[rtext] Add BDF font support (#3735)

* Add BDF font support

* Include font ascent in glyph y-offset when loading BDF font

2 files changed, 336 insertions, 25 deletions

diff --git a/src/config.h b/src/config.h
index 410e9067..34d2e964 100644
--- a/src/config.h
+++ b/src/config.h
@@ -181,6 +181,7 @@
 // Selected desired font fileformats to be supported for loading
 #define SUPPORT_FILEFORMAT_FNT          1
 #define SUPPORT_FILEFORMAT_TTF          1
+#define SUPPORT_FILEFORMAT_BDF          1
 
 // Support text management functions
 // If not defined, still some functions are supported: TextLength(), TextFormat()
diff --git a/src/rtext.c b/src/rtext.c
index 22c2e5e4..0cd90a59 100644
--- a/src/rtext.c
+++ b/src/rtext.c
@@ -12,6 +12,7 @@
 *
 *       #define SUPPORT_FILEFORMAT_FNT
 *       #define SUPPORT_FILEFORMAT_TTF
+*       #define SUPPORT_FILEFORMAT_BDF
 *           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
 *
@@ -70,14 +71,27 @@
 #include <stdarg.h>         // Required for: va_list, va_start(), vsprintf(), va_end() [Used in TextFormat()]
 #include <ctype.h>          // Required for: toupper(), tolower() [Used in TextToUpper(), TextToLower()]
 
-#if defined(SUPPORT_FILEFORMAT_TTF)
+#if defined(SUPPORT_FILEFORMAT_TTF) || defined(SUPPORT_FILEFORMAT_BDF)
     #if defined(__GNUC__) // GCC and Clang
         #pragma GCC diagnostic push
         #pragma GCC diagnostic ignored "-Wunused-function"
     #endif
 
     #define STB_RECT_PACK_IMPLEMENTATION
-    #include "external/stb_rect_pack.h"     // Required for: ttf font rectangles packaging
+    #include "external/stb_rect_pack.h"     // Required for: ttf/bdf font rectangles packaging
+
+    #include <math.h>   // Required for: ttf/bdf font rectangles packaging
+
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic pop
+    #endif
+#endif
+
+#if defined(SUPPORT_FILEFORMAT_TTF)
+    #if defined(__GNUC__) // GCC and Clang
+        #pragma GCC diagnostic push
+        #pragma GCC diagnostic ignored "-Wunused-function"
+    #endif
 
     #define STBTT_STATIC
     #define STB_TRUETYPE_IMPLEMENTATION
@@ -127,6 +141,9 @@ static Font defaultFont = { 0 };
 #if defined(SUPPORT_FILEFORMAT_FNT)
 static Font LoadBMFont(const char *fileName);   // Load a BMFont file (AngelCode font file)
 #endif
+#if defined(SUPPORT_FILEFORMAT_BDF)
+static GlyphInfo *LoadBDFFontData(const unsigned char *fileData, int dataSize, int *codepoints, int codepointCount, int* outFontSize);
+#endif
 static int textLineSpacing = 15;                // Text vertical line spacing in pixels
 
 #if defined(SUPPORT_DEFAULT_FONT)
@@ -335,6 +352,10 @@ Font LoadFont(const char *fileName)
     if (IsFileExtension(fileName, ".fnt")) font = LoadBMFont(fileName);
     else
 #endif
+#if defined(SUPPORT_FILEFORMAT_BDF)
+    if (IsFileExtension(fileName, ".bdf")) font = LoadFontEx(fileName, FONT_TTF_DEFAULT_SIZE, NULL, FONT_TTF_DEFAULT_NUMCHARS);
+    else
+#endif
     {
         Image image = LoadImage(fileName);
         if (image.data != NULL) font = LoadFontFromImage(image, MAGENTA, FONT_TTF_DEFAULT_FIRST_CHAR);
@@ -355,7 +376,7 @@ Font LoadFont(const char *fileName)
     return font;
 }
 
-// Load Font from TTF font file with generation parameters
+// Load Font from TTF or BDF 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 *codepoints, int codepointCount)
@@ -511,35 +532,49 @@ Font LoadFontFromMemory(const char *fileType, const unsigned char *fileData, int
     char fileExtLower[16] = { 0 };
     strcpy(fileExtLower, TextToLower(fileType));
 
-#if defined(SUPPORT_FILEFORMAT_TTF)
+    font.baseSize = fontSize;
+    font.glyphCount = (codepointCount > 0)? codepointCount : 95;
+    font.glyphPadding = 0;
+
+#if defined(SUPPORT_FILEFORMAT_TTF) 
     if (TextIsEqual(fileExtLower, ".ttf") ||
         TextIsEqual(fileExtLower, ".otf"))
     {
-        font.baseSize = fontSize;
-        font.glyphCount = (codepointCount > 0)? codepointCount : 95;
-        font.glyphPadding = 0;
         font.glyphs = LoadFontData(fileData, dataSize, font.baseSize, codepoints, font.glyphCount, FONT_DEFAULT);
+    }
+    else
+#endif
+#if defined(SUPPORT_FILEFORMAT_BDF)
+    if (TextIsEqual(fileExtLower, ".bdf"))
+    {
+        font.glyphs = LoadBDFFontData(fileData, dataSize, codepoints, font.glyphCount, &font.baseSize);
+    }
+    else
+#endif
+    {
+        font.glyphs = NULL;
+    }
 
-        if (font.glyphs != NULL)
-        {
-            font.glyphPadding = FONT_TTF_DEFAULT_CHARS_PADDING;
+#if defined(SUPPORT_FILEFORMAT_TTF) || defined(SUPPORT_FILEFORMAT_BDF)
+    if (font.glyphs != NULL)
+    {
+        font.glyphPadding = FONT_TTF_DEFAULT_CHARS_PADDING;
 
-            Image atlas = GenImageFontAtlas(font.glyphs, &font.recs, font.glyphCount, font.baseSize, font.glyphPadding, 0);
-            font.texture = LoadTextureFromImage(atlas);
+        Image atlas = GenImageFontAtlas(font.glyphs, &font.recs, font.glyphCount, font.baseSize, font.glyphPadding, 0);
+        font.texture = LoadTextureFromImage(atlas);
 
-            // Update glyphs[i].image to use alpha, required to be used on ImageDrawText()
-            for (int i = 0; i < font.glyphCount; i++)
-            {
-                UnloadImage(font.glyphs[i].image);
-                font.glyphs[i].image = ImageFromImage(atlas, font.recs[i]);
-            }
+        // Update glyphs[i].image to use alpha, required to be used on ImageDrawText()
+        for (int i = 0; i < font.glyphCount; i++)
+        {
+            UnloadImage(font.glyphs[i].image);
+            font.glyphs[i].image = ImageFromImage(atlas, font.recs[i]);
+        }
 
-            UnloadImage(atlas);
+        UnloadImage(atlas);
 
-            TRACELOG(LOG_INFO, "FONT: Data loaded successfully (%i pixel size | %i glyphs)", font.baseSize, font.glyphCount);
-        }
-        else font = GetFontDefault();
+        TRACELOG(LOG_INFO, "FONT: Data loaded successfully (%i pixel size | %i glyphs)", font.baseSize, font.glyphCount);
     }
+    else font = GetFontDefault();
 #else
     font = GetFontDefault();
 #endif
@@ -699,7 +734,7 @@ GlyphInfo *LoadFontData(const unsigned char *fileData, int dataSize, int fontSiz
 
 // Generate image font atlas using chars info
 // NOTE: Packing method: 0-Default, 1-Skyline
-#if defined(SUPPORT_FILEFORMAT_TTF)
+#if defined(SUPPORT_FILEFORMAT_TTF) || defined(SUPPORT_FILEFORMAT_BDF)
 Image GenImageFontAtlas(const GlyphInfo *glyphs, Rectangle **glyphRecs, int glyphCount, int fontSize, int padding, int packMethod)
 {
     Image atlas = { 0 };
@@ -2036,18 +2071,21 @@ int GetCodepointPrevious(const char *text, int *codepointSize)
 //----------------------------------------------------------------------------------
 // Module specific Functions Definition
 //----------------------------------------------------------------------------------
-#if defined(SUPPORT_FILEFORMAT_FNT)
+#if defined(SUPPORT_FILEFORMAT_FNT) || defined(SUPPORT_FILEFORMAT_BDF)
 // Read a line from memory
 // REQUIRES: memcpy()
 // NOTE: Returns the number of bytes read
 static int GetLine(const char *origin, char *buffer, int maxLength)
 {
     int count = 0;
-    for (; count < maxLength; count++) if (origin[count] == '\n') break;
+    for (; count < maxLength - 1; count++) if (origin[count] == '\n') break;
     memcpy(buffer, origin, count);
+    buffer[count] = '\0';
     return count;
 }
+#endif
 
+#if defined(SUPPORT_FILEFORMAT_FNT)
 // Load a BMFont file (AngelCode font file)
 // REQUIRES: strstr(), sscanf(), strrchr(), memcpy()
 static Font LoadBMFont(const char *fileName)
@@ -2213,4 +2251,276 @@ static Font LoadBMFont(const char *fileName)
 
 #endif
 
+#if defined(SUPPORT_FILEFORMAT_BDF)
+
+// Convert hexadecimal to decimal (single digit)
+static char HexToInt(char hex) {
+    if (hex >= '0' && hex <= '9')
+    {
+        return hex - '0';
+    }
+    else if (hex >= 'a' && hex <= 'f')
+    {
+        return hex - 'a' + 10;
+    }
+    else if (hex >= 'A' && hex <= 'F')
+    {
+        return hex - 'A' + 10;
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+// Load font data for further use
+// NOTE: Requires BDF font memory data
+static GlyphInfo *LoadBDFFontData(const unsigned char *fileData, int dataSize, int *codepoints, int codepointCount, int* outFontSize)
+{
+    #define MAX_BUFFER_SIZE 256
+    char buffer[MAX_BUFFER_SIZE] = { 0 };
+
+    GlyphInfo *glyphs = NULL;
+
+    bool genFontChars = false;
+
+    int totalReadBytes = 0; // Data bytes read (total)
+    int readBytes = 0;      // Data bytes read (line)
+    int readVars = 0;       // Variables filled by sscanf()
+
+    const char *fileText = (const char*)fileData;
+    const char *fileTextPtr = fileText;
+
+    bool fontMalformed = false; // Is the font malformed
+    bool fontStarted = false;   // Has font started (STARTFONT) 
+    int fontBBw = 0;            // Font base character bounding box width
+    int fontBBh = 0;            // Font base character bounding box height
+    int fontBBxoff0 = 0;        // Font base character bounding box X0 offset
+    int fontBByoff0 = 0;        // Font base character bounding box Y0 offset
+    int fontAscent = 0;         // Font ascent
+
+    bool charStarted = false;           // Has character started (STARTCHAR)
+    bool charBitmapStarted = false;     // Has bitmap data started (BITMAP)
+    int charBitmapNextRow = 0;          // Y position for the next row of bitmap data
+    int charEncoding = -1;              // The unicode value of the character (-1 if not set)
+    int charBBw = 0;                    // Character bounding box width 
+    int charBBh = 0;                    // Character bounding box height
+    int charBBxoff0 = 0;                // Character bounding box X0 offset
+    int charBByoff0 = 0;                // Character bounding box Y0 offset
+    int charDWidthX = 0;                // Character advance X
+    int charDWidthY = 0;                // Character advance Y (unused)
+    GlyphInfo *charGlyphInfo = NULL;    // Pointer to output glyph info (NULL if not set)
+
+    if (fileData == NULL) return glyphs;
+
+    // In case no chars count provided, default to 95
+    codepointCount = (codepointCount > 0)? codepointCount : 95;
+
+    // Fill fontChars in case not provided externally
+    // NOTE: By default we fill glyphCount consecutively, starting at 32 (Space)
+    if (codepoints == NULL)
+    {
+        codepoints = (int *)RL_MALLOC(codepointCount*sizeof(int));
+        for (int i = 0; i < codepointCount; i++) codepoints[i] = i + 32;
+        genFontChars = true;
+    }
+
+    glyphs = (GlyphInfo *)RL_CALLOC(codepointCount, sizeof(GlyphInfo));
+
+    while (totalReadBytes <= dataSize)
+    {
+        readBytes = GetLine(fileTextPtr, buffer, MAX_BUFFER_SIZE);
+        totalReadBytes += (readBytes + 1);
+        fileTextPtr += (readBytes + 1);
+
+        // COMMENT
+        if (strstr(buffer, "COMMENT") != NULL) continue; // Ignore line
+
+        if (charStarted)
+        {
+            // ENDCHAR
+            if (strstr(buffer, "ENDCHAR") != NULL)
+            {
+                charStarted = false;
+                continue;
+            }
+
+            if (charBitmapStarted)
+            {
+                if (charGlyphInfo != NULL) {
+                    int pixelY = charBitmapNextRow++;
+                    if (pixelY >= charGlyphInfo->image.height)
+                    {
+                        break;
+                    }
+                    for (int x = 0; x < readBytes; x++)
+                    {
+                        char byte = HexToInt(buffer[x]);
+                        for (int bitX = 0; bitX < 4; bitX++)
+                        {
+                            int pixelX = ((x * 4) + bitX);
+                            if (pixelX >= charGlyphInfo->image.width)
+                            {
+                                break;
+                            }
+
+                            if ((byte & (8 >> bitX)) > 0)
+                            {
+                                ((unsigned char*)charGlyphInfo->image.data)[(pixelY * charGlyphInfo->image.width) + pixelX] = 255;
+                            }
+                        }
+                    }
+                }
+                continue;
+            }
+
+            // ENCODING
+            if (strstr(buffer, "ENCODING") != NULL)
+            {
+                readVars = sscanf(buffer, "ENCODING %i", &charEncoding);
+                continue;
+            }
+
+            // BBX
+            if (strstr(buffer, "BBX") != NULL)
+            {
+                readVars = sscanf(buffer, "BBX %i %i %i %i", &charBBw, &charBBh, &charBBxoff0, &charBByoff0);
+                continue;
+            }
+
+            // DWIDTH
+            if (strstr(buffer, "DWIDTH") != NULL)
+            {
+                readVars = sscanf(buffer, "DWIDTH %i %i", &charDWidthX, &charDWidthY);
+                continue;
+            }
+
+            // BITMAP
+            if (strstr(buffer, "BITMAP") != NULL)
+            {
+                // Search for glyph index in codepoints
+                charGlyphInfo = NULL;
+                for (int codepointIndex = 0; codepointIndex < codepointCount; codepointIndex++)
+                {
+                    if (codepoints[codepointIndex] == charEncoding)
+                    {
+                        charGlyphInfo = &glyphs[codepointIndex];
+                        break;
+                    }
+                }
+
+                // Init glyph info
+                if (charGlyphInfo != NULL)
+                {
+                    charGlyphInfo->value = charEncoding;
+                    charGlyphInfo->offsetX = charBBxoff0 + fontBByoff0;
+                    charGlyphInfo->offsetY = fontBBh - (charBBh + charBByoff0 + fontBByoff0 + fontAscent);
+                    charGlyphInfo->advanceX = charDWidthX;
+
+                    charGlyphInfo->image.data = RL_CALLOC(charBBw * charBBh, 1);
+                    charGlyphInfo->image.width = charBBw;
+                    charGlyphInfo->image.height = charBBh;
+                    charGlyphInfo->image.mipmaps = 1;
+                    charGlyphInfo->image.format = PIXELFORMAT_UNCOMPRESSED_GRAYSCALE;
+                }
+
+                charBitmapStarted = true;
+                charBitmapNextRow = 0;
+
+                continue;
+            }
+        }
+        else if (fontStarted)
+        {
+            // ENDFONT
+            if (strstr(buffer, "ENDFONT") != NULL)
+            {
+                fontStarted = false;
+                break;
+            }
+
+            // SIZE
+            if (strstr(buffer, "SIZE") != NULL)
+            {
+                if (outFontSize != NULL)
+                {
+                    readVars = sscanf(buffer, "SIZE %i", outFontSize);
+                }
+                continue;
+            }
+
+            // PIXEL_SIZE
+            if (strstr(buffer, "PIXEL_SIZE") != NULL)
+            {
+                if (outFontSize != NULL)
+                {
+                    readVars = sscanf(buffer, "PIXEL_SIZE %i", outFontSize);
+                }
+                continue;
+            }
+
+            // FONTBOUNDINGBOX
+            if (strstr(buffer, "FONTBOUNDINGBOX") != NULL)
+            {
+                readVars = sscanf(buffer, "FONTBOUNDINGBOX %i %i %i %i", &fontBBw, &fontBBh, &fontBBxoff0, &fontBByoff0);
+                continue;
+            }
+
+            // FONT_ASCENT
+            if (strstr(buffer, "FONT_ASCENT") != NULL)
+            {
+                readVars = sscanf(buffer, "FONT_ASCENT %i", &fontAscent);
+                continue;
+            }
+
+            // STARTCHAR
+            if (strstr(buffer, "STARTCHAR") != NULL)
+            {
+                charStarted = true;
+                charEncoding = -1;
+                charGlyphInfo = NULL;
+                charBBw = 0;
+                charBBh = 0;
+                charBBxoff0 = 0;
+                charBByoff0 = 0;
+                charDWidthX = 0;
+                charDWidthY = 0;
+                charGlyphInfo = NULL;
+                charBitmapStarted = false;
+                charBitmapNextRow = 0;
+                continue;
+            }
+        }
+        else
+        {
+            // STARTFONT
+            if (strstr(buffer, "STARTFONT") != NULL)
+            {
+                if (fontStarted)
+                {
+                    fontMalformed = true;
+                    break;
+                }
+                else
+                {
+                    fontStarted = true;
+                    continue;
+                }
+            }
+        }
+    }
+
+    if (genFontChars) RL_FREE(codepoints);
+
+    if (fontMalformed)
+    {
+        RL_FREE(glyphs);
+        glyphs = NULL;
+    }
+
+    return glyphs;
+}
+
+#endif
+
 #endif      // SUPPORT_MODULE_RTEXT