From 6bacb386924e13c0713c68749683c3d1b1ba02d5 Mon Sep 17 00:00:00 2001
From: mduan <duan.mack@gmail.com>
Date: Tue, 15 Jan 2013 16:40:39 -0800
Subject: [PATCH] Make canvas transform matrix account for devicePixelRatio

---
 src/canvas.js | 4 +++-
 web/viewer.js | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/canvas.js b/src/canvas.js
index 088e6c236..57861a940 100644
--- a/src/canvas.js
+++ b/src/canvas.js
@@ -46,6 +46,8 @@ function addContextCurrentTransform(ctx) {
   // If the context doesn't expose a `mozCurrentTransform`, add a JS based on.
   if (!ctx.mozCurrentTransform) {
     // Store the original context
+    ctx._scaleX = ctx._scaleX || 1.0;
+    ctx._scaleY = ctx._scaleY || 1.0;
     ctx._originalSave = ctx.save;
     ctx._originalRestore = ctx.restore;
     ctx._originalRotate = ctx.rotate;
@@ -53,7 +55,7 @@ function addContextCurrentTransform(ctx) {
     ctx._originalTranslate = ctx.translate;
     ctx._originalTransform = ctx.transform;
 
-    ctx._transformMatrix = [1, 0, 0, 1, 0, 0];
+    ctx._transformMatrix = [ctx._scaleX, 0, 0, ctx._scaleY, 0, 0];
     ctx._transformStack = [];
 
     Object.defineProperty(ctx, 'mozCurrentTransform', {
diff --git a/web/viewer.js b/web/viewer.js
index d2e622761..704fd75e1 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -2048,6 +2048,9 @@ var PageView = function pageView(container, pdfPage, id, scale,
     }
 
     var ctx = canvas.getContext('2d');
+    // TODO(mack): use data attributes to store these
+    ctx._scaleX = outputScale.sx;
+    ctx._scaleY = outputScale.sy;
     ctx.save();
     ctx.fillStyle = 'rgb(255, 255, 255)';
     ctx.fillRect(0, 0, canvas.width, canvas.height);