2 files changed, 70 insertions, 0 deletions

diff --git a/teensy/teensy.h b/teensy/teensy.h
index 1f082f9..0b7829c 100644
--- a/teensy/teensy.h
+++ b/teensy/teensy.h
@@ -1,6 +1,8 @@
 #ifndef TEENSY_H_
 #define TEENSY_H_
 
+#include <limits.h>
+
 #include "teensy_common.h"
 #include "teensy_context.h"
 #include "teensy_list.h"
@@ -68,6 +70,10 @@ struct ty_image {
     int height;
 };
 
+struct ty_font {
+    struct ty_image glyphs[CHAR_MAX];
+};
+
 struct ty_renderer {
     struct ty_image screen;
 };
@@ -92,6 +98,9 @@ void ty_img_set_pixel(
     struct ty_color color
 );
 
+void ty_font_add_glyph(struct ty_font *font, uint8_t c, struct ty_image img);
+int ty_font_width(struct ty_font *font, const char *fmt, ...);
+
 void ty_draw_clear(struct ty_color col);
 void ty_draw_image(struct ty_image img, struct ty_vec2i pos);
 void ty_draw_image_ex(
@@ -105,6 +114,13 @@ void ty_draw_line(
     struct ty_vec2i end,
     struct ty_color color
 );
+void ty_draw_text(struct ty_font *font, struct ty_vec2i pos, const char *text);
+void ty_draw_text_fmt(
+    struct ty_font *font,
+    struct ty_vec2i pos,
+    const char *fmt,
+    ...
+);
 void ty_draw_end(void);
 
 void ty_sleep(uint64_t ms);
diff --git a/teensy/teensy_renderer.c b/teensy/teensy_renderer.c
index b29e485..b51d2a9 100644
--- a/teensy/teensy_renderer.c
+++ b/teensy/teensy_renderer.c
@@ -3,6 +3,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <math.h>
+#include <stdarg.h>
 
 #include "teensy_context.h"
 #include "teensy_list.h"
@@ -91,6 +92,31 @@ void ty_img_set_pixel(
     img.data[pos.y * img.width + pos.x] = color;
 }
 
+// This function technically is not needed, but I may want unicode support in
+// the future, when an abstraction like this is needed.
+void ty_font_add_glyph(struct ty_font *font, uint8_t c, struct ty_image img)
+{
+    font->glyphs[c] = img;
+}
+
+int ty_font_width(struct ty_font *font, const char *fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    int len = vsnprintf(NULL, 0, fmt, args);
+    char *text = ty_talloc(sizeof(char) * (len + 1));
+    va_end(args);
+
+    va_start(args, fmt);
+    vsnprintf(text, len + 1, fmt, args);
+    va_end(args);
+
+    int width = 0;
+    for (uint8_t *c = (uint8_t*)text; *c != '\0'; c++)
+        width += font->glyphs[*c].width;
+    return width;
+}
+
 void ty_draw_clear(struct ty_color col)
 {
     assert(is_renderer_init());
@@ -211,6 +237,34 @@ void ty_draw_line(
     }
 }
 
+void ty_draw_text(struct ty_font *font, struct ty_vec2i pos, const char *text)
+{
+    for (const uint8_t *c = (const uint8_t*)text; *c != '\0'; c++) {
+        struct ty_image glyph = font->glyphs[*c];
+        ty_draw_image(glyph, pos);
+        pos.x += glyph.width;
+    }
+}
+
+void ty_draw_text_fmt(
+    struct ty_font *font,
+    struct ty_vec2i pos,
+    const char *fmt,
+    ...
+) {
+    va_list args;
+    va_start(args, fmt);
+    int len = vsnprintf(NULL, 0, fmt, args);
+    char *text = ty_talloc(sizeof(char) * (len + 1));
+    va_end(args);
+
+    va_start(args, fmt);
+    vsnprintf(text, len + 1, fmt, args);
+    va_end(args);
+
+    ty_draw_text(font, pos, text);
+}
+
 void ty_draw_end(void)
 {
     assert(is_renderer_init());