refactor!: clean up font caching system

Reworked font caching system to load all data for a set font size at once. `font->letters` is now a 2D array, with the first value being the size, and the second value being a `char` value. `xpd_font_cache` is no longer called twice for every character drawn. BREAKING CHANGE: While this shouldn't affect users, the internal functions `xpd_font_get_metrics` and `xpd_font_get_texture` have been removed. Various types were also changed, with `xpd_font_cache_t` being removed altogether.
slimit75 · Apr 9, 2024 · 19f2742 · 19f2742
1 parent 95cdb35
commit 19f2742
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Showing 2 changed files with 28 additions and 84 deletions.
diff --git a/src/fonts.c b/src/fonts.c
@@ -1,122 +1,82 @@
 #include "xpdraw/fonts.h"
 
 #include <assert.h>
-#include <stdbool.h>
-#include <XPLMUtilities.h>
 
-bool fonts_init = false;
-char str[255];
+int fonts_init = 0;
 FT_Library ft;
 
 void xpd_font_load(xpd_font_face_t *font, const char *path) {
-	if (fonts_init == false) {
+	if (fonts_init == 0) {
 		FT_Init_FreeType(&ft);
-		fonts_init = true;
+		fonts_init = 1;
 	}
 
 	FT_New_Face(ft, path, 0, &font->ftFace);
 	font->letters_idx = -1;
 }
 
-void xpd_font_cache(xpd_font_face_t *font, int size, char letter) {
-	// TODO: Does this need to be called as often as it currently is?
-	bool not_loaded = true;
-
+void xpd_font_cache(xpd_font_face_t *font, int size) {
+	// Throw a fatal error if the font isn't properly loaded
 	if (font->ftFace == NULL) {
 		assert("font->ftFace == NULL");
 	}
 
-	for (int i = 0; (i < XPD_CHAR_MAX) && (i <= font->letters_idx); i++) {
-		if (font->letters[i].size == size && font->letters[i].letter == letter) {
-			not_loaded = false;
-			break;
-		}
-	}
-
-	if (not_loaded == true) {
-		FT_Set_Pixel_Sizes(font->ftFace, 0, (int)(size * 1.5));
-		FT_Load_Char(font->ftFace, letter, FT_LOAD_RENDER);
-
-		font->letters_idx++;
-		font->letters[font->letters_idx].size         = size;
-		font->letters[font->letters_idx].letter       = letter;
-		font->letters[font->letters_idx].data.metrics = font->ftFace->glyph->metrics;
-
-		xpd_load_buffer(&font->letters[font->letters_idx].data.bitmap, font->ftFace->glyph->bitmap.buffer,
-						font->ftFace->glyph->bitmap.width, font->ftFace->glyph->bitmap.rows, GL_ALPHA);
-	}
-}
-
-FT_Glyph_Metrics xpd_font_get_metrics(xpd_font_face_t *font, int size, char letter) {
-	xpd_font_cache(font, size, letter); // Automatically cache char if it isn't already cached
-
-	for (int i = 0; i < CHAR_MAX; i++) {
-		if (font->letters[i].size == size && font->letters[i].letter == letter) {
-			return font->letters[i].data.metrics;
-		}
-	}
+	if (font->letters[size][7].letter == 0u) {
+		// Tell FreeType what font size we want
+		FT_Set_Pixel_Sizes(font->ftFace, 0, (int) (size * 1.5));
 
-	sprintf(str, "xpdraw: Unable to load metrics for font family %s at letter %c & size %i!\n",
-			font->ftFace->family_name, letter, size);
-	XPLMDebugString(str);
-	return xpd_metrics_empty;
-}
+		// Load data for each available character
+		for (int i = CHAR_MIN; i <= CHAR_MAX; i++) {
+			FT_Load_Char(font->ftFace, i, FT_LOAD_RENDER);
 
-xpd_texture_t xpd_font_get_texture(xpd_font_face_t *font, int size, char letter) {
-	xpd_font_cache(font, size, letter); // Automatically cache char if it isn't already cached
+			font->letters[size][i].letter = i;
+			font->letters[size][i].metrics = font->ftFace->glyph->metrics;
 
-	for (int i = 0; i < CHAR_MAX; i++) {
-		if (font->letters[i].size == size && font->letters[i].letter == letter) {
-			return font->letters[i].data.bitmap;
+			xpd_load_buffer(&font->letters[size][i].bitmap, font->ftFace->glyph->bitmap.buffer,
+			                font->ftFace->glyph->bitmap.width, font->ftFace->glyph->bitmap.rows, GL_ALPHA);
 		}
 	}
-
-	sprintf(str, "xpdraw: Unable to load texture for font family %s at letter %c & size %i!\n",
-			font->ftFace->family_name, letter, size);
-	XPLMDebugString(str);
-	return xpd_texture_empty;
 }
 
 int xpd_text_length(xpd_font_face_t *font, const char *text, const int size) {
 	int width = 0;
 
 	// Calculate the length of the string before drawing it
 	for (int i = 0; i < strlen(text); i++) {
-		FT_Glyph_Metrics text_metrics = xpd_font_get_metrics(font, size, text[i]);
+		FT_Glyph_Metrics text_metrics = font->letters[size][text[i]].metrics;
 		if (i == strlen(text) - 1) {
-			width += (int)((text_metrics.width + text_metrics.horiBearingX) / 64);
-		}
-		else {
-			width += (int)(text_metrics.horiAdvance / 64);
+			width += (int) ((text_metrics.width + text_metrics.horiBearingX) / 64);
+		} else {
+			width += (int) (text_metrics.horiAdvance / 64);
 		}
 	}
 
 	return width;
 }
 
 void xpd_text_draw(xpd_font_face_t *font, const char *text, int x, int y, int size, xpd_text_align_t align,
-				   xpd_color_t textColor) {
+                   xpd_color_t textColor) {
+	xpd_font_cache(font, size);
 	glColor4f(textColor.red, textColor.green, textColor.blue, textColor.alpha);
 
 	// Handle text alignment
 	if (align == xpdAlignCenter) {
 		x -= xpd_text_length(font, text, size) / 2;
-	}
-	else if (align == xpdAlignRight) {
+	} else if (align == xpdAlignRight) {
 		x -= xpd_text_length(font, text, size);
 	}
 
 	// Draw each character
 	for (int i = 0; i < strlen(text); i++) {
-		FT_Glyph_Metrics text_metrics = xpd_font_get_metrics(font, size, text[i]);
+		FT_Glyph_Metrics text_metrics = font->letters[size][text[i]].metrics;
 
 		// Calculate offset from the passed y value
 		int y_offset = (text_metrics.horiBearingY / 64) - (text_metrics.height / 64);
 
 		// Fetch & draw texture
-		xpd_texture_t image = xpd_font_get_texture(font, size, text[i]);
+		xpd_texture_t image = font->letters[size][text[i]].bitmap;
 		xpd_draw_texture(&image, x + (text_metrics.horiBearingX / 64), y + y_offset, image.width, image.height,
-						 textColor);
+		                 textColor);
 
 		// Advance to the next character
 		x += text_metrics.horiAdvance / 64;

diff --git a/src/xpdraw/fonts.h b/src/xpdraw/fonts.h
@@ -36,33 +36,17 @@ typedef enum {
 } xpd_text_align_t;
 
 typedef struct {
+	char letter;
 	FT_Glyph_Metrics metrics;
 	xpd_texture_t bitmap;
-} xpd_font_cache_t;
-
-typedef struct {
-	int size;
-	char letter;
-	xpd_font_cache_t data;
 } xpd_font_letter_t;
 
 typedef struct {
 	FT_Face ftFace;
-	xpd_font_letter_t letters[XPD_CHAR_MAX];
+	xpd_font_letter_t letters[255][XPD_CHAR_MAX];
 	int letters_idx;
 } xpd_font_face_t;
 
-static const FT_Glyph_Metrics xpd_metrics_empty = {
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0,
-	0
-};
-
 /**
  * @brief Load a new font
  *
@@ -93,7 +77,7 @@ int xpd_text_length(xpd_font_face_t *font, const char *text, int size);
  * @param color Color of the text; defaults to white
  */
 void xpd_text_draw(xpd_font_face_t *font, const char *text, int x, int y, int size, xpd_text_align_t align,
-				   xpd_color_t color);
+                   xpd_color_t color);
 
 #ifdef __cplusplus
 }