refactor: enhance loadAsciiFont function with promise support and err…

…or handling
humanbydefinition · Dec 15, 2024 · 643e6ea · 643e6ea
1 parent d2d6160
commit 643e6ea
Showing 1 changed file with 65 additions and 55 deletions.
diff --git a/src/index.js b/src/index.js
@@ -68,69 +68,79 @@ p5.prototype.registerMethod("beforePreload", p5.prototype.preloadAsciiFont);
  * loadAsciiFont('path/to/font.ttf');
  */
 p5.prototype.loadAsciiFont = function (font) {
-    const setFont = async (loadedFont, fontPath) => {
-        p5asciify.font = loadedFont;
-
-        try { // Convert the font to Base64 for use in the text-based ASCII renderer
-            const response = await fetch(fontPath);
-            const arrayBuffer = await response.arrayBuffer();
-            const base64String = btoa(
-                new Uint8Array(arrayBuffer)
-                    .reduce((data, byte) => data + String.fromCharCode(byte), '')
-            );
+    return new Promise((resolve, reject) => {
+        const setFont = async (loadedFont, fontPath) => {
+            p5asciify.font = loadedFont;
 
-            // Determine the font type based on the file extension
-            let mimeType = '';
-            if (fontPath.toLowerCase().endsWith('.ttf')) {
-                mimeType = 'truetype';
-            } else if (fontPath.toLowerCase().endsWith('.otf')) {
-                mimeType = 'opentype';
-            } else {
-                mimeType = 'truetype';
+            try { 
+                const response = await fetch(fontPath);
+                const arrayBuffer = await response.arrayBuffer();
+                const base64String = btoa(
+                    new Uint8Array(arrayBuffer)
+                        .reduce((data, byte) => data + String.fromCharCode(byte), '')
+                );
+
+                let mimeType = '';
+                if (fontPath.toLowerCase().endsWith('.ttf')) {
+                    mimeType = 'truetype';
+                } else if (fontPath.toLowerCase().endsWith('.otf')) {
+                    mimeType = 'opentype';
+                } else {
+                    mimeType = 'truetype';
+                }
+
+                p5asciify.fontBase64 = `data:font/${mimeType};charset=utf-8;base64,${base64String}`;
+                p5asciify.fontFileType = mimeType;
+            } catch (error) {
+                console.error('Error converting font to Base64:', error);
             }
 
-            p5asciify.fontBase64 = `data:font/${mimeType};charset=utf-8;base64,${base64String}`;
-            p5asciify.fontFileType = mimeType;
-        } catch (error) {
-            console.error('Error converting font to Base64:', error);
-        }
+            // If the sketch is running, update font related components
+            if (p5asciify.p5Instance.frameCount > 0) {
+                try {
+                    p5asciify.asciiFontTextureAtlas.setFontObject(loadedFont);
+
+                    // This is where P5AsciifyError might be thrown if unsupported characters exist
+                    p5asciify.asciiCharacterSet.setCharacterSet(p5asciify.asciiCharacterSet.characters);
+                    p5asciify.edgeCharacterSet.setCharacterSet(p5asciify.edgeCharacterSet.characters);
+
+                    p5asciify.grid.resizeCellPixelDimensions(
+                        p5asciify.asciiFontTextureAtlas.maxGlyphDimensions.width,
+                        p5asciify.asciiFontTextureAtlas.maxGlyphDimensions.height
+                    );
+
+                    p5asciify.brightnessRenderer.resizeFramebuffers();
+                    p5asciify.edgeRenderer.resizeFramebuffers();
+                    p5asciify.customAsciiRenderer.resizeFramebuffers();
+                    p5asciify.accurateRenderer.resizeFramebuffers();
+                    p5asciify.gradientRenderer.resizeFramebuffers();
+
+                    p5asciify.edgeRenderer.resetShaders();
+                    p5asciify.accurateRenderer.resetShaders();
+
+                    p5asciify.textAsciiRenderer.updateFont(p5asciify.fontBase64, p5asciify.fontFileType);
+                } catch (e) {
+                    // Catch any P5AsciifyError and reject the promise
+                    return reject(e);
+                }
+            }
 
-        // If the sketch already runs, update the font texture atlas and grid dimensions, as well as the character sets
-        if (p5asciify.p5Instance.frameCount > 0) {
-            p5asciify.asciiFontTextureAtlas.setFontObject(loadedFont);
-            p5asciify.asciiCharacterSet.setCharacterSet(p5asciify.asciiCharacterSet.characters);
-            p5asciify.edgeCharacterSet.setCharacterSet(p5asciify.edgeCharacterSet.characters);
+            p5asciify.p5Instance._decrementPreload();
+            resolve();
+        };
 
-            p5asciify.grid.resizeCellPixelDimensions(
-                p5asciify.asciiFontTextureAtlas.maxGlyphDimensions.width,
-                p5asciify.asciiFontTextureAtlas.maxGlyphDimensions.height
+        if (typeof font === 'string') {
+            p5asciify.p5Instance.loadFont(
+                font,
+                (loadedFont) => { setFont(loadedFont, font); },
+                () => { reject(new P5AsciifyError(`loadAsciiFont() | Failed to load font from path: '${font}'`)); }
             );
-
-            p5asciify.brightnessRenderer.resizeFramebuffers();
-            p5asciify.edgeRenderer.resizeFramebuffers();
-            p5asciify.customAsciiRenderer.resizeFramebuffers();
-            p5asciify.accurateRenderer.resizeFramebuffers();
-            p5asciify.gradientRenderer.resizeFramebuffers();
-
-            p5asciify.edgeRenderer.resetShaders();
-            p5asciify.accurateRenderer.resetShaders();
-
-            p5asciify.textAsciiRenderer.updateFont(p5asciify.fontBase64, p5asciify.fontFileType);
+        } else {
+            reject(new P5AsciifyError(`loadAsciiFont() | Invalid font parameter. Expected a string/path.`));
         }
-
-        p5asciify.p5Instance._decrementPreload();
-    };
-
-    if (typeof font === 'string') {
-        p5asciify.p5Instance.loadFont(
-            font,
-            (loadedFont) => { setFont(loadedFont, font); },
-            () => { throw new P5AsciifyError(`loadAsciiFont() | Failed to load font from path: '${font}'`); }
-        );
-    } else {
-        throw new P5AsciifyError(`loadAsciiFont() | Invalid font parameter. Expected a string/path.`);
-    }
+    });
 };
+
 p5.prototype.registerPreloadMethod('loadAsciiFont', p5.prototype);
 
 /**