Add texture padder tool

This commit is contained in:
2026-04-13 20:34:54 -05:00
parent 5f2d871bad
commit 041ec3d710
6 changed files with 422 additions and 13 deletions
@@ -0,0 +1,275 @@
"use strict";
// ─── Helpers ─────────────────────────────────────────────────────────────────
// Returns the smallest power of two >= n.
function nextPow2(n) {
if (n <= 0) return 1;
let p = 1;
while (p < n) p <<= 1;
return p;
}
// ─── State ───────────────────────────────────────────────────────────────────
const state = {
pixels: null, // Uint8ClampedArray RGBA at original resolution
width: 0,
height: 0,
scale: 1,
bg: "grid",
padWidthPow2: true,
padHeightPow2: true,
minWidth4: true,
minHeight4: true,
format: DTF.FORMAT_RGBA,
filename: "texture",
};
// ─── DOM refs ────────────────────────────────────────────────────────────────
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
const fileInput = document.getElementById("file-input");
const loadLabel = document.getElementById("load-label");
const scaleInput = document.getElementById("scale-input");
const bgSwatches = document.getElementById("bg-swatches");
const previewArea = document.getElementById("preview-area");
const previewEmpty = document.getElementById("preview-empty");
const previewScroll = document.getElementById("preview-scroll");
const infoSection = document.getElementById("info-section");
const fileNameEl = document.getElementById("file-name");
const infoFilename = document.getElementById("info-filename");
const infoInputSize = document.getElementById("info-input-size");
const infoOutputSize = document.getElementById("info-output-size");
const formatSelect = document.getElementById("format-select");
const btnDtf = document.getElementById("btn-dtf");
const btnPng = document.getElementById("btn-png");
const infoDtfSize = document.getElementById("info-dtf-size");
const chkPadWidthPow2 = document.getElementById("chk-pad-width-pow2");
const chkPadHeightPow2 = document.getElementById("chk-pad-height-pow2");
const chkMinWidth4 = document.getElementById("chk-min-width-4");
const chkMinHeight4 = document.getElementById("chk-min-height-4");
// ─── Padding logic ───────────────────────────────────────────────────────────
function computeOutputSize() {
let outW = state.width;
let outH = state.height;
// Apply minimum-size constraints first so pow2 rounding accounts for them.
if (state.minWidth4 && outW < 4) outW = 4;
if (state.minHeight4 && outH < 4) outH = 4;
if (state.padWidthPow2) outW = nextPow2(outW);
if (state.padHeightPow2) outH = nextPow2(outH);
return { outW, outH };
}
function buildPaddedPixels() {
const { outW, outH } = computeOutputSize();
const src = state.pixels;
// Zero-filled Uint8ClampedArray = fully transparent black padding.
const out = new Uint8ClampedArray(outW * outH * 4);
for (let y = 0; y < state.height; y++) {
for (let x = 0; x < state.width; x++) {
const si = (y * state.width + x) * 4;
const di = (y * outW + x) * 4;
out[di] = src[si];
out[di + 1] = src[si + 1];
out[di + 2] = src[si + 2];
out[di + 3] = src[si + 3];
}
}
return { pixels: out, width: outW, height: outH };
}
// ─── Rendering ───────────────────────────────────────────────────────────────
const CHECKER_CELL = 8;
function drawCheckerboard(w, h) {
for (let y = 0; y < h; y += CHECKER_CELL) {
for (let x = 0; x < w; x += CHECKER_CELL) {
ctx.fillStyle = ((x / CHECKER_CELL + y / CHECKER_CELL) % 2 === 0) ? "#c8c8c8" : "#ffffff";
ctx.fillRect(x, y, Math.min(CHECKER_CELL, w - x), Math.min(CHECKER_CELL, h - y));
}
}
}
function render() {
if (!state.pixels) return;
const { pixels, width, height } = buildPaddedPixels();
const cw = width * state.scale;
const ch = height * state.scale;
canvas.width = cw;
canvas.height = ch;
if (state.bg === "grid") {
drawCheckerboard(cw, ch);
} else {
ctx.fillStyle = state.bg;
ctx.fillRect(0, 0, cw, ch);
}
const src = Object.assign(document.createElement("canvas"), { width, height });
src.getContext("2d").putImageData(new ImageData(pixels, width, height), 0, 0);
ctx.imageSmoothingEnabled = false;
ctx.drawImage(src, 0, 0, cw, ch);
}
// ─── Info update ─────────────────────────────────────────────────────────────
function updateInfo() {
if (!state.pixels) return;
const { outW, outH } = computeOutputSize();
const bytes = DTF.HEADER_SIZE + outW * outH * DTF.BPP[state.format];
infoInputSize.textContent = `${state.width} × ${state.height}`;
infoOutputSize.textContent = `${outW} × ${outH}`;
infoDtfSize.textContent = `${(bytes / 1024).toFixed(1)} KB`;
}
// ─── Loading ─────────────────────────────────────────────────────────────────
function loadStandardImage(file) {
const url = URL.createObjectURL(file);
const img = new Image();
img.onload = () => {
const offscreen = Object.assign(document.createElement("canvas"), {
width: img.naturalWidth,
height: img.naturalHeight,
});
offscreen.getContext("2d").drawImage(img, 0, 0);
const imageData = offscreen.getContext("2d").getImageData(0, 0, img.naturalWidth, img.naturalHeight);
applyImageData(img.naturalWidth, img.naturalHeight, imageData.data, file.name);
URL.revokeObjectURL(url);
};
img.onerror = () => {
alert("Failed to load image. The file may be corrupt or unsupported.");
URL.revokeObjectURL(url);
};
img.src = url;
}
function loadDTF(file) {
const reader = new FileReader();
reader.onload = e => {
try {
const { width, height, data } = DTF.decode(e.target.result);
applyImageData(width, height, data, file.name);
} catch (err) {
alert(`Failed to load DTF: ${err.message}`);
}
};
reader.readAsArrayBuffer(file);
}
function applyImageData(width, height, data, filename) {
state.pixels = new Uint8ClampedArray(data);
state.width = width;
state.height = height;
state.filename = filename.replace(/\.[^/.]+$/, "");
fileNameEl.textContent = filename;
infoFilename.textContent = filename;
infoSection.hidden = false;
updateInfo();
previewEmpty.hidden = true;
previewScroll.hidden = false;
btnDtf.disabled = false;
btnPng.disabled = false;
render();
}
function handleFile(file) {
if (!file) return;
if (file.name.toLowerCase().endsWith(".dtf")) {
loadDTF(file);
} else {
loadStandardImage(file);
}
}
// ─── Export ───────────────────────────────────────────────────────────────────
function exportDTF() {
if (!state.pixels) return;
const { pixels, width, height } = buildPaddedPixels();
const buf = DTF.encode(width, height, pixels, state.format);
const blob = new Blob([buf], { type: "application/octet-stream" });
const url = URL.createObjectURL(blob);
const a = Object.assign(document.createElement("a"), {
href: url,
download: `${state.filename}.dtf`,
});
a.click();
URL.revokeObjectURL(url);
}
function exportPNG() {
if (!state.pixels) return;
const { pixels, width, height } = buildPaddedPixels();
DuskPNG.download(`${state.filename}.png`, width, height, pixels);
}
// ─── Event listeners ─────────────────────────────────────────────────────────
fileInput.addEventListener("change", e => handleFile(e.target.files[0]));
scaleInput.addEventListener("input", () => {
const v = Math.max(1, Math.min(10, parseInt(scaleInput.value, 10) || 1));
scaleInput.value = v;
state.scale = v;
render();
});
bgSwatches.addEventListener("click", e => {
const btn = e.target.closest(".bg-swatch");
if (!btn) return;
bgSwatches.querySelectorAll(".bg-swatch").forEach(b => b.classList.remove("active"));
btn.classList.add("active");
state.bg = btn.dataset.bg;
render();
});
formatSelect.addEventListener("change", () => {
state.format = parseInt(formatSelect.value, 10);
updateInfo();
});
btnDtf.addEventListener("click", exportDTF);
btnPng.addEventListener("click", exportPNG);
chkPadWidthPow2.addEventListener("change", () => { state.padWidthPow2 = chkPadWidthPow2.checked; updateInfo(); render(); });
chkPadHeightPow2.addEventListener("change", () => { state.padHeightPow2 = chkPadHeightPow2.checked; updateInfo(); render(); });
chkMinWidth4.addEventListener("change", () => { state.minWidth4 = chkMinWidth4.checked; updateInfo(); render(); });
chkMinHeight4.addEventListener("change", () => { state.minHeight4 = chkMinHeight4.checked; updateInfo(); render(); });
// Drag-and-drop
function setupDrop(target) {
target.addEventListener("dragover", e => {
e.preventDefault();
loadLabel.classList.add("drag-over");
previewArea.classList.add("drag-over");
});
target.addEventListener("dragleave", () => {
loadLabel.classList.remove("drag-over");
previewArea.classList.remove("drag-over");
});
target.addEventListener("drop", e => {
e.preventDefault();
loadLabel.classList.remove("drag-over");
previewArea.classList.remove("drag-over");
handleFile(e.dataTransfer.files[0]);
});
}
setupDrop(loadLabel);
setupDrop(previewArea);