1 files changed, 146 insertions, 0 deletions
diff --git a/xform.c b/xform.c
new file mode 100644
index 0000000..19001cd
--- /dev/null
+++ b/xform.c
@@ -0,0 +1,146 @@
+/*
+ * Trivial ASCII to C source transformation tool
+ * Public domain
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define H_MAX 32
+#define W_MAX 32
+
+int
+main (int argc, char *argv[])
+{
+	if (argc != 3)
+	{
+		fprintf (stderr, "Usage: %s font_height font_width < input\n", argv[0]);
+		exit (1);
+	}
+
+	char *p;
+	int font_height = strtol (argv[1], &p, 10);
+	if (*p || p == argv[1] || font_height <= 0 || font_height > H_MAX)
+	{
+		fprintf (stderr, "invalid font height\n");
+		exit (1);
+	}
+
+	int bit_width = strtol (argv[2], &p, 10);
+	if (*p || p == argv[2] || bit_width   <= 0 || bit_width   > W_MAX)
+	{
+		fprintf (stderr, "invalid font width\n");
+		exit (1);
+	}
+
+	// Width in pixels to width in bits, rounded up to bytes
+	bit_width = (bit_width + 7) / 8 * 8;
+
+	int c, irow = 0, icol = 0, charw = 0;
+	char row_data[H_MAX * W_MAX] = { 0 };
+
+	printf ("struct\n");
+	printf ("{\n");
+	printf ("\tint width;\n");
+	printf ("\tint advance;\n");
+	printf ("\tint rows[%d];\n", font_height);
+	printf ("}\n");
+	printf ("font_data[] =\n");
+	printf ("{\n");
+
+	while ((c = getchar ()) != EOF)
+	{
+		if (c == '\n')
+		{
+			if (irow == 0)
+			{
+				// We expect a new character definition
+				if (icol != 0)
+				{
+					charw = icol;
+
+					icol = 0;
+					irow++;
+				}
+			}
+			else if (irow < font_height)
+			{
+				// Just checking on consistency
+				if (icol != charw)
+				{
+					fprintf (stderr, "wrong line width\n");
+					exit (1);
+				}
+
+				icol = 0;
+				irow++;
+			}
+			else
+			{
+				// Flushing the character after a newline
+				if (icol != 0)
+				{
+					fprintf (stderr, "character too high\n");
+					exit (1);
+				}
+
+				// Character width, horizontal advance
+				printf ("\t{ %2d, %2d, { ", charw, charw + 1);
+
+				int y, x;
+				for (y = 0; ; )
+				{
+					unsigned bits = 0;
+					for (x = 0; x < charw; x++)
+						bits = (bits << 1) | row_data[y * W_MAX + x];
+					if (charw < bit_width)
+						bits <<= (bit_width - charw);
+
+					printf ("0x%0*x", (bit_width + 3) / 4, bits);
+					if (++y != font_height)
+						printf (", ");
+					else
+						break;
+				}
+
+				printf (" } },\n");
+
+				memset (row_data, 0, sizeof row_data);
+				icol = irow = charw = 0;
+			}
+		}
+		else if (c == '#')
+		{
+			// Comments
+			while ((c = getchar ()) != '\n' && c != EOF)
+				;
+			ungetc ('\n', stdin);
+		}
+		else
+		{
+			if (icol == W_MAX)
+			{
+				fprintf (stderr, "character too wide\n");
+				exit (1);
+			}
+
+			if (c != '0' && c != '1')
+			{
+				fprintf (stderr, "invalid input '%c'\n", c);
+				exit (1);
+			}
+			row_data[irow * W_MAX + icol++] = 1 - (c - '0');
+		}
+	}
+
+	if (icol != 0)
+	{
+		fprintf (stderr, "unexpected EOF\n");
+		exit (1);
+	}
+
+	printf ("};\n");
+	return 0;
+}
+