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GRRLIB 4.2.X Freetype support

In this post i have add information how to add freetype library support to the GRRLIB 4.2.X library

GRRLIB_free_print.h

void GRRLIB_InitFreetype();

void GRRLIB_initTexture(void);

void GRRLIB_Printf2(	int x, 
							int y, 
							const char *string, 
							unsigned int fontSize, 
							int color); 

GRRLIB_texImg* GRRLIB_GetTexture(void);

GRRLIB_free_print.c

#include <malloc.h>
#include <stdarg.h>
#include <stdio.h>

#include <grrlib.h>

#include <ft2build.h> /* I presume you have freetype for the Wii installed */
#include FT_FREETYPE_H

#include "font_ttf.h"

static FT_Library ftLibrary;
static FT_Face ftFace;

void *fontTempLayer=NULL;
void *fontTexture=NULL;
GRRLIB_texImg image;

extern  Mtx                  GXmodelView2D;

/* Static function prototypes */
static void BitmapTo4x4RGBA(const unsigned char *src, void *dst, const unsigned int width, const unsigned int height);
static bool BlitGlyph(FT_Bitmap *bitmap, int offset, int top, int color) ;

void GRRLIB_InitFreetype(void) 
{
	unsigned int error = FT_Init_FreeType(&ftLibrary);
	if (error) 
	{
		exit(0);
	}

	error = FT_New_Memory_Face(ftLibrary, font_ttf, font_ttf_size, 0, &ftFace);
	if (error == FT_Err_Unknown_File_Format) 
	{
		exit(0);
	} 
	else if (error) 
	{
		/* Some other error */
		exit(0);
	}
}

void GRRLIB_initTexture(void)
{
   // Clear previous video frame buffer
   if (fontTexture!=NULL) free(fontTexture);

   fontTempLayer = (void*) calloc(1, 640 * 528 * 4);

   if (fontTempLayer == NULL) 
   {
	  /* Oops! Something went wrong! */
	  exit(0);
   }
}

void GRRLIB_Printf2(int x, int y, const char *string, unsigned int fontSize, int color) 
{
	unsigned int error = 0;
	int penX = 0;
	int penY = fontSize;
	FT_GlyphSlot slot = ftFace->glyph;
	FT_UInt glyphIndex = 0;
	FT_UInt previousGlyph = 0;
	FT_Bool hasKerning = FT_HAS_KERNING(ftFace);

    error = FT_Set_Pixel_Sizes(ftFace, 0, fontSize);
	if (error) 
	{
		/* Failed to set the font size to the requested size. 
		 * You probably should set a default size or something. 
		 * I'll leave that up to the reader. */
		 FT_Set_Pixel_Sizes(ftFace, 0, 12);
	}
	
	/* Convert the string to UTF32 */
	size_t length = strlen(string);
	wchar_t *utf32 = (wchar_t*)malloc(length * sizeof(wchar_t)); 
	length = mbstowcs(utf32, string, length);
	
	/* Loop over each character, drawing it on to the 4, until the 
	 * end of the string is reached, or until the pixel width is too wide */
	unsigned int loop = 0;
	for (loop = 0; loop < length; ++loop)
    {
		glyphIndex = FT_Get_Char_Index(ftFace, utf32[ loop ]);
		
		/* To the best of my knowledge, none of the other freetype 
		 * implementations use kerning, so my method ends up looking
		 * slightly better 🙂 */
		if (hasKerning && previousGlyph && glyphIndex) 
		{
			FT_Vector delta;
			FT_Get_Kerning(ftFace, previousGlyph, glyphIndex, FT_KERNING_DEFAULT, &delta);
			penX += delta.x >> 6;
		}
	
		error = FT_Load_Glyph(ftFace, glyphIndex, FT_LOAD_RENDER);
		if (error)
        {
			/* Whoops, something went wrong trying to load the glyph 
			 * for this character... you should handle this better */
			continue;
		}
	
		if (BlitGlyph(&slot->bitmap, penX + slot->bitmap_left+x, penY - slot->bitmap_top+y, color) == true) 
		{
			/* The glyph was successfully blitted to the buffer, move the pen forwards */
			penX += slot->advance.x >> 6;
			previousGlyph = glyphIndex;
		} 
		else 
		{
			/* BlitGlyph returned false, the line must be full */
			free(utf32);
			return;
		}
	}

	free(utf32);
}

/* Returns true if the character was draw on to the buffer, false if otherwise */
bool BlitGlyph(FT_Bitmap *bitmap, int offset, int top, int color) 
{
	int bitmapWidth = bitmap->width;
	int bitmapHeight = bitmap->rows;

	if (offset + bitmapWidth > 640) 
	{
		/* Drawing this character would over run the buffer, so don't draw it */
		return false;
	}

	/* Draw the glyph onto the buffer, blitting from the bottom up */
	/* CREDIT: Derived from a function by DragonMinded */
	unsigned char *p = fontTempLayer;
	unsigned int y = 0;
	for (y = 0; y < bitmapHeight; ++y) 
	{
		int sywidth = y * bitmapWidth;
		int dywidth = (y + top) * 640;

		unsigned int column = 0;
		for (column = 0; column < bitmapWidth; ++column)
        {
			unsigned int srcloc = column + sywidth;
			unsigned int dstloc = ((column + offset) + dywidth) << 2;
			
			/* Copy the alpha value for this pixel into the texture buffer */
			p[ dstloc + 0 ] = (color & 0xff);
			p[ dstloc + 1 ] = ((color >> 8) & 0xff);
			p[ dstloc + 2 ] = ((color >> 16) & 0xff);
			p[ dstloc + 3 ] = (bitmap->buffer[ srcloc ]);
		}
	}
	
	return true;
}

/* Render the text string to a 4x4RGBA texture, return a pointer to this texture */
GRRLIB_texImg* GRRLIB_GetTexture(void) 
{
	/* Create a new buffer, this time to hold the final texture 
	 * in a format suitable for the Wii */
	fontTexture = memalign(32, 640 * 528 * 4);

	/* Convert the RGBA temp buffer to a format usuable by GX */
	BitmapTo4x4RGBA(fontTempLayer, fontTexture, 640, 528);
	DCFlushRange(fontTexture, 640 * 528 * 4);

	/* The temp buffer is no longer required */
	free(fontTempLayer);
	image.data=fontTexture;
	image.w=640;
	image.h=528;
	
	return &image;
}

void BitmapTo4x4RGBA(const unsigned char *src, void *dst, const unsigned int width, const unsigned int height)
{
	unsigned int block = 0;
	unsigned int i = 0;
	unsigned int c = 0;
	unsigned int ar = 0;
	unsigned int gb = 0;
	unsigned char *p = (unsigned char*)dst;

	for (block = 0; block < height; block += 4) {
		for (i = 0; i < width; i += 4) {
			/* Alpha and Red */
			for (c = 0; c < 4; ++c) {
				for (ar = 0; ar < 4; ++ar) {
					/* Alpha pixels */
					*p++ = src[(((i + ar) + ((block + c) * width)) * 4) + 3];
					/* Red pixels */	
					*p++ = src[((i + ar) + ((block + c) * width)) * 4];
				}
			}
			
			/* Green and Blue */
			for (c = 0; c < 4; ++c) {
				for (gb = 0; gb < 4; ++gb) {
					/* Green pixels */
					*p++ = src[(((i + gb) + ((block + c) * width)) * 4) + 1];
					/* Blue pixels */
					*p++ = src[(((i + gb) + ((block + c) * width)) * 4) + 2];
				}
			}
		} /* i */
	} /* block */
}

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