From dfeab303cb3111a13e161b74fc98b0a1de21a447 Mon Sep 17 00:00:00 2001
From: David Greenberg <dgreenberg@cimpress.com>
Date: Fri, 21 Jul 2023 12:18:07 -0400
Subject: [PATCH] Changed viewer to respect alpha, overprint, and spot by
 default.  Also added save as PNG.

---
 platform/wasm/lib/mupdf.c                 | 33 +++++++++++++++++++++--
 platform/wasm/lib/mupdf.js                | 14 ++++++----
 platform/wasm/viewer/mupdf-view-page.js   | 15 +++++++++++
 platform/wasm/viewer/mupdf-view-worker.js | 29 +++++++++++++++++---
 platform/wasm/viewer/mupdf-view.html      |  1 +
 5 files changed, 81 insertions(+), 11 deletions(-)

diff --git a/platform/wasm/lib/mupdf.c b/platform/wasm/lib/mupdf.c
index 9aac5caf27..ee489c4b75 100644
--- a/platform/wasm/lib/mupdf.c
+++ b/platform/wasm/lib/mupdf.c
@@ -282,13 +282,42 @@ fz_pixmap * wasm_get_pixmap_from_image(fz_image *image)
 EXPORT
 fz_pixmap * wasm_new_pixmap_from_page(fz_page *page, fz_matrix *ctm, fz_colorspace *colorspace, int alpha)
 {
-	POINTER(fz_new_pixmap_from_page, page, *ctm, colorspace, alpha)
+	fz_separations *seps = NULL;
+	fz_var(seps);
+	seps = fz_page_separations(ctx, page);
+	if (seps)
+	{
+		int i, n = fz_count_separations(ctx, seps);
+		for (i = 0; i < n; i++)
+			fz_set_separation_behavior(ctx, seps, i, FZ_SEPARATION_SPOT);
+	}
+	POINTER(fz_new_pixmap_from_page_with_separations, page, *ctm, colorspace, seps, alpha)
 }
 
 EXPORT
 fz_pixmap * wasm_new_pixmap_with_bbox(fz_colorspace *colorspace, fz_rect *bbox, int alpha)
 {
-	POINTER(fz_new_pixmap_with_bbox, colorspace, fz_irect_from_rect(*bbox), NULL, alpha)
+	fz_separations *seps = NULL;
+	fz_var(seps);
+	seps = fz_new_separations(ctx, 0);
+	POINTER(fz_new_pixmap_with_bbox, colorspace, fz_irect_from_rect(*bbox), seps, alpha)
+}
+
+EXPORT
+fz_pixmap * wasm_new_pixmap_with_bbox_and_page(fz_colorspace *colorspace, fz_rect *bbox, int alpha, fz_page *page)
+{
+	fz_separations *seps = NULL;
+	fz_var(seps);
+	seps = fz_page_separations(ctx, page);
+	if (seps)
+	{
+		int i, n = fz_count_separations(ctx, seps);
+		for (i = 0; i < n; i++)
+			fz_set_separation_behavior(ctx, seps, i, FZ_SEPARATION_COMPOSITE);
+	} else {
+		seps = fz_new_separations(ctx, 0);
+	}
+	POINTER(fz_new_pixmap_with_bbox, colorspace, fz_irect_from_rect(*bbox), seps, alpha)
 }
 
 EXPORT
diff --git a/platform/wasm/lib/mupdf.js b/platform/wasm/lib/mupdf.js
index dd4baccded..5aee74cd32 100644
--- a/platform/wasm/lib/mupdf.js
+++ b/platform/wasm/lib/mupdf.js
@@ -675,7 +675,7 @@ class DisplayList extends Userdata {
 		return fromRect(libmupdf._wasm_bound_display_list(this))
 	}
 
-	toPixmap(matrix, colorspace, alpha = false) {
+	toPixmap(matrix, colorspace, alpha = true) {
 		checkMatrix(matrix)
 		checkType(colorspace, ColorSpace)
 		return new Pixmap(
@@ -704,11 +704,15 @@ class DisplayList extends Userdata {
 class Pixmap extends Userdata {
 	static _drop = "_wasm_drop_pixmap"
 
-	constructor(arg1, bbox = null, alpha = false) {
+	constructor(arg1, bbox = null, alpha = true, page = null) {
 		let pointer = arg1
 		if (arg1 instanceof ColorSpace) {
 			checkRect(bbox)
-			pointer = libmupdf._wasm_new_pixmap_with_bbox(arg1, RECT(bbox), alpha)
+			if (page) {
+				pointer = libmupdf._wasm_new_pixmap_with_bbox_and_page(arg1, RECT(bbox), alpha, page)
+			} else {
+				pointer = libmupdf._wasm_new_pixmap_with_bbox(arg1, RECT(bbox), alpha)
+			}
 		}
 		super(pointer)
 	}
@@ -1345,7 +1349,7 @@ class Page extends Userdata {
 		libmupdf._wasm_run_page_widgets(this, device, MATRIX(matrix))
 	}
 
-	toPixmap(matrix, colorspace, alpha = false, showExtras = true) {
+	toPixmap(matrix, colorspace, alpha = true, showExtras = true) {
 		checkType(colorspace, ColorSpace)
 		checkMatrix(matrix)
 		let result
@@ -1973,7 +1977,7 @@ class PDFAnnotation extends Userdata {
 		libmupdf._wasm_pdf_run_annot(this, device, MATRIX(matrix))
 	}
 
-	toPixmap(matrix, colorspace, alpha = false) {
+	toPixmap(matrix, colorspace, alpha = true) {
 		checkMatrix(matrix)
 		checkType(colorspace, ColorSpace)
 		return new Pixmap(
diff --git a/platform/wasm/viewer/mupdf-view-page.js b/platform/wasm/viewer/mupdf-view-page.js
index 955d664833..166b77e94f 100644
--- a/platform/wasm/viewer/mupdf-view-page.js
+++ b/platform/wasm/viewer/mupdf-view-page.js
@@ -849,6 +849,21 @@ class MupdfDocumentViewer {
 		this.documentHandler?.goToPage(pageNumber)
 	}
 
+	async saveAsPNG() {
+		let pngs = await this.mupdfWorker.getPngs();
+		for (let i = 0; i < pngs.length; i++) {
+			let png = pngs[i];
+			let blob = new Blob([png], { type: 'image/png' });
+			const link = document.createElement('a');
+			link.href = URL.createObjectURL(blob);
+			link.download = this.documentHandler.title + '_' + (i + 1) + '.png';
+			document.body.append(link);
+			link.click();
+			link.remove();
+			URL.revokeObjectURL(link.href);
+		}
+	}
+
 	toggleFullscreen() {
 		if (!document.fullscreenElement) {
 			this.enterFullscreen()
diff --git a/platform/wasm/viewer/mupdf-view-worker.js b/platform/wasm/viewer/mupdf-view-worker.js
index 503da15562..599c24ba1c 100644
--- a/platform/wasm/viewer/mupdf-view-worker.js
+++ b/platform/wasm/viewer/mupdf-view-worker.js
@@ -196,22 +196,43 @@ workerMethods.drawPageAsPNG = function (pageNumber, dpi) {
 	// TODO - use canvas?
 
 	let page = openDocument.loadPage(pageNumber - 1)
-	let pixmap = page.toPixmap(doc_to_screen, mupdf.DeviceRGB, false)
+	//let pixmap = page.toPixmap(doc_to_screen, mupdf.DeviceRGB, false)
+	let bbox = Rect.transform(page.getBounds(), doc_to_screen)
+	let pixmap = new mupdf.Pixmap(mupdf.ColorSpace.DeviceRGB, bbox, true, page)
 
-	let png = pixmap?.saveAsPNG()
+	let png = pixmap?.asPNG()
 
 	pixmap?.destroy()
 
 	return png
 }
 
+workerMethods.getPngs = function (dpi = 300) {
+	const doc_to_screen = mupdf.Matrix.scale(dpi / 72, dpi / 72);
+	const pages = openDocument.countPages();
+	let pngs = [];
+	for (let i = 0; i < pages; i++) {
+		let page = openDocument.loadPage(i);
+		let bbox = Rect.transform(page.getBounds(), doc_to_screen);
+		let pixmap = new mupdf.Pixmap(mupdf.ColorSpace.DeviceRGB, bbox, true, page);
+		pixmap.clear()
+		let device = new mupdf.DrawDevice(doc_to_screen, pixmap)
+		page.run(device, Matrix.identity)
+		device.close()
+		let png = pixmap?.asPNG();
+		pixmap?.destroy();
+		pngs.push(png);
+	}
+	return pngs;
+};
+
 workerMethods.drawPageAsPixmap = function (pageNumber, dpi) {
 	const doc_to_screen = mupdf.Matrix.scale(dpi / 72, dpi / 72)
 
 	let page = openDocument.loadPage(pageNumber - 1)
 	let bbox = Rect.transform(page.getBounds(), doc_to_screen)
-	let pixmap = new mupdf.Pixmap(mupdf.ColorSpace.DeviceRGB, bbox, true)
-	pixmap.clear(255)
+	let pixmap = new mupdf.Pixmap(mupdf.ColorSpace.DeviceRGB, bbox, true, page)
+	pixmap.clear()
 
 	let device = new mupdf.DrawDevice(doc_to_screen, pixmap)
 	page.run(device, Matrix.identity)
diff --git a/platform/wasm/viewer/mupdf-view.html b/platform/wasm/viewer/mupdf-view.html
index bda23b9970..5df0e5a7bb 100644
--- a/platform/wasm/viewer/mupdf-view.html
+++ b/platform/wasm/viewer/mupdf-view.html
@@ -210,6 +210,7 @@
 		<div class="menu-button">File</div>
 		<div class="menu-popup">
 			<div onclick="document.getElementById('open-file-input').click()">Open File...</div>
+			<div onclick="documentViewer?.saveAsPNG()">Save as PNG</div>
 		</div>
 	</div>
 	<div class="menu">