/**********************************************************************************************
*
*   raylib.text - Basic functions to load Fonts and draw Text
*
*   CONFIGURATION:
*
*   #define SUPPORT_FILEFORMAT_FNT
*   #define SUPPORT_FILEFORMAT_TTF
*       Selected desired fileformats to be supported for loading. Some of those formats are
*       supported by default, to remove support, just comment unrequired #define in this module
*
*   #define SUPPORT_DEFAULT_FONT
*
*   DEPENDENCIES:
*       stb_truetype - Load TTF file and rasterize characters data
*
*
*   LICENSE: zlib/libpng
*
*   Copyright (c) 2014-2018 Ramon Santamaria (@raysan5)
*
*   This software is provided "as-is", without any express or implied warranty. In no event
*   will the authors be held liable for any damages arising from the use of this software.
*
*   Permission is granted to anyone to use this software for any purpose, including commercial
*   applications, and to alter it and redistribute it freely, subject to the following restrictions:
*
*     1. The origin of this software must not be misrepresented; you must not claim that you
*     wrote the original software. If you use this software in a product, an acknowledgment
*     in the product documentation would be appreciated but is not required.
*
*     2. Altered source versions must be plainly marked as such, and must not be misrepresented
*     as being the original software.
*
*     3. This notice may not be removed or altered from any source distribution.
*
**********************************************************************************************/

#include "config.h"         // Defines module configuration flags
#include "raylib.h"         // Declares module functions

#include <stdlib.h>         // Required for: malloc(), free()
#include <string.h>         // Required for: strlen()
#include <stdarg.h>         // Required for: va_list, va_start(), vfprintf(), va_end()
#include <stdio.h>          // Required for: FILE, fopen(), fclose(), fscanf(), feof(), rewind(), fgets()

#include "utils.h"          // Required for: fopen() Android mapping

#if defined(SUPPORT_FILEFORMAT_TTF)
    #define STB_RECT_PACK_IMPLEMENTATION
    #include "external/stb_rect_pack.h"     // Required for: ttf font rectangles packaging

    #define STBTT_STATIC
    #define STB_TRUETYPE_IMPLEMENTATION
    #include "external/stb_truetype.h"      // Required for: ttf font data reading
#endif

//----------------------------------------------------------------------------------
// Defines and Macros
//----------------------------------------------------------------------------------
#define MAX_FORMATTEXT_LENGTH  256
#define MAX_SUBTEXT_LENGTH     256

//----------------------------------------------------------------------------------
// Types and Structures Definition
//----------------------------------------------------------------------------------
// ...

//----------------------------------------------------------------------------------
// Global variables
//----------------------------------------------------------------------------------
#if defined(SUPPORT_DEFAULT_FONT)
static Font defaultFont;        // Default font provided by raylib
// NOTE: defaultFont is loaded on InitWindow and disposed on CloseWindow [module: core]
#endif

//----------------------------------------------------------------------------------
// Other Modules Functions Declaration (required by text)
//----------------------------------------------------------------------------------
//...

//----------------------------------------------------------------------------------
// Module specific Functions Declaration
//----------------------------------------------------------------------------------
static Font LoadImageFont(Image image, Color key, int firstChar); // Load a Image font file (XNA style)
#if defined(SUPPORT_FILEFORMAT_FNT)
static Font LoadBMFont(const char *fileName);     // Load a BMFont file (AngelCode font file)
#endif

#if defined(SUPPORT_DEFAULT_FONT)
extern void LoadDefaultFont(void);
extern void UnloadDefaultFont(void);
#endif

//----------------------------------------------------------------------------------
// Module Functions Definition
//----------------------------------------------------------------------------------
#if defined(SUPPORT_DEFAULT_FONT)

// Load raylib default font
extern void LoadDefaultFont(void)
{
    #define BIT_CHECK(a,b) ((a) & (1u << (b)))

    // NOTE: Using UTF8 encoding table for Unicode U+0000..U+00FF Basic Latin + Latin-1 Supplement
    // http://www.utf8-chartable.de/unicode-utf8-table.pl

    defaultFont.charsCount = 224;             // Number of chars included in our default font

    // Default font is directly defined here (data generated from a sprite font image)
    // This way, we reconstruct Font without creating large global variables
    // This data is automatically allocated to Stack and automatically deallocated at the end of this function
    int defaultFontData[512] = {
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00200020, 0x0001b000, 0x00000000, 0x00000000, 0x8ef92520, 0x00020a00, 0x7dbe8000, 0x1f7df45f,
        0x4a2bf2a0, 0x0852091e, 0x41224000, 0x10041450, 0x2e292020, 0x08220812, 0x41222000, 0x10041450, 0x10f92020, 0x3efa084c, 0x7d22103c, 0x107df7de,
        0xe8a12020, 0x08220832, 0x05220800, 0x10450410, 0xa4a3f000, 0x08520832, 0x05220400, 0x10450410, 0xe2f92020, 0x0002085e, 0x7d3e0281, 0x107df41f,
        0x00200000, 0x8001b000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0xc0000fbe, 0xfbf7e00f, 0x5fbf7e7d, 0x0050bee8, 0x440808a2, 0x0a142fe8, 0x50810285, 0x0050a048,
        0x49e428a2, 0x0a142828, 0x40810284, 0x0048a048, 0x10020fbe, 0x09f7ebaf, 0xd89f3e84, 0x0047a04f, 0x09e48822, 0x0a142aa1, 0x50810284, 0x0048a048,
        0x04082822, 0x0a142fa0, 0x50810285, 0x0050a248, 0x00008fbe, 0xfbf42021, 0x5f817e7d, 0x07d09ce8, 0x00008000, 0x00000fe0, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x000c0180,
        0xdfbf4282, 0x0bfbf7ef, 0x42850505, 0x004804bf, 0x50a142c6, 0x08401428, 0x42852505, 0x00a808a0, 0x50a146aa, 0x08401428, 0x42852505, 0x00081090,
        0x5fa14a92, 0x0843f7e8, 0x7e792505, 0x00082088, 0x40a15282, 0x08420128, 0x40852489, 0x00084084, 0x40a16282, 0x0842022a, 0x40852451, 0x00088082,
        0xc0bf4282, 0xf843f42f, 0x7e85fc21, 0x3e0900bf, 0x00000000, 0x00000004, 0x00000000, 0x000c0180, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x04000402, 0x41482000, 0x00000000, 0x00000800,
        0x04000404, 0x4100203c, 0x00000000, 0x00000800, 0xf7df7df0, 0x514bef85, 0xbefbefbe, 0x04513bef, 0x14414500, 0x494a2885, 0xa28a28aa, 0x04510820,
        0xf44145f0, 0x474a289d, 0xa28a28aa, 0x04510be0, 0x14414510, 0x494a2884, 0xa28a28aa, 0x02910a00, 0xf7df7df0, 0xd14a2f85, 0xbefbe8aa, 0x011f7be0,
        0x00000000, 0x00400804, 0x20080000, 0x00000000, 0x00000000, 0x00600f84, 0x20080000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0xac000000, 0x00000f01, 0x00000000, 0x00000000, 0x24000000, 0x00000f01, 0x00000000, 0x06000000, 0x24000000, 0x00000f01, 0x00000000, 0x09108000,
        0x24fa28a2, 0x00000f01, 0x00000000, 0x013e0000, 0x2242252a, 0x00000f52, 0x00000000, 0x038a8000, 0x2422222a, 0x00000f29, 0x00000000, 0x010a8000,
        0x2412252a, 0x00000f01, 0x00000000, 0x010a8000, 0x24fbe8be, 0x00000f01, 0x00000000, 0x0ebe8000, 0xac020000, 0x00000f01, 0x00000000, 0x00048000,
        0x0003e000, 0x00000f00, 0x00000000, 0x00008000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000038, 0x8443b80e, 0x00203a03,
        0x02bea080, 0xf0000020, 0xc452208a, 0x04202b02, 0xf8029122, 0x07f0003b, 0xe44b388e, 0x02203a02, 0x081e8a1c, 0x0411e92a, 0xf4420be0, 0x01248202,
        0xe8140414, 0x05d104ba, 0xe7c3b880, 0x00893a0a, 0x283c0e1c, 0x04500902, 0xc4400080, 0x00448002, 0xe8208422, 0x04500002, 0x80400000, 0x05200002,
        0x083e8e00, 0x04100002, 0x804003e0, 0x07000042, 0xf8008400, 0x07f00003, 0x80400000, 0x04000022, 0x00000000, 0x00000000, 0x80400000, 0x04000002,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00800702, 0x1848a0c2, 0x84010000, 0x02920921, 0x01042642, 0x00005121, 0x42023f7f, 0x00291002,
        0xefc01422, 0x7efdfbf7, 0xefdfa109, 0x03bbbbf7, 0x28440f12, 0x42850a14, 0x20408109, 0x01111010, 0x28440408, 0x42850a14, 0x2040817f, 0x01111010,
        0xefc78204, 0x7efdfbf7, 0xe7cf8109, 0x011111f3, 0x2850a932, 0x42850a14, 0x2040a109, 0x01111010, 0x2850b840, 0x42850a14, 0xefdfbf79, 0x03bbbbf7,
        0x001fa020, 0x00000000, 0x00001000, 0x00000000, 0x00002070, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x08022800, 0x00012283, 0x02430802, 0x01010001, 0x8404147c, 0x20000144, 0x80048404, 0x00823f08, 0xdfbf4284, 0x7e03f7ef, 0x142850a1, 0x0000210a,
        0x50a14684, 0x528a1428, 0x142850a1, 0x03efa17a, 0x50a14a9e, 0x52521428, 0x142850a1, 0x02081f4a, 0x50a15284, 0x4a221428, 0xf42850a1, 0x03efa14b,
        0x50a16284, 0x4a521428, 0x042850a1, 0x0228a17a, 0xdfbf427c, 0x7e8bf7ef, 0xf7efdfbf, 0x03efbd0b, 0x00000000, 0x04000000, 0x00000000, 0x00000008,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00200508, 0x00840400, 0x11458122, 0x00014210,
        0x00514294, 0x51420800, 0x20a22a94, 0x0050a508, 0x00200000, 0x00000000, 0x00050000, 0x08000000, 0xfefbefbe, 0xfbefbefb, 0xfbeb9114, 0x00fbefbe,
        0x20820820, 0x8a28a20a, 0x8a289114, 0x3e8a28a2, 0xfefbefbe, 0xfbefbe0b, 0x8a289114, 0x008a28a2, 0x228a28a2, 0x08208208, 0x8a289114, 0x088a28a2,
        0xfefbefbe, 0xfbefbefb, 0xfa2f9114, 0x00fbefbe, 0x00000000, 0x00000040, 0x00000000, 0x00000000, 0x00000000, 0x00000020, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00210100, 0x00000004, 0x00000000, 0x00000000, 0x14508200, 0x00001402, 0x00000000, 0x00000000,
        0x00000010, 0x00000020, 0x00000000, 0x00000000, 0xa28a28be, 0x00002228, 0x00000000, 0x00000000, 0xa28a28aa, 0x000022e8, 0x00000000, 0x00000000,
        0xa28a28aa, 0x000022a8, 0x00000000, 0x00000000, 0xa28a28aa, 0x000022e8, 0x00000000, 0x00000000, 0xbefbefbe, 0x00003e2f, 0x00000000, 0x00000000,
        0x00000004, 0x00002028, 0x00000000, 0x00000000, 0x80000000, 0x00003e0f, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 };

    int charsHeight = 10;
    int charsDivisor = 1;    // Every char is separated from the consecutive by a 1 pixel divisor, horizontally and vertically

    int charsWidth[224] = { 3, 1, 4, 6, 5, 7, 6, 2, 3, 3, 5, 5, 2, 4, 1, 7, 5, 2, 5, 5, 5, 5, 5, 5, 5, 5, 1, 1, 3, 4, 3, 6,
                            7, 6, 6, 6, 6, 6, 6, 6, 6, 3, 5, 6, 5, 7, 6, 6, 6, 6, 6, 6, 7, 6, 7, 7, 6, 6, 6, 2, 7, 2, 3, 5,
                            2, 5, 5, 5, 5, 5, 4, 5, 5, 1, 2, 5, 2, 5, 5, 5, 5, 5, 5, 5, 4, 5, 5, 5, 5, 5, 5, 3, 1, 3, 4, 4,
                            1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
                            1, 1, 5, 5, 5, 7, 1, 5, 3, 7, 3, 5, 4, 1, 7, 4, 3, 5, 3, 3, 2, 5, 6, 1, 2, 2, 3, 5, 6, 6, 6, 6,
                            6, 6, 6, 6, 6, 6, 7, 6, 6, 6, 6, 6, 3, 3, 3, 3, 7, 6, 6, 6, 6, 6, 6, 5, 6, 6, 6, 6, 6, 6, 4, 6,
                            5, 5, 5, 5, 5, 5, 9, 5, 5, 5, 5, 5, 2, 2, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 3, 5 };

    // Re-construct image from defaultFontData and generate OpenGL texture
    //----------------------------------------------------------------------
    int imWidth = 128;
    int imHeight = 128;

    Color *imagePixels = (Color *)malloc(imWidth*imHeight*sizeof(Color));

    for (int i = 0; i < imWidth*imHeight; i++) imagePixels[i] = BLANK;        // Initialize array

    int counter = 0;        // Font data elements counter

    // Fill imgData with defaultFontData (convert from bit to pixel!)
    for (int i = 0; i < imWidth*imHeight; i += 32)
    {
        for (int j = 31; j >= 0; j--)
        {
            if (BIT_CHECK(defaultFontData[counter], j)) imagePixels[i+j] = WHITE;
        }

        counter++;

        if (counter > 512) counter = 0;         // Security check...
    }

    //FILE *myimage = fopen("default_font.raw", "wb");
    //fwrite(image.pixels, 1, 128*128*4, myimage);
    //fclose(myimage);

    Image image = LoadImageEx(imagePixels, imWidth, imHeight);
    ImageFormat(&image, UNCOMPRESSED_GRAY_ALPHA);

    free(imagePixels);

    defaultFont.texture = LoadTextureFromImage(image);
    UnloadImage(image);

    // Reconstruct charSet using charsWidth[], charsHeight, charsDivisor, charsCount
    //------------------------------------------------------------------------------
    
    // Allocate space for our characters info data
    // NOTE: This memory should be freed at end! --> CloseWindow()
    defaultFont.chars = (CharInfo *)malloc(defaultFont.charsCount*sizeof(CharInfo));    

    int currentLine = 0;
    int currentPosX = charsDivisor;
    int testPosX = charsDivisor;

    for (int i = 0; i < defaultFont.charsCount; i++)
    {
        defaultFont.chars[i].value = 32 + i;  // First char is 32

        defaultFont.chars[i].rec.x = (float)currentPosX;
        defaultFont.chars[i].rec.y = (float)(charsDivisor + currentLine*(charsHeight + charsDivisor));
        defaultFont.chars[i].rec.width = (float)charsWidth[i];
        defaultFont.chars[i].rec.height = (float)charsHeight;

        testPosX += (int)(defaultFont.chars[i].rec.width + (float)charsDivisor);

        if (testPosX >= defaultFont.texture.width)
        {
            currentLine++;
            currentPosX = 2*charsDivisor + charsWidth[i];
            testPosX = currentPosX;

            defaultFont.chars[i].rec.x = (float)charsDivisor;
            defaultFont.chars[i].rec.y = (float)(charsDivisor + currentLine*(charsHeight + charsDivisor));
        }
        else currentPosX = testPosX;

        // NOTE: On default font character offsets and xAdvance are not required
        defaultFont.chars[i].offsetX = 0;
        defaultFont.chars[i].offsetY = 0;
        defaultFont.chars[i].advanceX = 0;
    }

    defaultFont.baseSize = (int)defaultFont.chars[0].rec.height;
    
    TraceLog(LOG_INFO, "[TEX ID %i] Default font loaded successfully", defaultFont.texture.id);
}

// Unload raylib default font
extern void UnloadDefaultFont(void)
{
    UnloadTexture(defaultFont.texture);
    free(defaultFont.chars);
}
#endif      // SUPPORT_DEFAULT_FONT

// Get the default font, useful to be used with extended parameters
Font GetFontDefault()
{
#if defined(SUPPORT_DEFAULT_FONT)
    return defaultFont;
#else
    Font font = { 0 };
    return font;
#endif   
}

// Load Font from file into GPU memory (VRAM)
Font LoadFont(const char *fileName)
{
    // Default hardcoded values for ttf file loading
    #define DEFAULT_TTF_FONTSIZE    32      // Font first character (32 - space)
    #define DEFAULT_TTF_NUMCHARS    95      // ASCII 32..126 is 95 glyphs
    #define DEFAULT_FIRST_CHAR      32      // Expected first char for image sprite font

    Font font = { 0 };

#if defined(SUPPORT_FILEFORMAT_TTF)
    if (IsFileExtension(fileName, ".ttf"))
    {
        font.baseSize = DEFAULT_TTF_FONTSIZE;
        font.charsCount = DEFAULT_TTF_NUMCHARS;
        font.chars = LoadFontData(fileName, font.baseSize, NULL, font.charsCount, FONT_DEFAULT);
        Image atlas = GenImageFontAtlas(font.chars, font.charsCount, font.baseSize, 4, 0);
        font.texture = LoadTextureFromImage(atlas);
        UnloadImage(atlas);
    }
    else
#endif
#if defined(SUPPORT_FILEFORMAT_FNT)
    if (IsFileExtension(fileName, ".fnt")) font = LoadBMFont(fileName);
    else
#endif
    {
        Image image = LoadImage(fileName);
        if (image.data != NULL) font = LoadImageFont(image, MAGENTA, DEFAULT_FIRST_CHAR);
        UnloadImage(image);
    }

    if (font.texture.id == 0)
    {
        TraceLog(LOG_WARNING, "[%s] Font could not be loaded, using default font", fileName);
        font = GetFontDefault();
    }
    else SetTextureFilter(font.texture, FILTER_POINT);    // By default we set point filter (best performance)

    return font;
}

// Load Font from TTF font file with generation parameters
// NOTE: You can pass an array with desired characters, those characters should be available in the font
// if array is NULL, default char set is selected 32..126
Font LoadFontEx(const char *fileName, int fontSize, int charsCount, int *fontChars)
{
    Font font = { 0 };
    
    font.baseSize = fontSize;
    font.charsCount = (charsCount > 0) ? charsCount : 95;
    font.chars = LoadFontData(fileName, font.baseSize, fontChars, font.charsCount, FONT_DEFAULT);
    Image atlas = GenImageFontAtlas(font.chars, font.charsCount, font.baseSize, 2, 0);
    font.texture = LoadTextureFromImage(atlas);
    UnloadImage(atlas);
    
    return font;
}

// Load font data for further use
// NOTE: Requires TTF font and can generate SDF data
CharInfo *LoadFontData(const char *fileName, int fontSize, int *fontChars, int charsCount, int type)
{
    // NOTE: Using some SDF generation default values,
    // trades off precision with ability to handle *smaller* sizes
    #define SDF_CHAR_PADDING            4
    #define SDF_ON_EDGE_VALUE         128
    #define SDF_PIXEL_DIST_SCALE     64.0f
    
    #define BITMAP_ALPHA_THRESHOLD     80
    
    // In case no chars count provided, default to 95
    charsCount = (charsCount > 0) ? charsCount : 95;
    
    CharInfo *chars = (CharInfo *)malloc(charsCount*sizeof(CharInfo));
    
    // Load font data (including pixel data) from TTF file
    // NOTE: Loaded information should be enough to generate font image atlas,
    // using any packaging method
    FILE *fontFile = fopen(fileName, "rb");     // Load font file
    
    fseek(fontFile, 0, SEEK_END);
    long size = ftell(fontFile);    // Get file size
    fseek(fontFile, 0, SEEK_SET);   // Reset file pointer
    
    unsigned char *fontBuffer = (unsigned char *)malloc(size);
    
    fread(fontBuffer, size, 1, fontFile);
    fclose(fontFile);
    
    // Init font for data reading
    stbtt_fontinfo fontInfo;
    if (!stbtt_InitFont(&fontInfo, fontBuffer, 0)) TraceLog(LOG_WARNING, "Failed to init font!");

    // Calculate font scale factor
    float scaleFactor = stbtt_ScaleForPixelHeight(&fontInfo, (float)fontSize);

    // Calculate font basic metrics
    // NOTE: ascent is equivalent to font baseline
    int ascent, descent, lineGap;
    stbtt_GetFontVMetrics(&fontInfo, &ascent, &descent, &lineGap);
    
    // Fill fontChars in case not provided externally
    // NOTE: By default we fill charsCount consecutevely, starting at 32 (Space)
    int genFontChars = false;
    if (fontChars == NULL) genFontChars = true;   
    if (genFontChars) 
    {
        fontChars = (int *)malloc(charsCount*sizeof(int));
        for (int i = 0; i < charsCount; i++) fontChars[i] = i + 32;
    }
    
    // NOTE: Using simple packaging, one char after another
    for (int i = 0; i < charsCount; i++) 
    {
        int chw = 0, chh = 0;   // Character width and height (on generation)
        int ch = fontChars[i];  // Character value to get info for
        chars[i].value = ch;
        
        //  Render a unicode codepoint to a bitmap
        //      stbtt_GetCodepointBitmap()           -- allocates and returns a bitmap
        //      stbtt_GetCodepointBitmapBox()        -- how big the bitmap must be
        //      stbtt_MakeCodepointBitmap()          -- renders into bitmap you provide
        
        if (type != FONT_SDF) chars[i].data = stbtt_GetCodepointBitmap(&fontInfo, scaleFactor, scaleFactor, ch, &chw, &chh, &chars[i].offsetX, &chars[i].offsetY);
        else if (ch != 32) chars[i].data = stbtt_GetCodepointSDF(&fontInfo, scaleFactor, ch, SDF_CHAR_PADDING, SDF_ON_EDGE_VALUE, SDF_PIXEL_DIST_SCALE, &chw, &chh, &chars[i].offsetX, &chars[i].offsetY);
        
        if (type == FONT_BITMAP)
        {
            // Aliased bitmap (black & white) font generation, avoiding anti-aliasing
            // NOTE: For optimum results, bitmap font should be generated at base pixel size
            for (int p = 0; p < chw*chh; p++)
            {
                if (chars[i].data[p] < BITMAP_ALPHA_THRESHOLD) chars[i].data[p] = 0;
                else chars[i].data[p] = 255;
            }
        }
        
        chars[i].rec.width = (float)chw;
        chars[i].rec.height = (float)chh;
        chars[i].offsetY += (int)((float)ascent*scaleFactor);
    
        // Get bounding box for character (may be offset to account for chars that dip above or below the line)
        int chX1, chY1, chX2, chY2;
        stbtt_GetCodepointBitmapBox(&fontInfo, ch, scaleFactor, scaleFactor, &chX1, &chY1, &chX2, &chY2);
        
        TraceLog(LOG_DEBUG, "Character box measures: %i, %i, %i, %i", chX1, chY1, chX2 - chX1, chY2 - chY1);
        TraceLog(LOG_DEBUG, "Character offsetY: %i", (int)((float)ascent*scaleFactor) + chY1);

        stbtt_GetCodepointHMetrics(&fontInfo, ch, &chars[i].advanceX, NULL);
        chars[i].advanceX *= scaleFactor;
    }
    
    free(fontBuffer);
    if (genFontChars) free(fontChars);
    
    return chars;
}

// Generate image font atlas using chars info
// NOTE: Packing method: 0-Default, 1-Skyline
Image GenImageFontAtlas(CharInfo *chars, int charsCount, int fontSize, int padding, int packMethod)
{
    Image atlas = { 0 };
    
    // In case no chars count provided we suppose default of 95
    charsCount = (charsCount > 0) ? charsCount : 95;
    
    // Calculate image size based on required pixel area
    // NOTE 1: Image is forced to be squared and POT... very conservative!
    // NOTE 2: SDF font characters already contain an internal padding, 
    // so image size would result bigger than default font type
    float requiredArea = 0;
    for (int i = 0; i < charsCount; i++) requiredArea += ((chars[i].rec.width + 2*padding)*(chars[i].rec.height + 2*padding));
    float guessSize = sqrtf(requiredArea)*1.25f;
    int imageSize = (int)powf(2, ceilf(logf((float)guessSize)/logf(2)));  // Calculate next POT
    
    atlas.width = imageSize;   // Atlas bitmap width
    atlas.height = imageSize;  // Atlas bitmap height
    atlas.data = (unsigned char *)calloc(1, atlas.width*atlas.height);      // Create a bitmap to store characters (8 bpp)
    atlas.format = UNCOMPRESSED_GRAYSCALE;
    atlas.mipmaps = 1;
    
    // DEBUG: We can see padding in the generated image setting a gray background...
    //for (int i = 0; i < atlas.width*atlas.height; i++) ((unsigned char *)atlas.data)[i] = 100;

    if (packMethod == 0)   // Use basic packing algorythm
    {
        int offsetX = padding;
        int offsetY = padding;
        
        // NOTE: Using simple packaging, one char after another
        for (int i = 0; i < charsCount; i++) 
        {
            // Copy pixel data from fc.data to atlas
            for (int y = 0; y < (int)chars[i].rec.height; y++)
            {
                for (int x = 0; x < (int)chars[i].rec.width; x++)
                {
                    ((unsigned char *)atlas.data)[(offsetY + y)*atlas.width + (offsetX + x)] = chars[i].data[y*(int)chars[i].rec.width + x];
                }
            }
            
            chars[i].rec.x = (float)offsetX;
            chars[i].rec.y = (float)offsetY;
            
            // Move atlas position X for next character drawing
            offsetX += ((int)chars[i].rec.width + 2*padding);
            
            if (offsetX >= (atlas.width - (int)chars[i].rec.width - padding))
            {
                offsetX = padding;
                
                // NOTE: Be careful on offsetY for SDF fonts, by default SDF 
                // use an internal padding of 4 pixels, it means char rectangle
                // height is bigger than fontSize, it could be up to (fontSize + 8)
                offsetY += (fontSize + 2*padding);
                
                if (offsetY > (atlas.height - fontSize - padding)) break;
            }
        }
    }
    else if (packMethod == 1)  // Use Skyline rect packing algorythm (stb_pack_rect)
    {
        TraceLog(LOG_DEBUG, "Using Skyline packing algorythm!");
        
        stbrp_context *context = (stbrp_context *)malloc(sizeof(*context));
        stbrp_node *nodes = (stbrp_node *)malloc(charsCount*sizeof(*nodes));

        stbrp_init_target(context, atlas.width, atlas.height, nodes, charsCount);
        stbrp_rect *rects = (stbrp_rect *)malloc(charsCount*sizeof(stbrp_rect));
        
        // Fill rectangles for packaging
        for (int i = 0; i < charsCount; i++)
        {
            rects[i].id = i;
            rects[i].w = (int)chars[i].rec.width + 2*padding;
            rects[i].h = (int)chars[i].rec.height + 2*padding;
        }

        // Package rectangles into atlas
        stbrp_pack_rects(context, rects, charsCount);
        
        for (int i = 0; i < charsCount; i++)
        {
            chars[i].rec.x = rects[i].x + (float)padding;
            chars[i].rec.y = rects[i].y + (float)padding;
            
            if (rects[i].was_packed)
            {
                // Copy pixel data from fc.data to atlas
                for (int y = 0; y < (int)chars[i].rec.height; y++)
                {
                    for (int x = 0; x < (int)chars[i].rec.width; x++)
                    {
                        ((unsigned char *)atlas.data)[(rects[i].y + padding + y)*atlas.width + (rects[i].x + padding + x)] = chars[i].data[y*(int)chars[i].rec.width + x];
                    }
                }
            }
            else TraceLog(LOG_WARNING, "Character could not be packed: %i", i);
        }

        free(nodes);
        free(context);
    }
    
    // TODO: Crop image if required for smaller size
    
    // Convert image data from GRAYSCALE to GRAY_ALPHA
    // WARNING: ImageAlphaMask(&atlas, atlas) does not work in this case, requires manual operation
    unsigned char *dataGrayAlpha = (unsigned char *)malloc(imageSize*imageSize*sizeof(unsigned char)*2); // Two channels

    for (int i = 0, k = 0; i < atlas.width*atlas.height; i++, k += 2)
    {
        dataGrayAlpha[k] = 255;
        dataGrayAlpha[k + 1] = ((unsigned char *)atlas.data)[i];
    }

    free(atlas.data);
    atlas.data = dataGrayAlpha;
    atlas.format = UNCOMPRESSED_GRAY_ALPHA;
    
    return atlas;
}

// Unload Font from GPU memory (VRAM)
void UnloadFont(Font font)
{
    // NOTE: Make sure spriteFont is not default font (fallback)
    if (font.texture.id != GetFontDefault().texture.id)
    {
        UnloadTexture(font.texture);
        free(font.chars);

        TraceLog(LOG_DEBUG, "Unloaded sprite font data");
    }
}

// Draw text (using default font)
// NOTE: fontSize work like in any drawing program but if fontSize is lower than font-base-size, then font-base-size is used
// NOTE: chars spacing is proportional to fontSize
void DrawText(const char *text, int posX, int posY, int fontSize, Color color)
{
    // Check if default font has been loaded
    if (GetFontDefault().texture.id != 0)
    {
        Vector2 position = { (float)posX, (float)posY };

        int defaultFontSize = 10;   // Default Font chars height in pixel
        if (fontSize < defaultFontSize) fontSize = defaultFontSize;
        int spacing = fontSize/defaultFontSize;

        DrawTextEx(GetFontDefault(), text, position, (float)fontSize, (float)spacing, color);
    }
}

// Draw text using Font
// NOTE: chars spacing is NOT proportional to fontSize
void DrawTextEx(Font font, const char *text, Vector2 position, float fontSize, float spacing, Color tint)
{
    int length = strlen(text);
    int textOffsetX = 0;        // Offset between characters
    int textOffsetY = 0;        // Required for line break!
    float scaleFactor;

    unsigned char letter;       // Current character
    int index;                  // Index position in sprite font

    scaleFactor = fontSize/font.baseSize;

    // NOTE: Some ugly hacks are made to support Latin-1 Extended characters directly
    // written in C code files (codified by default as UTF-8)

    for (int i = 0; i < length; i++)
    {
        if ((unsigned char)text[i] == '\n')
        {
            // NOTE: Fixed line spacing of 1.5 lines
            textOffsetY += (int)((font.baseSize + font.baseSize/2)*scaleFactor);
            textOffsetX = 0;
        }
        else
        {
            if ((unsigned char)text[i] == 0xc2)         // UTF-8 encoding identification HACK!
            {
                // Support UTF-8 encoded values from [0xc2 0x80] -> [0xc2 0xbf](¿)
                letter = (unsigned char)text[i + 1];
                index = GetGlyphIndex(font, (int)letter);
                i++;
            }
            else if ((unsigned char)text[i] == 0xc3)    // UTF-8 encoding identification HACK!
            {
                // Support UTF-8 encoded values from [0xc3 0x80](À) -> [0xc3 0xbf](ÿ)
                letter = (unsigned char)text[i + 1];
                index = GetGlyphIndex(font, (int)letter + 64);
                i++;
            }
            else index = GetGlyphIndex(font, (unsigned char)text[i]);
            
            if ((unsigned char)text[i] != ' ')
            {
                DrawTexturePro(font.texture, font.chars[index].rec,
                           (Rectangle){ position.x + textOffsetX + font.chars[index].offsetX*scaleFactor,
                                        position.y + textOffsetY + font.chars[index].offsetY*scaleFactor,
                                        font.chars[index].rec.width*scaleFactor,
                                        font.chars[index].rec.height*scaleFactor }, (Vector2){ 0, 0 }, 0.0f, tint);
            }

            if (font.chars[index].advanceX == 0) textOffsetX += (int)(font.chars[index].rec.width*scaleFactor + spacing);
            else textOffsetX += (int)(font.chars[index].advanceX*scaleFactor + spacing);
        }
    }
}

// Formatting of text with variables to 'embed'
const char *FormatText(const char *text, ...)
{
    static char buffer[MAX_FORMATTEXT_LENGTH];

    va_list args;
    va_start(args, text);
    vsprintf(buffer, text, args);
    va_end(args);

    return buffer;
}

// Get a piece of a text string
const char *SubText(const char *text, int position, int length)
{
    static char buffer[MAX_SUBTEXT_LENGTH];
    int textLength = strlen(text);

    if (position >= textLength)
    {
        position = textLength - 1;
        length = 0;
    }

    if (length >= textLength) length = textLength;

    for (int c = 0 ; c < length ; c++)
    {
        *(buffer + c) = *(text + position);
        text++;
    }

    *(buffer + length) = '\0';

    return buffer;
}

// Measure string width for default font
int MeasureText(const char *text, int fontSize)
{
    Vector2 vec = { 0.0f, 0.0f };

    // Check if default font has been loaded
    if (GetFontDefault().texture.id != 0)
    {
        int defaultFontSize = 10;   // Default Font chars height in pixel
        if (fontSize < defaultFontSize) fontSize = defaultFontSize;
        int spacing = fontSize/defaultFontSize;

        vec = MeasureTextEx(GetFontDefault(), text, (float)fontSize, (float)spacing);
    }

    return (int)vec.x;
}

// Measure string size for Font
Vector2 MeasureTextEx(Font font, const char *text, float fontSize, float spacing)
{
    int len = strlen(text);
    int tempLen = 0;                // Used to count longer text line num chars
    int lenCounter = 0;

    float textWidth = 0;
    float tempTextWidth = 0;        // Used to count longer text line width

    float textHeight = (float)font.baseSize;
    float scaleFactor = fontSize/(float)font.baseSize;

    for (int i = 0; i < len; i++)
    {
        lenCounter++;

        if (text[i] != '\n')
        {
            int index = GetGlyphIndex(font, (int)text[i]);

            if (font.chars[index].advanceX != 0) textWidth += font.chars[index].advanceX;
            else textWidth += (font.chars[index].rec.width + font.chars[index].offsetX);
        }
        else
        {
            if (tempTextWidth < textWidth) tempTextWidth = textWidth;
            lenCounter = 0;
            textWidth = 0;
            textHeight += ((float)font.baseSize*1.5f); // NOTE: Fixed line spacing of 1.5 lines
        }

        if (tempLen < lenCounter) tempLen = lenCounter;
    }

    if (tempTextWidth < textWidth) tempTextWidth = textWidth;

    Vector2 vec;
    vec.x = tempTextWidth*scaleFactor + (float)((tempLen - 1)*spacing); // Adds chars spacing to measure
    vec.y = textHeight*scaleFactor;

    return vec;
}

// Returns index position for a unicode character on spritefont
int GetGlyphIndex(Font font, int character)
{
#define UNORDERED_CHARSET
#if defined(UNORDERED_CHARSET)
    int index = 0;

    for (int i = 0; i < font.charsCount; i++)
    {
        if (font.chars[i].value == character)
        {
            index = i;
            break;
        }
    }

    return index;
#else
    return (character - 32);
#endif
}

// Shows current FPS on top-left corner
// NOTE: Uses default font
void DrawFPS(int posX, int posY)
{
    // NOTE: We are rendering fps every second for better viewing on high framerates

    static int fps = 0;
    static int counter = 0;
    static int refreshRate = 20;

    if (counter < refreshRate) counter++;
    else
    {
        fps = GetFPS();
        refreshRate = fps;
        counter = 0;
    }
    
    // NOTE: We have rounding errors every frame, so it oscillates a lot
    DrawText(FormatText("%2i FPS", fps), posX, posY, 20, LIME);
}

//----------------------------------------------------------------------------------
// Module specific Functions Definition
//----------------------------------------------------------------------------------

// Load an Image font file (XNA style)
static Font LoadImageFont(Image image, Color key, int firstChar)
{
    #define COLOR_EQUAL(col1, col2) ((col1.r == col2.r)&&(col1.g == col2.g)&&(col1.b == col2.b)&&(col1.a == col2.a))

    int charSpacing = 0;
    int lineSpacing = 0;

    int x = 0;
    int y = 0;

    // Default number of characters supported
    #define MAX_FONTCHARS          256

    // We allocate a temporal arrays for chars data measures,
    // once we get the actual number of chars, we copy data to a sized arrays
    int tempCharValues[MAX_FONTCHARS];
    Rectangle tempCharRecs[MAX_FONTCHARS];

    Color *pixels = GetImageData(image);

    // Parse image data to get charSpacing and lineSpacing
    for (y = 0; y < image.height; y++)
    {
        for (x = 0; x < image.width; x++)
        {
            if (!COLOR_EQUAL(pixels[y*image.width + x], key)) break;
        }
        
        if (!COLOR_EQUAL(pixels[y*image.width + x], key)) break;
    }

    charSpacing = x;
    lineSpacing = y;

    int charHeight = 0;
    int j = 0;

    while (!COLOR_EQUAL(pixels[(lineSpacing + j)*image.width + charSpacing], key)) j++;

    charHeight = j;

    // Check array values to get characters: value, x, y, w, h
    int index = 0;
    int lineToRead = 0;
    int xPosToRead = charSpacing;

    // Parse image data to get rectangle sizes
    while ((lineSpacing + lineToRead*(charHeight + lineSpacing)) < image.height)
    {
        while ((xPosToRead < image.width) &&
              !COLOR_EQUAL((pixels[(lineSpacing + (charHeight+lineSpacing)*lineToRead)*image.width + xPosToRead]), key))
        {
            tempCharValues[index] = firstChar + index;

            tempCharRecs[index].x = (float)xPosToRead;
            tempCharRecs[index].y = (float)(lineSpacing + lineToRead*(charHeight + lineSpacing));
            tempCharRecs[index].height = (float)charHeight;

            int charWidth = 0;

            while (!COLOR_EQUAL(pixels[(lineSpacing + (charHeight+lineSpacing)*lineToRead)*image.width + xPosToRead + charWidth], key)) charWidth++;

            tempCharRecs[index].width = (float)charWidth;

            index++;

            xPosToRead += (charWidth + charSpacing);
        }

        lineToRead++;
        xPosToRead = charSpacing;
    }

    TraceLog(LOG_DEBUG, "Font data parsed correctly from image");

    // NOTE: We need to remove key color borders from image to avoid weird
    // artifacts on texture scaling when using FILTER_BILINEAR or FILTER_TRILINEAR
    for (int i = 0; i < image.height*image.width; i++) if (COLOR_EQUAL(pixels[i], key)) pixels[i] = BLANK;

    // Create a new image with the processed color data (key color replaced by BLANK)
    Image fontClear = LoadImageEx(pixels, image.width, image.height);

    free(pixels);    // Free pixels array memory

    // Create spritefont with all data parsed from image
    Font spriteFont = { 0 };

    spriteFont.texture = LoadTextureFromImage(fontClear); // Convert processed image to OpenGL texture
    spriteFont.charsCount = index;

    UnloadImage(fontClear);     // Unload processed image once converted to texture

    // We got tempCharValues and tempCharsRecs populated with chars data
    // Now we move temp data to sized charValues and charRecs arrays
    spriteFont.chars = (CharInfo *)malloc(spriteFont.charsCount*sizeof(CharInfo));

    for (int i = 0; i < spriteFont.charsCount; i++)
    {
        spriteFont.chars[i].value = tempCharValues[i];
        spriteFont.chars[i].rec = tempCharRecs[i];

        // NOTE: On image based fonts (XNA style), character offsets and xAdvance are not required (set to 0)
        spriteFont.chars[i].offsetX = 0;
        spriteFont.chars[i].offsetY = 0;
        spriteFont.chars[i].advanceX = 0;
    }

    spriteFont.baseSize = (int)spriteFont.chars[0].rec.height;

    TraceLog(LOG_INFO, "Image file loaded correctly as Font");

    return spriteFont;
}

#if defined(SUPPORT_FILEFORMAT_FNT)
// Load a BMFont file (AngelCode font file)
static Font LoadBMFont(const char *fileName)
{
    #define MAX_BUFFER_SIZE     256

    Font font = { 0 };
    font.texture.id = 0;

    char buffer[MAX_BUFFER_SIZE];
    char *searchPoint = NULL;

    int fontSize = 0;
    int texWidth, texHeight;
    char texFileName[129];
    int charsCount = 0;

    int base;   // Useless data

    FILE *fntFile;

    fntFile = fopen(fileName, "rt");

    if (fntFile == NULL)
    {
        TraceLog(LOG_WARNING, "[%s] FNT file could not be opened", fileName);
        return font;
    }

    // NOTE: We skip first line, it contains no useful information
    fgets(buffer, MAX_BUFFER_SIZE, fntFile);
    //searchPoint = strstr(buffer, "size");
    //sscanf(searchPoint, "size=%i", &fontSize);

    fgets(buffer, MAX_BUFFER_SIZE, fntFile);
    searchPoint = strstr(buffer, "lineHeight");
    sscanf(searchPoint, "lineHeight=%i base=%i scaleW=%i scaleH=%i", &fontSize, &base, &texWidth, &texHeight);

    TraceLog(LOG_DEBUG, "[%s] Font size: %i", fileName, fontSize);
    TraceLog(LOG_DEBUG, "[%s] Font texture scale: %ix%i", fileName, texWidth, texHeight);

    fgets(buffer, MAX_BUFFER_SIZE, fntFile);
    searchPoint = strstr(buffer, "file");
    sscanf(searchPoint, "file=\"%128[^\"]\"", texFileName);

    TraceLog(LOG_DEBUG, "[%s] Font texture filename: %s", fileName, texFileName);

    fgets(buffer, MAX_BUFFER_SIZE, fntFile);
    searchPoint = strstr(buffer, "count");
    sscanf(searchPoint, "count=%i", &charsCount);

    TraceLog(LOG_DEBUG, "[%s] Font num chars: %i", fileName, charsCount);

    // Compose correct path using route of .fnt file (fileName) and texFileName
    char *texPath = NULL;
    char *lastSlash = NULL;

    lastSlash = strrchr(fileName, '/');

    // NOTE: We need some extra space to avoid memory corruption on next allocations!
    texPath = malloc(strlen(fileName) - strlen(lastSlash) + strlen(texFileName) + 4);

    // NOTE: strcat() and strncat() required a '\0' terminated string to work!
    *texPath = '\0';
    strncat(texPath, fileName, strlen(fileName) - strlen(lastSlash) + 1);
    strncat(texPath, texFileName, strlen(texFileName));

    TraceLog(LOG_DEBUG, "[%s] Font texture loading path: %s", fileName, texPath);

    Image imFont = LoadImage(texPath);

    if (imFont.format == UNCOMPRESSED_GRAYSCALE)
    {
        Image imCopy = ImageCopy(imFont);

        for (int i = 0; i < imCopy.width*imCopy.height; i++) ((unsigned char *)imCopy.data)[i] = 0xff;

        ImageAlphaMask(&imCopy, imFont);
        font.texture = LoadTextureFromImage(imCopy);
        UnloadImage(imCopy);
    }
    else font.texture = LoadTextureFromImage(imFont);
    
    UnloadImage(imFont);
    free(texPath);
    

    // Fill font characters info data
    font.baseSize = fontSize;
    font.charsCount = charsCount;
    font.chars = (CharInfo *)malloc(charsCount*sizeof(CharInfo));

    int charId, charX, charY, charWidth, charHeight, charOffsetX, charOffsetY, charAdvanceX;

    for (int i = 0; i < charsCount; i++)
    {
        fgets(buffer, MAX_BUFFER_SIZE, fntFile);
        sscanf(buffer, "char id=%i x=%i y=%i width=%i height=%i xoffset=%i yoffset=%i xadvance=%i",
                       &charId, &charX, &charY, &charWidth, &charHeight, &charOffsetX, &charOffsetY, &charAdvanceX);

        // Save data properly in sprite font
        font.chars[i].value = charId;
        font.chars[i].rec = (Rectangle){ (float)charX, (float)charY, (float)charWidth, (float)charHeight };
        font.chars[i].offsetX = charOffsetX;
        font.chars[i].offsetY = charOffsetY;
        font.chars[i].advanceX = charAdvanceX;
    }

    fclose(fntFile);

    if (font.texture.id == 0)
    {
        UnloadFont(font);
        font = GetFontDefault();
    }
    else TraceLog(LOG_INFO, "[%s] Font loaded successfully", fileName);

    return font;
}
#endif