From 7fc0d5367622770593312c4244dff9ccf46e6b03 Mon Sep 17 00:00:00 2001
From: Patrick McDermott <patrick.mcdermott@libiquity.com>
Date: Wed, 17 Jul 2019 18:34:39 -0400
Subject: font_render(): New function

---
diff --git a/src/font.c b/src/font.c
index c198943..c2300b5 100644
--- a/src/font.c
+++ b/src/font.c
@@ -27,6 +27,10 @@
 
 #include <linux/font.h>
 
+#define FONT_H(f)              ((size_t) (f)->desc.height)
+#define FONT_W(f)              ((size_t) (f)->desc.width)
+#define CHAR_PIXEL(f, c, x, y) (((((c) * FONT_H(f)) + (y)) * FONT_W(f)) + (x))
+
 struct font {
 	const struct font_desc desc;
 };
@@ -66,3 +70,27 @@ font_get_height(struct font *font)
 {
 	return font->desc.height;
 }
+
+void
+font_render(struct font *font, png_const_colorp fg, png_const_colorp bg,
+		char ch, png_bytepp rows, int row, int col)
+{
+	size_t y;
+	size_t r;
+	size_t x;
+	size_t c;
+
+	for (y = 0, r = row * FONT_H(font); y < FONT_H(font); ++y, ++r) {
+		for (x = 0, c = col * FONT_W(font); x < FONT_W(font); ++x, ++c){
+			if (CHAR_PIXEL(font, ch, x, y)) {
+				*(&rows[r][c] + 0) = fg->red;
+				*(&rows[r][c] + 1) = fg->green;
+				*(&rows[r][c] + 2) = fg->blue;
+			} else {
+				*(&rows[r][c] + 0) = bg->red;
+				*(&rows[r][c] + 1) = bg->green;
+				*(&rows[r][c] + 2) = bg->blue;
+			}
+		}
+	}
+}
diff --git a/src/font.h b/src/font.h
index 0e22c55..ee3942e 100644
--- a/src/font.h
+++ b/src/font.h
@@ -19,8 +19,8 @@
  * along with fbcon2png.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef FONT_H
-#define FONT_H
+#ifndef FONT_H_
+#define FONT_H_
 
 #include <png.h>
 
@@ -35,4 +35,8 @@ font_get_width(struct font *font) __attribute__((pure));
 int
 font_get_height(struct font *font) __attribute__((pure));
 
-#endif  /* FONT_H */
+void
+font_render(struct font *font, png_const_colorp fg, png_const_colorp bg,
+		char ch, png_bytepp rows, int row, int col);
+
+#endif  /* FONT_H_ */
--
cgit v0.9.1