src/rawfont.c

   1 #include <cairo.h>
   2 #include <stdio.h>
   3 #include <math.h>
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #define SURFACE_WIDTH (256)
   9 #define SURFACE_HEIGHT (SURFACE_WIDTH)
  10
  11 #define CHAR_START ' '
  12 #define CHAR_END ('~' + 2)
  13
  14 void GenerateFontFiles (char const * szFilePrefix, char const * szFontname, int nPoints, bool boItalic, bool boBold, bool boAntialiase);
  15
  16 int main (int argc, char *argv[])
  17 {
  18         GenerateFontFiles ("font01", "sans", 12, false, false, true);
  19         GenerateFontFiles ("font02", "sans", 20, false, false, true);
  20
  21         return 0;
  22 }
  23
  24 // "serif", "sans-serif", "cursive", "fantasy", "monospace"
  25 void GenerateFontFiles (char const * szFilePrefix, char const * szFontname, int nPoints, bool boItalic, bool boBold, bool boAntialiase) {
  26         unsigned char cCharacter;
  27         float fXPos;
  28         float fYPos;
  29         float fMaxHeight;
  30         char szPrint[2];
  31         int nPos;
  32         float fArea;
  33         float fDimension;
  34         int nDimension;
  35         float fPower;
  36         int nPower;
  37         FILE * fhPositions;
  38         FILE * fhData;
  39         cairo_font_options_t * psFontOptions;
  40         char szAll[(CHAR_END - CHAR_START + 1)];
  41         float fDescent;
  42         cairo_format_t eFormat = CAIRO_FORMAT_ARGB32;
  43         unsigned char * pucData;
  44         unsigned char ucAlpha;
  45         unsigned char ucColour;
  46         float fScaled;
  47         cairo_font_slant_t eSlant;
  48         cairo_font_weight_t eWeight;
  49         char * szFilename;
  50         int nPrefixLen;
  51
  52         nPrefixLen = strlen (szFilePrefix);
  53         szFilename = (char *)malloc (nPrefixLen + 5);
  54         strncpy (szFilename, szFilePrefix, nPrefixLen);
  55
  56         eSlant = (boItalic ? CAIRO_FONT_SLANT_ITALIC : CAIRO_FONT_SLANT_NORMAL);
  57         eWeight = (boBold ? CAIRO_FONT_WEIGHT_BOLD : CAIRO_FONT_WEIGHT_NORMAL);
  58
  59         // Establish the texture size needed
  60         cairo_surface_t * psSurface = cairo_image_surface_create (eFormat, SURFACE_WIDTH, SURFACE_HEIGHT);
  61         cairo_t * psContext = cairo_create (psSurface);
  62         cairo_text_extents_t sExtents;
  63         cairo_font_extents_t sFontExtents;
  64
  65         // "serif", "sans-serif", "cursive", "fantasy", "monospace"
  66         cairo_select_font_face (psContext, szFontname, eSlant, eWeight);
  67         cairo_set_font_size (psContext, nPoints);
  68         cairo_set_source_rgb (psContext, 1.0, 1.0, 0.0);
  69
  70         if (!boAntialiase) {
  71                 psFontOptions = cairo_font_options_create ();
  72                 // CAIRO_ANTIALIAS_BEST
  73                 // CAIRO_ANTIALIAS_NONE
  74                 cairo_font_options_set_antialias (psFontOptions, CAIRO_ANTIALIAS_NONE);
  75                 //cairo_set_font_options (psContext, psFontOptions);
  76                 cairo_font_options_destroy (psFontOptions);
  77         }
  78
  79         for (cCharacter = 0; cCharacter < (CHAR_END - CHAR_START); cCharacter++) {
  80                 szAll[cCharacter] = cCharacter + CHAR_START;
  81         }
  82         szAll[cCharacter] = 0;
  83         cairo_text_extents (psContext, szAll, & sExtents);
  84         fArea = sExtents.height * sExtents.width;
  85
  86         cairo_font_extents (psContext, & sFontExtents);
  87         fMaxHeight = sFontExtents.height;
  88         fDescent = sFontExtents.descent;
  89
  90         printf ("Max width:  %f\n", sFontExtents.max_x_advance);
  91         printf ("Max height: %f\n", fMaxHeight);
  92
  93         fDimension = sqrt (fArea);
  94         nDimension = (fDimension + 1.0f);
  95         fPower = ceil (log (fDimension) / log (2.0));
  96         nPower = (fPower + 0.5f);
  97         //printf ("Power: %d\n", nPower);
  98         nDimension = pow (2, nPower);
  99         printf ("Dimension: %d x %d\n", nDimension, nDimension);
 100
 101         cairo_destroy (psContext);
 102         cairo_surface_destroy (psSurface);
 103
 104
 105
 106         // Recrease the surface but this time with a suitable size
 107         psSurface = cairo_image_surface_create (eFormat, nDimension, nDimension);
 108         psContext = cairo_create (psSurface);
 109
 110         cairo_select_font_face (psContext, szFontname, eSlant, eWeight);
 111         cairo_set_font_size (psContext, nPoints);
 112         cairo_set_source_rgb (psContext, 1.0, 1.0, 1.0);
 113
 114         if (!boAntialiase) {
 115                 psFontOptions = cairo_font_options_create ();
 116                 cairo_font_options_set_antialias (psFontOptions, CAIRO_ANTIALIAS_NONE);
 117                 //cairo_set_font_options (psContext, psFontOptions);
 118                 cairo_font_options_destroy (psFontOptions);
 119         }
 120
 121         // Open the CSV file for the character details
 122         strncpy (szFilename + nPrefixLen, ".csv", 5);
 123         fhPositions = fopen (szFilename, "w");
 124
 125         // Render the characters to the texture
 126         szPrint[1] = 0;
 127         fXPos = 0.0f;
 128         fYPos = fMaxHeight;
 129         for (cCharacter = CHAR_START; cCharacter < CHAR_END; cCharacter++) {
 130                 szPrint[0] = cCharacter;
 131                 cairo_text_extents (psContext, szPrint, & sExtents);
 132                 if ((fXPos + sExtents.x_advance) > nDimension) {
 133                         fXPos = 0.0f;
 134                         fYPos += fMaxHeight;
 135                 }
 136
 137                 cairo_move_to (psContext, fXPos, fYPos - fDescent);
 138                 cairo_show_text (psContext, szPrint);
 139
 140                 fprintf (fhPositions, "%d, %d, %d, %d\n", (int)fXPos, (int)(fYPos - fMaxHeight), (int)sExtents.x_advance, (int)fMaxHeight);
 141
 142                 fXPos += sExtents.x_advance;
 143                 fYPos += sExtents.y_advance;
 144         }
 145
 146
 147         close (fhPositions);
 148
 149         //cairo_text_extents (psContext, "Hello, world ", & sExtents);
 150         //printf ("X bearing: %f\n", sExtents.x_bearing);
 151         //printf ("Y bearing: %f\n", sExtents.y_bearing);
 152         //printf ("Width: %f\n", sExtents.width);
 153         //printf ("Height: %f\n", sExtents.height);
 154         //printf ("X advance: %f\n", sExtents.x_advance);
 155         //printf ("Y advance: %f\n", sExtents.y_advance);
 156
 157         cairo_surface_flush (psSurface);
 158
 159         // Output the texture as raw
 160         pucData = cairo_image_surface_get_data (psSurface);
 161         strncpy (szFilename + nPrefixLen, ".raw", 5);
 162         fhData = fopen (szFilename, "wb");
 163         for (nPos = 0; nPos < (nDimension * nDimension); nPos++) {
 164                 ucAlpha = pucData[(nPos * 4) + 3];
 165
 166                 if (ucAlpha == 0u) {
 167                         fputc (0u, fhData);
 168                         fputc (0u, fhData);
 169                         fputc (0u, fhData);
 170                         fputc (0u, fhData);
 171                 }
 172                 else {
 173                         // Convert 'pre-multiplied alpha' to 'post-multiplied alpha'
 174
 175                         // Red
 176                         ucColour = pucData[(nPos * 4) + 2];
 177                         fScaled = round (((float)ucColour) / (((float)ucAlpha) / 255.0f));
 178                         //printf ("R: %f, %u, %u\n", fScaled, ucColour, ucAlpha);
 179                         fputc (((unsigned char)fScaled), fhData);
 180
 181                         // Green
 182                         ucColour = pucData[(nPos * 4) + 1];
 183                         fScaled = round (((float)ucColour) / (((float)ucAlpha) / 255.0f));
 184                         //printf ("G: %f, %u, %u\n", fScaled, ucColour, ucAlpha);
 185                         fputc (((unsigned char)fScaled), fhData);
 186
 187                         // Blue
 188                         ucColour = pucData[(nPos * 4) + 0];
 189                         fScaled = round (((float)ucColour) / (((float)ucAlpha) / 255.0f));
 190                         //printf ("B: %f, %u, %u\n", fScaled, ucColour, ucAlpha);
 191                         fputc (((unsigned char)fScaled), fhData);
 192
 193                         fputc (ucAlpha, fhData);
 194                 }
 195         }
 196         close (fhData);
 197
 198         // Output the texture as a PNG
 199         cairo_destroy (psContext);
 200         strncpy (szFilename + nPrefixLen, ".png", 5);
 201         cairo_surface_write_to_png (psSurface, szFilename);
 202         cairo_surface_destroy (psSurface);
 203 }
 204
 205