V1_commit_RGC

SuiviREForamteur/node_modules/fast-png/lib/convertIndexedToRgb.js

@@ -0,0 +1,73 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.convertIndexedToRgb = convertIndexedToRgb;
+/**
+ * Converts indexed data into RGB/RGBA format
+ * @param decodedImage - Image to decode data from.
+ * @returns Uint8Array with RGB data.
+ */
+function convertIndexedToRgb(decodedImage) {
+    const palette = decodedImage.palette;
+    const depth = decodedImage.depth;
+    if (!palette) {
+        throw new Error('Color palette is undefined.');
+    }
+    checkDataSize(decodedImage);
+    const indexSize = decodedImage.width * decodedImage.height;
+    const resSize = indexSize * palette[0].length;
+    const res = new Uint8Array(resSize);
+    let indexPos = 0;
+    let offset = 0;
+    const indexes = new Uint8Array(indexSize);
+    let bit = 0xff;
+    switch (depth) {
+        case 1:
+            bit = 0x80;
+            break;
+        case 2:
+            bit = 0xc0;
+            break;
+        case 4:
+            bit = 0xf0;
+            break;
+        case 8:
+            bit = 0xff;
+            break;
+        default:
+            throw new Error('Incorrect depth value');
+    }
+    for (const byte of decodedImage.data) {
+        let bit2 = bit;
+        let shift = 8;
+        while (bit2) {
+            shift -= depth;
+            indexes[indexPos++] = (byte & bit2) >> shift;
+            bit2 = bit2 >> depth;
+            if (indexPos % decodedImage.width === 0) {
+                break;
+            }
+        }
+    }
+    if (decodedImage.palette) {
+        for (const index of indexes) {
+            const color = decodedImage.palette.at(index);
+            if (!color) {
+                throw new Error('Incorrect index of palette color');
+            }
+            res.set(color, offset);
+            offset += color.length;
+        }
+    }
+    return res;
+}
+function checkDataSize(image) {
+    const expectedSize = image.depth < 8
+        ? Math.ceil((image.width * image.depth) / 8) *
+            image.height *
+            image.channels
+        : image.width * image.height * image.channels;
+    if (image.data.length !== expectedSize) {
+        throw new RangeError(`wrong data size. Found ${image.data.length}, expected ${expectedSize}`);
+    }
+}
+//# sourceMappingURL=convertIndexedToRgb.js.map