From 96b0a2e0316111e0967ebe557fbb2e513f44cf45 Mon Sep 17 00:00:00 2001
From: DreamPiggy <lizhuoli1126@126.com>
Date: Thu, 30 Jan 2020 15:11:42 +0800
Subject: [PATCH] Added the default ImageIO coder with PDF support, use the
 screen size if user does not provide any explict pixel size

---
 SDWebImage/Core/SDImageIOAnimatedCoder.m | 50 ++++++++++++++++++------
 1 file changed, 39 insertions(+), 11 deletions(-)

diff --git a/SDWebImage/Core/SDImageIOAnimatedCoder.m b/SDWebImage/Core/SDImageIOAnimatedCoder.m
index b72dc4e0..1db7a495 100644
--- a/SDWebImage/Core/SDImageIOAnimatedCoder.m
+++ b/SDWebImage/Core/SDImageIOAnimatedCoder.m
@@ -14,6 +14,9 @@
 #import "SDAnimatedImageRep.h"
 #import "UIImage+ForceDecode.h"
 
+// Specify DPI for vector format in CGImageSource, like PDF
+static NSString * kSDCGImageSourceRasterizationDPI = @"kCGImageSourceRasterizationDPI";
+
 @interface SDImageIOCoderFrame : NSObject
 
 @property (nonatomic, assign) NSUInteger index; // Frame index (zero based)
@@ -158,9 +161,33 @@
         exifOrientation = kCGImagePropertyOrientationUp;
     }
     
+    CFStringRef uttype = CGImageSourceGetType(source);
+    // Check vector format
+    BOOL isVector = NO;
+    if ([NSData sd_imageFormatFromUTType:uttype] == SDImageFormatPDF) {
+        isVector = YES;
+    }
+    
     CGImageRef imageRef;
-    if (thumbnailSize.width == 0 || thumbnailSize.height == 0 || (pixelWidth <= thumbnailSize.width && pixelHeight <= thumbnailSize.height)) {
-        imageRef = CGImageSourceCreateImageAtIndex(source, index, NULL);
+    if (thumbnailSize.width == 0 || thumbnailSize.height == 0 || pixelWidth == 0 || pixelHeight == 0 || (pixelWidth <= thumbnailSize.width && pixelHeight <= thumbnailSize.height)) {
+        NSDictionary *options;
+        if (isVector) {
+            if (thumbnailSize.width == 0 || thumbnailSize.height == 0) {
+                // Provide the default pixel count for vector images, simply just use the screen size
+#if SD_WATCH
+                thumbnailSize = WKInterfaceDevice.currentDevice.screenBounds.size;
+#elif SD_UIKIT
+                thumbnailSize = UIScreen.mainScreen.bounds.size;
+#elif SD_MAC
+                thumbnailSize = NSScreen.mainScreen.frame.size;
+#endif
+            }
+            CGFloat maxPixelSize = MAX(thumbnailSize.width, thumbnailSize.height);
+            NSUInteger DPIPerPixel = 2;
+            NSUInteger rasterizationDPI = maxPixelSize * DPIPerPixel;
+            options = @{kSDCGImageSourceRasterizationDPI : @(rasterizationDPI)};
+        }
+        imageRef = CGImageSourceCreateImageAtIndex(source, index, (__bridge CFDictionaryRef)options);
     } else {
         NSMutableDictionary *thumbnailOptions = [NSMutableDictionary dictionary];
         thumbnailOptions[(__bridge NSString *)kCGImageSourceCreateThumbnailWithTransform] = @(preserveAspectRatio);
@@ -179,21 +206,22 @@
         thumbnailOptions[(__bridge NSString *)kCGImageSourceThumbnailMaxPixelSize] = @(maxPixelSize);
         thumbnailOptions[(__bridge NSString *)kCGImageSourceCreateThumbnailFromImageIfAbsent] = @(YES);
         imageRef = CGImageSourceCreateThumbnailAtIndex(source, index, (__bridge CFDictionaryRef)thumbnailOptions);
+    }
+    if (!imageRef) {
+        return nil;
+    }
+    
+    if (thumbnailSize.width > 0 && thumbnailSize.height > 0) {
         if (preserveAspectRatio) {
             // kCGImageSourceCreateThumbnailWithTransform will apply EXIF transform as well, we should not apply twice
             exifOrientation = kCGImagePropertyOrientationUp;
         } else {
             // `CGImageSourceCreateThumbnailAtIndex` take only pixel dimension, if not `preserveAspectRatio`, we should manual scale to the target size
-            if (imageRef) {
-                CGImageRef scaledImageRef = [SDImageCoderHelper CGImageCreateScaled:imageRef size:thumbnailSize];
-                CGImageRelease(imageRef);
-                imageRef = scaledImageRef;
-            }
+            CGImageRef scaledImageRef = [SDImageCoderHelper CGImageCreateScaled:imageRef size:thumbnailSize];
+            CGImageRelease(imageRef);
+            imageRef = scaledImageRef;
         }
     }
-    if (!imageRef) {
-        return nil;
-    }
     
 #if SD_UIKIT || SD_WATCH
     UIImageOrientation imageOrientation = [SDImageCoderHelper imageOrientationFromEXIFOrientation:exifOrientation];
@@ -363,7 +391,7 @@
         if (scaleFactor != nil) {
             scale = MAX([scaleFactor doubleValue], 1);
         }
-        image = [SDImageIOAnimatedCoder createFrameAtIndex:0 source:_imageSource scale:scale preserveAspectRatio:_preserveAspectRatio thumbnailSize:_thumbnailSize];
+        image = [self.class createFrameAtIndex:0 source:_imageSource scale:scale preserveAspectRatio:_preserveAspectRatio thumbnailSize:_thumbnailSize];
         if (image) {
             image.sd_imageFormat = self.class.imageFormat;
         }