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Trim transparent space on SVG and PNG exports #4

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Trim transparent space on SVG and PNG exports #4

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56 changes: 39 additions & 17 deletions assets/app.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1005,6 +1005,23 @@ self.onmessage = function(e) {
showHowtoIfNeeded();

// --- Exporters ---
const getPathBoundingBox = (paths, sx, sy) => {
if (!paths || paths.length === 0) return { minX: 0, minY: 0, maxX: 0, maxY: 0 };
let minX = Infinity, minY = Infinity, maxX = -Infinity, maxY = -Infinity;
for (const path of paths) {
for (const pt of path) {
const x = pt.x * sx;
const y = pt.y * sy;
if (x < minX) minX = x;
if (y < minY) minY = y;
if (x > maxX) maxX = x;
if (y > maxY) maxY = y;
}
}
if (minX === Infinity) return { minX: 0, minY: 0, maxX: 0, maxY: 0 };
return { minX, minY, maxX, maxY };
};

const formatSvgNumber = (value, precision = 2) => Number.isFinite(value) ? Number(value.toFixed(precision)).toString() : '0';

const getSvgPathString = (pts, closed, precision = 2) => {
Expand Down Expand Up @@ -1069,12 +1086,14 @@ self.onmessage = function(e) {

els.btnExportSvg.addEventListener('click', () => {
if (state.paths.length === 0) return;
const outputW = state.originalWidth || state.imageObj.width;
const outputH = state.originalHeight || state.imageObj.height;
const sx = state.traceScaleX || 1;
const sy = state.traceScaleY || 1;

const scalePts = (pts, stride = 1) => thinSvgPoints(pts, stride).map(pt => ({ x: pt.x * sx, y: pt.y * sy }));
const bbox = getPathBoundingBox(state.paths, sx, sy);
const trimmedW = Math.max(1, bbox.maxX - bbox.minX);
const trimmedH = Math.max(1, bbox.maxY - bbox.minY);

const scalePts = (pts, stride = 1) => thinSvgPoints(pts, stride).map(pt => ({ x: pt.x * sx - bbox.minX, y: pt.y * sy - bbox.minY }));
const makeSvgPath = (precision = 2, stride = 1) => state.paths.map(p => getSvgPathString(scalePts(p, stride), true, precision)).join(' ');
const fullSvgPath = makeSvgPath();

Expand All @@ -1083,15 +1102,15 @@ self.onmessage = function(e) {
if (textureDataUrl) {
if (state.fillMode === 'pattern') {
const pWidth = state.fillImageObj.width * state.fillScale * sx, pHeight = state.fillImageObj.height * state.fillScale * sy;
svgContent = `<defs><pattern id="fill-pattern" patternUnits="userSpaceOnUse" width="${formatSvgNumber(pWidth)}" height="${formatSvgNumber(pHeight)}" patternTransform="translate(${formatSvgNumber(state.fillOffsetX * sx)}, ${formatSvgNumber(state.fillOffsetY * sy)})"><image href="${textureDataUrl}" x="0" y="0" width="${formatSvgNumber(pWidth)}" height="${formatSvgNumber(pHeight)}" /></pattern></defs><path d="${svgPath}" fill="url(#fill-pattern)" fill-rule="evenodd" stroke="none" />`;
svgContent = `<defs><pattern id="fill-pattern" patternUnits="userSpaceOnUse" width="${formatSvgNumber(pWidth)}" height="${formatSvgNumber(pHeight)}" patternTransform="translate(${formatSvgNumber(state.fillOffsetX * sx - bbox.minX)}, ${formatSvgNumber(state.fillOffsetY * sy - bbox.minY)})"><image href="${textureDataUrl}" x="0" y="0" width="${formatSvgNumber(pWidth)}" height="${formatSvgNumber(pHeight)}" /></pattern></defs><path d="${svgPath}" fill="url(#fill-pattern)" fill-rule="evenodd" stroke="none" />`;
} else {
const imgWidth = state.fillImageObj.width * state.fillScale * sx, imgHeight = state.fillImageObj.height * state.fillScale * sy;
svgContent = `<defs><clipPath id="shape-clip"><path d="${svgPath}" clip-rule="evenodd" /></clipPath></defs><image href="${textureDataUrl}" x="${formatSvgNumber(state.fillOffsetX * sx)}" y="${formatSvgNumber(state.fillOffsetY * sy)}" width="${formatSvgNumber(imgWidth)}" height="${formatSvgNumber(imgHeight)}" clip-path="url(#shape-clip)" />`;
svgContent = `<defs><clipPath id="shape-clip"><path d="${svgPath}" clip-rule="evenodd" /></clipPath></defs><image href="${textureDataUrl}" x="${formatSvgNumber(state.fillOffsetX * sx - bbox.minX)}" y="${formatSvgNumber(state.fillOffsetY * sy - bbox.minY)}" width="${formatSvgNumber(imgWidth)}" height="${formatSvgNumber(imgHeight)}" clip-path="url(#shape-clip)" />`;
}
} else {
svgContent = ` <path d="${svgPath}" fill="black" fill-rule="evenodd" stroke="none" />`;
}
return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${formatSvgNumber(outputW)} ${formatSvgNumber(outputH)}" width="${formatSvgNumber(outputW)}" height="${formatSvgNumber(outputH)}"><rect width="100%" height="100%" fill="white" />${svgContent}</svg>`;
return `<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 ${formatSvgNumber(trimmedW)} ${formatSvgNumber(trimmedH)}" width="${formatSvgNumber(trimmedW)}" height="${formatSvgNumber(trimmedH)}">${svgContent}</svg>`;
};

let blob = svgBlobFromString(buildSvg());
Expand Down Expand Up @@ -1137,16 +1156,19 @@ self.onmessage = function(e) {

els.btnExportPng.addEventListener('click', () => {
if (state.paths.length === 0) return;
const outputW = state.originalWidth || state.imageObj.width;
const outputH = state.originalHeight || state.imageObj.height;
const sx = state.traceScaleX || 1;
const sy = state.traceScaleY || 1;
const pngScale = getPngExportScale(outputW, outputH);
const exportW = Math.max(1, Math.round(outputW * pngScale));
const exportH = Math.max(1, Math.round(outputH * pngScale));
const ex = exportW / outputW;
const ey = exportH / outputH;
const scalePts = (pts) => pts.map(pt => ({ x: pt.x * sx * ex, y: pt.y * sy * ey }));

const bbox = getPathBoundingBox(state.paths, sx, sy);
const trimmedW = Math.max(1, bbox.maxX - bbox.minX);
const trimmedH = Math.max(1, bbox.maxY - bbox.minY);

const pngScale = getPngExportScale(trimmedW, trimmedH);
const exportW = Math.max(1, Math.round(trimmedW * pngScale));
const exportH = Math.max(1, Math.round(trimmedH * pngScale));
const ex = exportW / trimmedW;
const ey = exportH / trimmedH;
const scalePts = (pts) => pts.map(pt => ({ x: (pt.x * sx - bbox.minX) * ex, y: (pt.y * sy - bbox.minY) * ey }));

const expCanvas = document.createElement('canvas');
expCanvas.width = exportW;
Expand All @@ -1166,16 +1188,16 @@ self.onmessage = function(e) {
enableHighQualitySmoothing(pCtx);
pCtx.drawImage(state.fillImageObj, 0, 0, pCanvas.width, pCanvas.height);
const pattern = eCtx.createPattern(pCanvas, 'repeat');
pattern.setTransform(new DOMMatrix().translate(state.fillOffsetX * sx * ex, state.fillOffsetY * sy * ey));
pattern.setTransform(new DOMMatrix().translate((state.fillOffsetX * sx - bbox.minX) * ex, (state.fillOffsetY * sy - bbox.minY) * ey));
eCtx.fillStyle = pattern;
eCtx.fill('evenodd');
} else {
eCtx.save();
eCtx.clip('evenodd');
eCtx.drawImage(
state.fillImageObj,
state.fillOffsetX * sx * ex,
state.fillOffsetY * sy * ey,
(state.fillOffsetX * sx - bbox.minX) * ex,
(state.fillOffsetY * sy - bbox.minY) * ey,
Math.max(1, Math.round(state.fillImageObj.width * state.fillScale * sx * ex)),
Math.max(1, Math.round(state.fillImageObj.height * state.fillScale * sy * ey))
);
Expand Down