GPUImagePicture: only access image bytes directly if the bitmap byte …

…order and format is compatible with GL This correct non-redrawing for JPGs from my previous commit, as they are big endian.
weibobo · Oct 20, 2013 · 62c8311 · 62c8311
1 parent 08d1521
commit 62c8311
Showing 1 changed file with 32 additions and 2 deletions.
diff --git a/framework/Source/iOS/GPUImagePicture.m b/framework/Source/iOS/GPUImagePicture.m
@@ -98,12 +98,42 @@ - (id)initWithCGImage:(CGImageRef)newImageSource smoothlyScaleOutput:(BOOL)smoot
 
     GLubyte *imageData = NULL;
     CFDataRef dataFromImageDataProvider;
+    GLenum format = GL_BGRA;
+
+    if (!shouldRedrawUsingCoreGraphics) {
+        /* Check that the bitmap pixel format is compatible with GL */
+        CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(newImageSource);
+        if ((bitmapInfo & kCGBitmapFloatComponents) != 0) {
+            /* We don't support float components for use directly in GL */
+            shouldRedrawUsingCoreGraphics = YES;
+        } else {
+            CGBitmapInfo byteOrderInfo = bitmapInfo & kCGBitmapByteOrderMask;
+            if (byteOrderInfo == kCGBitmapByteOrder32Little) {
+                /* Little endian, for alpha-first we can use this bitmap directly in GL */
+                CGImageAlphaInfo alphaInfo = bitmapInfo & kCGBitmapAlphaInfoMask;
+                if (alphaInfo != kCGImageAlphaPremultipliedFirst && alphaInfo != kCGImageAlphaFirst &&
+                    alphaInfo != kCGImageAlphaNoneSkipFirst) {
+                    shouldRedrawUsingCoreGraphics = YES;
+                }
+            } else if (byteOrderInfo == kCGBitmapByteOrderDefault || byteOrderInfo == kCGBitmapByteOrder32Big) {
+                /* Big endian, for alpha-last we can use this bitmap directly in GL */
+                CGImageAlphaInfo alphaInfo = bitmapInfo & kCGBitmapAlphaInfoMask;
+                if (alphaInfo != kCGImageAlphaPremultipliedLast && alphaInfo != kCGImageAlphaLast &&
+                    alphaInfo != kCGImageAlphaNoneSkipLast) {
+                    shouldRedrawUsingCoreGraphics = YES;
+                } else {
+                    /* Can access directly using GL_RGBA pixel format */
+                    format = GL_RGBA;
+                }
+            }
+        }
+    }
 
     //    CFAbsoluteTime elapsedTime, startTime = CFAbsoluteTimeGetCurrent();
 
     if (shouldRedrawUsingCoreGraphics)
     {
-        // For resized image, redraw
+        // For resized or incompatible image: redraw
         imageData = (GLubyte *) calloc(1, (int)pixelSizeToUseForTexture.width * (int)pixelSizeToUseForTexture.height * 4);
 
         CGColorSpaceRef genericRGBColorspace = CGColorSpaceCreateDeviceRGB();
@@ -148,7 +178,7 @@ - (id)initWithCGImage:(CGImageRef)newImageSource smoothlyScaleOutput:(BOOL)smoot
             glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
         }
         // no need to use self.outputTextureOptions here since pictures need this texture formats and type
-        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (int)pixelSizeToUseForTexture.width, (int)pixelSizeToUseForTexture.height, 0, GL_BGRA, GL_UNSIGNED_BYTE, imageData);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (int)pixelSizeToUseForTexture.width, (int)pixelSizeToUseForTexture.height, 0, format, GL_UNSIGNED_BYTE, imageData);
 
         if (self.shouldSmoothlyScaleOutput)
         {