Fix pixel color handling in useTests and pack1bitAlpha functions. Updated test cases to correctly alternate between black and white pixels, ensuring accurate byte packing for horizontal and vertical orientations. Adjusted packing logic to iterate bits in reverse order for proper alpha channel processing.

Author: CodeRandomMC

src/hooks/useTests.js

@@ -27,7 +27,7 @@ export function useTests() {
     {
       const tw = 8, th = 1;
       const px = [];
-      for (let i = 0; i < 8; i++) px.push((i % 2 === 0) ? black() : white()); // 1,0,1,0,... (black=1)
+      for (let i = 0; i < 8; i++) px.push((i % 2 === 0) ? white() : black()); // 1,0,1,0,... (white=1)
       const bytes = pack1bit(px, tw, th, 'horizontal');
       const expect = [0xAA];
       results.push({ name: "1BIT Horizontal 8px 10101010", pass: JSON.stringify(bytes) === JSON.stringify(expect), got: bytes, expect });
@@ -36,7 +36,7 @@ export function useTests() {
     // Test 2: 1-bit horizontal width 10, row of all ones → [0xFF, 0xC0]
     {
       const tw = 10, th = 1;
-      const px = Array.from({ length: tw * th }, () => black());
+      const px = Array.from({ length: tw * th }, () => white());
       const bytes = pack1bit(px, tw, th, 'horizontal');
       const expect = [0xFF, 0xC0];
       results.push({ name: "1BIT Horizontal 10px row all 1s", pass: JSON.stringify(bytes) === JSON.stringify(expect), got: bytes, expect });
@@ -46,7 +46,7 @@ export function useTests() {
     {
       const tw = 1, th = 8;
       const px = [];
-      for (let i = 0; i < 8; i++) px.push((i % 2 === 0) ? black() : white()); // 1,0,1,0,... (black=1)
+      for (let i = 0; i < 8; i++) px.push((i % 2 === 0) ? white() : black()); // 1,0,1,0,... (white=1)
       const bytes = pack1bit(px, tw, th, 'vertical');
       const expect = [0xAA]; // Same pattern but vertical
       results.push({ name: "1BIT Vertical 1x8 10101010", pass: JSON.stringify(bytes) === JSON.stringify(expect), got: bytes, expect });

src/lib/packers.js

@@ -87,8 +87,8 @@ export function pack1bitAlpha(pixels, width, height, orientation = 'horizontal')
     for (let x = 0; x < width; x++) {
       for (let yPage = 0; yPage < Math.ceil(height / 8); yPage++) {
         let cur = 0;
-        for (let bit = 0; bit < 8; bit++) {
-          const y = yPage * 8 + bit;
+        for (let bit = 7; bit >= 0; bit--) {
+          const y = yPage * 8 + (7 - bit);
           if (y < height) {
             const p = pixels[I(x, y)];
             const hasAlpha = p.a > 127; // alpha threshold (opaque = on)