender, bool Walk>
	void RenderString(NVL::String::const_iterator cbegin, NVL::String::const_iterator cend, std::conditional_t<Walk, i32&, i32> pos_x, std::conditional_t<Walk, i32&, i32> pos_y, u32 col, u32 style_flags) {
		while (cbegin < cend) {
			RenderGlyph<DoRender, true>(*cbegin++, pos_x, pos_y, col, style_flags);
		}
	}

	i32 RenderSubstringBox(const NVL::String& s, i32& pos_x, i32& pos_y, i32 reset_x, u32 w, u32 col, u32 style_flags = TEXT_NONE, size_t s_end = NVL::String::npos);
	void RenderSubstringMarkupBox(const NVL::Environment::MarkupString& ms, i32 pos_x, i32 pos_y, u32 w, u32 col, size_t end = NVL::String::npos);
}