started text rendering

1 files changed, 71 insertions, 0 deletions

diff --git a/text.c b/text.c
new file mode 100644
index 0000000..19d62a2
--- /dev/null
+++ b/text.c
@@ -0,0 +1,71 @@
+#include "base.h"
+no_warn_start
+#include "stb_truetype.h"
+no_warn_end
+#include <stdarg.h>
+#include <stdlib.h>
+
+typedef struct {
+	float char_height;
+	u32 nchars;
+	GLuint texture;
+	stbtt_bakedchar chars[];
+} Font;
+
+static char text_err[200];
+static void text_clear_err(void) {
+	text_err[0] = '\0';
+}
+static void text_set_err(char const *fmt, ...) {
+	va_list args;
+	va_start(args, fmt);
+	vsnprintf(text_err, sizeof text_err - 1, fmt, args);
+	va_end(args);
+}
+
+static bool text_has_err(void) {
+	return text_err[0] != '\0';
+}
+
+char const *text_get_err(void) {
+	return text_err;
+}
+
+Font *text_font_load(char const *ttf_filename, float font_size) {
+	Font *font = NULL;
+	u32 nchars = 128;
+	FILE *ttf_file = fopen(ttf_filename, "rb");
+	
+	text_clear_err();
+
+	if (ttf_file) {
+		fseek(ttf_file, 0, SEEK_END);
+		u32 file_size = (u32)ftell(ttf_file);
+		if (file_size < (50UL<<20)) { // fonts aren't usually bigger than 50 MB
+			char *file_data = calloc(1, file_size);
+			Font *font = calloc(1, sizeof *font + nchars * sizeof *font->chars);
+			if (file_data && font) {
+				font->nchars = nchars;
+				font->char_height = font_size;
+				stbtt_
+			} else {
+				text_set_err("Not enough memory for font.");
+			}
+			free(file_data);
+			if (text_has_err())
+				free(font);
+			fclose(ttf_file);
+		} else {
+			text_set_err("Font file too big (%u megabytes).", (uint)(file_size >> 20));
+		}
+	} else {
+		text_set_err("Couldn't open font file: %s.", ttf_filename);
+	}
+	return NULL;
+}
+
+void text_render(Font *font, char const *text, float x, float y) {
+}
+
+void text_get_size(Font *font, char const *text, float *width, float *height) {
+}