Add basic text rendering

src/print.c

@@ -0,0 +1,39 @@
+#include "print.h"
+#include "ltp1245.h"
+
+static uint8_t Print_Buffer[64 * LTP1245_LINE_BYTES];
+
+void Print_Text(const char *text, const Font_t *font)
+{
+    int height = font->height;
+    memset(Print_Buffer, 0, LTP1245_LINE_BYTES * height);
+    char c;
+    int xpos = 0;
+    while((c = *text++) != 0)
+    {
+        if(c > font->glyphcount + font->charoffset
+            || c < font->charoffset)
+        {
+            continue;
+        }
+
+        int width = font->glyphs[c - font->charoffset].width;
+        const uint8_t *bitmap = font->glyphs[c - font->charoffset].bitmap;
+
+        for(int i = 0; i < width * height; i++)
+        {
+            int x = i / height + xpos;
+            int y = i % height;
+            if(bitmap[i / 8] & (0x80 >> (i % 8)))
+            {
+                // Pixel is black
+                Print_Buffer[y * LTP1245_LINE_BYTES + x / 8] |=
+                    0x80 >> (x % 8);
+            }
+        }
+
+        xpos += width;
+    }
+
+    LTP1245_Print(Print_Buffer, height);
+}