/* SPDX-License-Identifier: MIT */
/*
 * konfont.h
 *
 * Copyright (c) 2026 KonAki
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef KONFONT_H
#define KONFONT_H

#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>

#include "konsofren.h"

#define KON_FONT_FIRST_CHAR 32
#define KON_FONT_NUM_CHARS 95

typedef struct kon_font kon_font_t;

/*** font declarations ***/

kon_font_t *kon_loadFont(const uint8_t *ttf_data, size_t size, float pixelHeight);

/* a small built in 8x13 bitmap font, needs no files. scale 1 is 13 pixels high, 2 is 26 and so on.
   monospace, ascii only, the baseline is 10 rows below the top. kon_fontGetAtlas gives NULL for it */
kon_font_t *kon_loadBuiltinFont(int scale);
void kon_freeFont(kon_font_t *font);

kon_image *kon_fontGetAtlas(kon_font_t *font);

/* the ttf data has to stay alive for as long as the font, resizing bakes from it again */
float kon_fontPixelHeight(const kon_font_t *font);
int kon_fontResize(kon_font_t *font, float pixelHeight);

/*** text draw declarations ***/

void kon_drawText(kon_framebuffer_t *fb, kon_font_t *font, int x, int y, const char *text, uint32_t color);
void kon_measureText(kon_font_t *font, const char *text, int *outWidth, int *outHeight);

/*** implementatoin ***/

#ifdef KONFONT_IMPLEMENTATION

#include "stb_truetype.h"

struct kon_font {
	int builtin, scale;
	const uint8_t *ttf;
	stbtt_bakedchar chardata[KON_FONT_NUM_CHARS];
	uint8_t *atlasPixels;
	int atlasSize;
	float pixelHeight;
};

/*** built in font ***/

/* 8x13 glyphs for ascii 32 to 126, one byte per row, leftmost pixel is the top bit. public domain misc-fixed derived font */
static const unsigned char kon_builtinGlyphs_[KON_FONT_NUM_CHARS][13] = {
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /*   */
	{ 0x00, 0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00, 0x10, 0x00, 0x00 }, /* ! */
	{ 0x00, 0x00, 0x24, 0x24, 0x24, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* " */
	{ 0x00, 0x00, 0x00, 0x24, 0x24, 0x7E, 0x24, 0x7E, 0x24, 0x24, 0x00, 0x00, 0x00 }, /* # */
	{ 0x00, 0x00, 0x10, 0x3C, 0x50, 0x50, 0x38, 0x14, 0x14, 0x78, 0x10, 0x00, 0x00 }, /* $ */
	{ 0x00, 0x00, 0x22, 0x52, 0x24, 0x08, 0x08, 0x10, 0x24, 0x2A, 0x44, 0x00, 0x00 }, /* % */
	{ 0x00, 0x00, 0x00, 0x00, 0x30, 0x48, 0x48, 0x30, 0x4A, 0x44, 0x3A, 0x00, 0x00 }, /* & */
	{ 0x00, 0x00, 0x10, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* ' */
	{ 0x00, 0x00, 0x04, 0x08, 0x08, 0x10, 0x10, 0x10, 0x08, 0x08, 0x04, 0x00, 0x00 }, /* ( */
	{ 0x00, 0x00, 0x20, 0x10, 0x10, 0x08, 0x08, 0x08, 0x10, 0x10, 0x20, 0x00, 0x00 }, /* ) */
	{ 0x00, 0x00, 0x00, 0x00, 0x24, 0x18, 0x7E, 0x18, 0x24, 0x00, 0x00, 0x00, 0x00 }, /* ch42 */
	{ 0x00, 0x00, 0x00, 0x00, 0x10, 0x10, 0x7C, 0x10, 0x10, 0x00, 0x00, 0x00, 0x00 }, /* + */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x38, 0x30, 0x40, 0x00 }, /* , */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x7C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* - */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x38, 0x10, 0x00 }, /* . */
	{ 0x00, 0x00, 0x02, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x80, 0x00, 0x00 }, /* ch47 */
	{ 0x00, 0x00, 0x18, 0x24, 0x42, 0x42, 0x42, 0x42, 0x42, 0x24, 0x18, 0x00, 0x00 }, /* 0 */
	{ 0x00, 0x00, 0x10, 0x30, 0x50, 0x10, 0x10, 0x10, 0x10, 0x10, 0x7C, 0x00, 0x00 }, /* 1 */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x02, 0x04, 0x18, 0x20, 0x40, 0x7E, 0x00, 0x00 }, /* 2 */
	{ 0x00, 0x00, 0x7E, 0x02, 0x04, 0x08, 0x1C, 0x02, 0x02, 0x42, 0x3C, 0x00, 0x00 }, /* 3 */
	{ 0x00, 0x00, 0x04, 0x0C, 0x14, 0x24, 0x44, 0x44, 0x7E, 0x04, 0x04, 0x00, 0x00 }, /* 4 */
	{ 0x00, 0x00, 0x7E, 0x40, 0x40, 0x5C, 0x62, 0x02, 0x02, 0x42, 0x3C, 0x00, 0x00 }, /* 5 */
	{ 0x00, 0x00, 0x1C, 0x20, 0x40, 0x40, 0x5C, 0x62, 0x42, 0x42, 0x3C, 0x00, 0x00 }, /* 6 */
	{ 0x00, 0x00, 0x7E, 0x02, 0x04, 0x08, 0x08, 0x10, 0x10, 0x20, 0x20, 0x00, 0x00 }, /* 7 */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x42, 0x3C, 0x42, 0x42, 0x42, 0x3C, 0x00, 0x00 }, /* 8 */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x46, 0x3A, 0x02, 0x02, 0x04, 0x38, 0x00, 0x00 }, /* 9 */
	{ 0x00, 0x00, 0x00, 0x00, 0x10, 0x38, 0x10, 0x00, 0x00, 0x10, 0x38, 0x10, 0x00 }, /* : */
	{ 0x00, 0x00, 0x00, 0x00, 0x10, 0x38, 0x10, 0x00, 0x00, 0x38, 0x30, 0x40, 0x00 }, /* ; */
	{ 0x00, 0x00, 0x02, 0x04, 0x08, 0x10, 0x20, 0x10, 0x08, 0x04, 0x02, 0x00, 0x00 }, /* < */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x7E, 0x00, 0x00, 0x00, 0x00 }, /* = */
	{ 0x00, 0x00, 0x40, 0x20, 0x10, 0x08, 0x04, 0x08, 0x10, 0x20, 0x40, 0x00, 0x00 }, /* > */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x02, 0x04, 0x08, 0x08, 0x00, 0x08, 0x00, 0x00 }, /* ? */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x4E, 0x52, 0x56, 0x4A, 0x40, 0x3C, 0x00, 0x00 }, /* @ */
	{ 0x00, 0x00, 0x18, 0x24, 0x42, 0x42, 0x42, 0x7E, 0x42, 0x42, 0x42, 0x00, 0x00 }, /* A */
	{ 0x00, 0x00, 0x78, 0x44, 0x42, 0x44, 0x78, 0x44, 0x42, 0x44, 0x78, 0x00, 0x00 }, /* B */
	{ 0x00, 0x00, 0x3C, 0x42, 0x40, 0x40, 0x40, 0x40, 0x40, 0x42, 0x3C, 0x00, 0x00 }, /* C */
	{ 0x00, 0x00, 0x78, 0x44, 0x42, 0x42, 0x42, 0x42, 0x42, 0x44, 0x78, 0x00, 0x00 }, /* D */
	{ 0x00, 0x00, 0x7E, 0x40, 0x40, 0x40, 0x78, 0x40, 0x40, 0x40, 0x7E, 0x00, 0x00 }, /* E */
	{ 0x00, 0x00, 0x7E, 0x40, 0x40, 0x40, 0x78, 0x40, 0x40, 0x40, 0x40, 0x00, 0x00 }, /* F */
	{ 0x00, 0x00, 0x3C, 0x42, 0x40, 0x40, 0x40, 0x4E, 0x42, 0x46, 0x3A, 0x00, 0x00 }, /* G */
	{ 0x00, 0x00, 0x42, 0x42, 0x42, 0x42, 0x7E, 0x42, 0x42, 0x42, 0x42, 0x00, 0x00 }, /* H */
	{ 0x00, 0x00, 0x7C, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x7C, 0x00, 0x00 }, /* I */
	{ 0x00, 0x00, 0x1F, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x44, 0x38, 0x00, 0x00 }, /* J */
	{ 0x00, 0x00, 0x42, 0x44, 0x48, 0x50, 0x60, 0x50, 0x48, 0x44, 0x42, 0x00, 0x00 }, /* K */
	{ 0x00, 0x00, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x7E, 0x00, 0x00 }, /* L */
	{ 0x00, 0x00, 0x82, 0x82, 0xC6, 0xAA, 0x92, 0x92, 0x82, 0x82, 0x82, 0x00, 0x00 }, /* M */
	{ 0x00, 0x00, 0x42, 0x42, 0x62, 0x52, 0x4A, 0x46, 0x42, 0x42, 0x42, 0x00, 0x00 }, /* N */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x3C, 0x00, 0x00 }, /* O */
	{ 0x00, 0x00, 0x7C, 0x42, 0x42, 0x42, 0x7C, 0x40, 0x40, 0x40, 0x40, 0x00, 0x00 }, /* P */
	{ 0x00, 0x00, 0x3C, 0x42, 0x42, 0x42, 0x42, 0x42, 0x52, 0x4A, 0x3C, 0x02, 0x00 }, /* Q */
	{ 0x00, 0x00, 0x7C, 0x42, 0x42, 0x42, 0x7C, 0x50, 0x48, 0x44, 0x42, 0x00, 0x00 }, /* R */
	{ 0x00, 0x00, 0x3C, 0x42, 0x40, 0x40, 0x3C, 0x02, 0x02, 0x42, 0x3C, 0x00, 0x00 }, /* S */
	{ 0x00, 0x00, 0xFE, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00, 0x00 }, /* T */
	{ 0x00, 0x00, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x42, 0x3C, 0x00, 0x00 }, /* U */
	{ 0x00, 0x00, 0x82, 0x82, 0x44, 0x44, 0x44, 0x28, 0x28, 0x28, 0x10, 0x00, 0x00 }, /* V */
	{ 0x00, 0x00, 0x82, 0x82, 0x82, 0x82, 0x92, 0x92, 0x92, 0xAA, 0x44, 0x00, 0x00 }, /* W */
	{ 0x00, 0x00, 0x82, 0x82, 0x44, 0x28, 0x10, 0x28, 0x44, 0x82, 0x82, 0x00, 0x00 }, /* X */
	{ 0x00, 0x00, 0x82, 0x82, 0x44, 0x28, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00, 0x00 }, /* Y */
	{ 0x00, 0x00, 0x7E, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x40, 0x7E, 0x00, 0x00 }, /* Z */
	{ 0x00, 0x00, 0x3C, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x3C, 0x00, 0x00 }, /* [ */
	{ 0x00, 0x00, 0x80, 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x02, 0x00, 0x00 }, /* ch92 */
	{ 0x00, 0x00, 0x78, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x78, 0x00, 0x00 }, /* ] */
	{ 0x00, 0x00, 0x10, 0x28, 0x44, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* ^ */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFE, 0x00 }, /* _ */
	{ 0x00, 0x10, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* ` */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x02, 0x3E, 0x42, 0x46, 0x3A, 0x00, 0x00 }, /* a */
	{ 0x00, 0x00, 0x40, 0x40, 0x40, 0x5C, 0x62, 0x42, 0x42, 0x62, 0x5C, 0x00, 0x00 }, /* b */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x42, 0x40, 0x40, 0x42, 0x3C, 0x00, 0x00 }, /* c */
	{ 0x00, 0x00, 0x02, 0x02, 0x02, 0x3A, 0x46, 0x42, 0x42, 0x46, 0x3A, 0x00, 0x00 }, /* d */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x42, 0x7E, 0x40, 0x42, 0x3C, 0x00, 0x00 }, /* e */
	{ 0x00, 0x00, 0x1C, 0x22, 0x20, 0x20, 0x7C, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00 }, /* f */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3A, 0x44, 0x44, 0x38, 0x40, 0x3C, 0x42, 0x3C }, /* g */
	{ 0x00, 0x00, 0x40, 0x40, 0x40, 0x5C, 0x62, 0x42, 0x42, 0x42, 0x42, 0x00, 0x00 }, /* h */
	{ 0x00, 0x00, 0x00, 0x10, 0x00, 0x30, 0x10, 0x10, 0x10, 0x10, 0x7C, 0x00, 0x00 }, /* i */
	{ 0x00, 0x00, 0x00, 0x04, 0x00, 0x0C, 0x04, 0x04, 0x04, 0x04, 0x44, 0x44, 0x38 }, /* j */
	{ 0x00, 0x00, 0x40, 0x40, 0x40, 0x44, 0x48, 0x70, 0x48, 0x44, 0x42, 0x00, 0x00 }, /* k */
	{ 0x00, 0x00, 0x30, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x7C, 0x00, 0x00 }, /* l */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x92, 0x92, 0x92, 0x92, 0x82, 0x00, 0x00 }, /* m */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x5C, 0x62, 0x42, 0x42, 0x42, 0x42, 0x00, 0x00 }, /* n */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x42, 0x42, 0x42, 0x42, 0x3C, 0x00, 0x00 }, /* o */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x5C, 0x62, 0x42, 0x62, 0x5C, 0x40, 0x40, 0x40 }, /* p */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3A, 0x46, 0x42, 0x46, 0x3A, 0x02, 0x02, 0x02 }, /* q */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x5C, 0x22, 0x20, 0x20, 0x20, 0x20, 0x00, 0x00 }, /* r */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x3C, 0x42, 0x30, 0x0C, 0x42, 0x3C, 0x00, 0x00 }, /* s */
	{ 0x00, 0x00, 0x00, 0x20, 0x20, 0x7C, 0x20, 0x20, 0x20, 0x22, 0x1C, 0x00, 0x00 }, /* t */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x44, 0x44, 0x44, 0x44, 0x44, 0x3A, 0x00, 0x00 }, /* u */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x44, 0x44, 0x44, 0x28, 0x28, 0x10, 0x00, 0x00 }, /* v */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x82, 0x82, 0x92, 0x92, 0xAA, 0x44, 0x00, 0x00 }, /* w */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x42, 0x24, 0x18, 0x18, 0x24, 0x42, 0x00, 0x00 }, /* x */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x42, 0x42, 0x42, 0x46, 0x3A, 0x02, 0x42, 0x3C }, /* y */
	{ 0x00, 0x00, 0x00, 0x00, 0x00, 0x7E, 0x04, 0x08, 0x10, 0x20, 0x7E, 0x00, 0x00 }, /* z */
	{ 0x00, 0x00, 0x0E, 0x10, 0x10, 0x08, 0x30, 0x08, 0x10, 0x10, 0x0E, 0x00, 0x00 }, /* { */
	{ 0x00, 0x00, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x00, 0x00 }, /* | */
	{ 0x00, 0x00, 0x70, 0x08, 0x08, 0x10, 0x0C, 0x10, 0x08, 0x08, 0x70, 0x00, 0x00 }, /* } */
	{ 0x00, 0x00, 0x24, 0x54, 0x48, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }, /* ~ */
};

#define KON_BUILTIN_WIDTH 8
#define KON_BUILTIN_HEIGHT 13
#define KON_BUILTIN_BASELINE 10
#define KON_BUILTIN_MAX_SCALE 8

static void kon_fontDrawBuiltin_(kon_framebuffer_t *fb, const kon_font_t *font, int x, int y, const char *text, uint32_t color) {
	int s = font->scale;
	int top = y - KON_BUILTIN_BASELINE * s;

	color = (color & 0x00FFFFFFu) | 0xFF000000u;

	for (const char *p = text; *p; p++) {
		unsigned char c = (unsigned char)*p;
		if (c < KON_FONT_FIRST_CHAR || c >= KON_FONT_FIRST_CHAR + KON_FONT_NUM_CHARS) continue;

		for (int row = 0; row < KON_BUILTIN_HEIGHT; row++) {
			unsigned char bits = kon_builtinGlyphs_[c - KON_FONT_FIRST_CHAR][row];

			for (int bit = 0; bit < KON_BUILTIN_WIDTH; ) {
				if (!(bits & (0x80 >> bit))) {
					bit++;
					continue;
				}
				int start = bit;
				while (bit < KON_BUILTIN_WIDTH && (bits & (0x80 >> bit))) bit++;
				kon_fillRectangle(fb, x + start * s, top + row * s, (bit - start) * s, s, color);
			}
		}
		x += KON_BUILTIN_WIDTH * s;
	}
}

kon_font_t *kon_loadBuiltinFont(int scale) {
	if (scale < 1 || scale > KON_BUILTIN_MAX_SCALE) return NULL;

	kon_font_t *font = calloc(1, sizeof(kon_font_t));
	if (!font) return NULL;

	font->builtin = 1;
	font->scale = scale;
	font->pixelHeight = (float)(KON_BUILTIN_HEIGHT * scale);
	return font;
}

/*** private helpers ***/

static bool kon_fontBakeAtlas(kon_font_t *font, const uint8_t *ttf_data, float pixelHeight) {
	int sizes[] = {256, 512, 1024, 2048};
	
	for (int i = 0; i < 4; i++) {
		int atlasSize = sizes[i];

		uint8_t *bitmap = malloc((size_t)atlasSize * (size_t)atlasSize);
		if (!bitmap) return false;

		int result = stbtt_BakeFontBitmap(ttf_data, 0, pixelHeight, bitmap, atlasSize, atlasSize, KON_FONT_FIRST_CHAR, KON_FONT_NUM_CHARS, font->chardata);

		if (result > 0) {
			font->atlasPixels = bitmap;
			font->atlasSize = atlasSize;
			return true;
		}

		free(bitmap);
	}

	return false;
}

/*** font implementation ***/

kon_font_t *kon_loadFont(const uint8_t *ttf_data, size_t size, float pixelHeight) {
	(void)size;

	if (!ttf_data || pixelHeight <= 0.0f) return NULL;

	kon_font_t *font = calloc(1, sizeof(kon_font_t));
	if (!font) return NULL;

	font->ttf = ttf_data;
	font->atlasPixels = NULL;
	font->pixelHeight = pixelHeight;

	if (!kon_fontBakeAtlas(font, ttf_data, pixelHeight)) {
		free(font);
		return NULL;
	}

	return font;
}

void kon_freeFont(kon_font_t *font) {
	if (!font) return;

	free(font->atlasPixels);
	free(font);
}

float kon_fontPixelHeight(const kon_font_t *font) {
	return font ? font->pixelHeight : 0.0f;
}

int kon_fontResize(kon_font_t *font, float pixelHeight) {
	kon_font_t next;

	if (!font || pixelHeight <= 0.0f) return 0;

	if (font->builtin) {
		int scale = (int)(pixelHeight / (float)KON_BUILTIN_HEIGHT + 0.5f);
		if (scale < 1) scale = 1;
		if (scale > KON_BUILTIN_MAX_SCALE) scale = KON_BUILTIN_MAX_SCALE;
		font->scale = scale;
		font->pixelHeight = (float)(KON_BUILTIN_HEIGHT * scale);
		return 1;
	}

	next = *font;
	next.atlasPixels = NULL;
	if (!kon_fontBakeAtlas(&next, font->ttf, pixelHeight)) return 0;

	free(font->atlasPixels);
	next.pixelHeight = pixelHeight;
	*font = next;
	return 1;
}

kon_image *kon_fontGetAtlas(kon_font_t *font) {
	if (!font || font->builtin) return NULL;

	int n = font->atlasSize * font->atlasSize;
	uint8_t *rgba = malloc((size_t)n * 4);
	if (!rgba) return NULL;

	for (int i = 0; i < n; i++) {
		uint8_t a = font->atlasPixels[i];
		rgba[i * 4 + 0] = 255;
		rgba[i * 4 + 1] = 255;
		rgba[i * 4 + 2] = 255;
		rgba[i * 4 + 3] = a;
	}

	kon_image *img = kon_loadImage(rgba, font->atlasSize, font->atlasSize, konFormatRGBA8);
	free(rgba);
	return img;
}

/*** text draw implementation ***/

void kon_drawText(kon_framebuffer_t *fb, kon_font_t *font, int x, int y, const char *text, uint32_t color) {
	if (!fb || !font || !text) return;

	if (font->builtin) {
		kon_fontDrawBuiltin_(fb, font, x, y, text, color);
		return;
	}

	uint32_t baseColor = color & 0x00FFFFFF;

	float cursorX = (float)x;
	float cursorY = (float)y;

	for (const char *p = text; *p; p++) {
		unsigned char c = (unsigned char)*p;

		if (c < KON_FONT_FIRST_CHAR || c >= KON_FONT_FIRST_CHAR + KON_FONT_NUM_CHARS) continue;

		stbtt_aligned_quad q;
		stbtt_GetBakedQuad(font->chardata, font->atlasSize, font->atlasSize, c - KON_FONT_FIRST_CHAR, &cursorX, &cursorY, &q, 0);

		int src_x0 = (int)(q.s0 * font->atlasSize);
		int src_y0 = (int)(q.t0 * font->atlasSize);
		int glyphW = (int)(q.x1 - q.x0);
		int glyphH = (int)(q.y1 - q.y0);

		int dstX = (int)q.x0;
		int dstY = (int)q.y0;
		int gx0 = 0, gy0 = 0;

		if (dstX < 0) gx0 = -dstX;
		if (dstY < 0) gy0 = -dstY;
		int gx1 = glyphW, gy1 = glyphH;
		if (dstX + gx1 > fb->width)  gx1 = fb->width  - dstX;
		if (dstY + gy1 > fb->height) gy1 = fb->height - dstY;

		for (int gy = gy0; gy < gy1; gy++) {
			const uint8_t *in = font->atlasPixels + (size_t)(src_y0 + gy) * font->atlasSize + src_x0;
			uint32_t *out = fb->data + (size_t)(dstY + gy) * fb->width + dstX;

			for (int gx = gx0; gx < gx1; gx++) {
				uint32_t alpha = in[gx];
				if (alpha == 0) continue;

				if (alpha == 0xFF) {
					out[gx] = 0xFF000000u | baseColor;
					continue;
				}

				uint32_t dst = out[gx];
				uint32_t inv = 255 - alpha;
				uint32_t r = (((baseColor >> 16) & 0xFF) * alpha + ((dst >> 16) & 0xFF) * inv) / 255;
				uint32_t g = (((baseColor >> 8)  & 0xFF) * alpha + ((dst >> 8)  & 0xFF) * inv) / 255;
				uint32_t b = ((baseColor & 0xFF) * alpha + (dst & 0xFF) * inv) / 255;
				out[gx] = (dst & 0xFF000000u) | (r << 16) | (g << 8) | b;
			}
		}
	}
}

void kon_measureText(kon_font_t *font, const char *text, int *outWidth, int *outHeight) {
	if (!font || !text) return;

	if (font->builtin) {
		int count = 0;

		for (const char *p = text; *p; p++) {
			unsigned char c = (unsigned char)*p;
			if (c >= KON_FONT_FIRST_CHAR && c < KON_FONT_FIRST_CHAR + KON_FONT_NUM_CHARS) count++;
		}
		if (outWidth) *outWidth = count * KON_BUILTIN_WIDTH * font->scale;
		if (outHeight) *outHeight = KON_BUILTIN_HEIGHT * font->scale;
		return;
	}

	float cursorX = 0.0f;
	float cursorY = 0.0f;
	float maxX = 0.0f;

	for (const char *p = text; *p; p++) {
		unsigned char c = (unsigned char)*p;

		if (c < KON_FONT_FIRST_CHAR || c >= KON_FONT_FIRST_CHAR + KON_FONT_NUM_CHARS) continue;

		stbtt_aligned_quad q;
		stbtt_GetBakedQuad(font->chardata, font->atlasSize, font->atlasSize, c - KON_FONT_FIRST_CHAR, &cursorX, &cursorY, &q, 0);

		if (cursorX > maxX) maxX = cursorX;
	}

	if (outWidth) *outWidth = (int)maxX;
	if (outHeight) *outHeight = (int)font->pixelHeight;
}

#endif /* KONFONT_IMPLEMENTATION */

#endif /* KONFONT_H */