wip compile blockstates

src/minerama.js

@@ -0,0 +1,114 @@
+export class Renderer {
+    constructor() {
+        this.canvas = document.createElement('canvas');
+        this.canvas.style.display = 'none';
+        document.body.appendChild(this.canvas);
+        this.gl = this.canvas.getContext('webgl2', {antialias: false, alpha: true})
+    }
+}
+
+function renderVariantCondition(key) {
+    if (key) {
+        return key.split(',').map(
+            it => it.split("=")
+        ).map(
+            ([n, v]) => `state[${JSON.stringify(n)}] === ${JSON.stringify(v)}`
+        ).join(" && ")
+    } else {
+        return 'true';
+    }
+}
+
+function renderApply(data) {
+    if (Array.isArray(data)) {
+        const parts = [];
+
+        let total = 0.0;
+        for (const {weight = 1.0} of data) total += weight;
+
+        let accum = 0.0;
+        for (const elem of data) {
+            const {weight = 1.0} = elem;
+            accum += weight;
+
+            if (accum === total) {
+                parts.push(JSON.stringify(elem));
+            } else {
+                parts.push(`(hash % ${total}) < ${accum} ? ${JSON.stringify(elem)} : `)
+            }
+        }
+        return parts.join('');
+    } else {
+        return JSON.stringify(data)
+    }
+}
+
+/**
+ * @param {Object} data
+ * @returns {String}
+ */
+function renderBlockstateResolver(data) {
+    const {variants, multipart} = data;
+
+    if (variants) {
+        if (Object.keys(variants).length === 1 && variants[""]) {
+            return `return ${(renderApply(variants[""]))};`;
+        } else {
+            let cases = [];
+            for (const [key, defn] of Object.entries(variants)) {
+                cases.push(`if (${(renderVariantCondition(key))}) return ${(renderApply(defn))};`)
+            }
+            cases.push(`return {"model": ":missing"};`)
+            return cases.join('else ')
+        }
+    } else if (multipart) {
+        return 'console.warn("NOT IMPLEMENTED")'
+    } else {
+        console.warn('invalid blockstate', data)
+    }
+}
+
+/**
+ * @param {String} src
+ * @returns {Promise<void>}
+ */
+async function parse(src) {
+    const lines = src.replace(/#.*?(?:\n|$)/, '\n').trim().split(/(?:\n[ \t]*)+/);
+
+    for (const line of lines) {
+        const args = line.split(/[ \t]+/);
+        const cmd = args[0].toLowerCase();
+
+        if (cmd === 'p') {
+            const block = args[1];
+
+            try {
+                const res = await fetch(`assets/minecraft/blockstates/${block}.json`);
+                let data = await res.json();
+                let resolver_src = renderBlockstateResolver(data);
+                // console.log(beautify.js(`${block} = (state, hash) => {${resolver_src}}`))
+
+                let resolver = new Function("state", "hash", resolver_src);
+                console.log(resolver)
+
+            } catch (ex) {
+                console.warn(`Fetch for ${block} failed:`, ex);
+            }
+        }
+    }
+}
+
+export class MCDioramaElement extends HTMLElement {
+    connectedCallback() {
+        const canvas = document.createElement('canvas');
+        this.appendChild(canvas);
+        const ctx = canvas.getContext('2d');
+
+        setTimeout(() => {
+            const script = this.querySelector('script[type="text/mc-world"]');
+            parse(script.textContent);
+        }, 0)
+    }
+}
+
+customElements.define('mc-diorama', MCDioramaElement);