diff -r 05d329adcecc -r d83af80eb09b src/font.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/font.c	Tue Nov 07 21:24:06 2023 +0100
@@ -0,0 +1,90 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ * Copyright 2023 Mike Becker. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "ascension/font.h"
+#include "ascension/context.h"
+#include "ascension/error.h"
+
+static char const *asc_font_filename(enum AscFontStyle style) {
+    // TODO: do not assume we are running from the program dir
+    switch (style) {
+        case ASC_FONT_REGULAR:
+            return "fonts/OpenSans-Regular.ttf";
+        case ASC_FONT_BOLD:
+            return "fonts/OpenSans-Bold.ttf";
+        case ASC_FONT_ITALIC:
+            return "fonts/OpenSans-Italic.ttf";
+        case ASC_FONT_BOLD_ITALIC:
+            return "fonts/OpenSans-BoldItalic.ttf";
+    }
+}
+
+AscFont const *asc_font(enum AscFontStyle style, int size) {
+    for (unsigned int i = 0 ; i < asc_context.fonts_loaded ; i++) {
+        AscFont *font = &asc_context.fonts[i];
+        if (font->size == size && font->style == style) {
+            return font;
+        }
+    }
+
+    if (asc_context.fonts_loaded == ASC_MAX_FONTS) {
+        asc_dprintf("WARNING: Maximum number of fonts reached, wiping cache!");
+        asc_font_cache_clear();
+    }
+
+    unsigned int slot = asc_context.fonts_loaded++;
+    AscFont *font = &asc_context.fonts[slot];
+    font->size = size;
+    font->style = style;
+    font->ptr = TTF_OpenFont(asc_font_filename(style), size);
+    if (font->ptr == NULL) {
+        asc_context.fonts_loaded--;
+        asc_error(TTF_GetError());
+        return NULL;
+    }
+    asc_dprintf("Loaded font size %u, style %u in slot %u", size, style, slot);
+    return font;
+}
+
+void asc_font_cache_clear(void) {
+    asc_dprintf("Fonts in cache that are being unloaded: %u", asc_context.fonts_loaded);
+    while (asc_context.fonts_loaded > 0) {
+        unsigned int i = --asc_context.fonts_loaded;
+        AscFont *font = &asc_context.fonts[i];
+        TTF_CloseFont(font->ptr);
+        font->ptr = NULL;
+    }
+}
+
+AscFont const *asc_font_cache_validate(AscFont const *font) {
+    if (font->ptr) {
+        return font;
+    } else {
+        asc_dprintf("Cache miss for font size %u, style %u", font->size, font->style);
+        return asc_font(font->style, font->size);
+    }
+}