add font loading and rendering to daguerre

1 files changed, 45 insertions, 0 deletions

diff --git a/libraries/daguerre/source/daguerre.cpp b/libraries/daguerre/source/daguerre.cpp
index 7c13a88..2f7fe4d 100644
--- a/libraries/daguerre/source/daguerre.cpp
+++ b/libraries/daguerre/source/daguerre.cpp
@@ -26,6 +26,7 @@ namespace daguerre {
     return n;
   }
 
+  //only supports p6 format
   bool try_load_ppm(std::FILE *input, image<rgb24> &into) {
 
     char header[3];
@@ -62,4 +63,48 @@ namespace daguerre {
 
   }
 
+  //assumes the font is in psf2 format, and has a unicode table
+  bool try_load_psf(std::FILE *input, fixed_bitmap_font<bool> &into) {
+
+    uint32_t header[8];
+    if (std::fread(header, 4, 8, input) != 8)
+      return false;
+
+    const uint32_t glyphs_start = header[2];
+    const uint32_t glyph_count = header[4];
+    const uint32_t glyph_length = header[5];
+    into.height = header[6];
+    into.width = header[7];
+
+    const uint32_t unicode_start = glyphs_start + glyph_count * glyph_length;
+    std::fseek(input, unicode_start, SEEK_SET);
+
+    uint32_t indices[128];
+
+    for (uint32_t index = 0; index < glyph_count; ++index) {
+      uint8_t ch;
+      std::fread(&ch, 1, 1, input);
+      if (ch < 128)
+        indices[ch] = index;
+      do
+        std::fread(&ch, 1, 1, input);
+      while (ch != 0xff);
+    }
+
+    for (uint8_t ch = 0; ch < 128; ++ch) {
+      std::fseek(input, glyphs_start + glyph_length * indices[ch], SEEK_SET);
+      into.glyphs[ch] = image<bool>(into.width, into.height);
+      for (unsigned h = 0; h < into.height; ++h)
+        for (unsigned wb = 0; wb < into.width; wb += 8) {
+          uint8_t byte;
+          std::fread(&byte, 1, 1, input);
+          for (unsigned x = 0; x < 8 && wb + x < into.width; ++x)
+            into.glyphs[ch].set(wb + x, h, (byte >> (7 - x)) & 1);
+        }
+    }
+
+    return true;
+
+  }
+
 }