Add MSAA option to SampleApp

Review URL: http://codereview.appspot.com/5969049


git-svn-id: http://skia.googlecode.com/svn/trunk@3627 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 24 insertions, 12 deletions

diff --git a/src/views/mac/SkNSView.mm b/src/views/mac/SkNSView.mm
index 30488abb3d..1e7be69cab 100644
--- a/src/views/mac/SkNSView.mm
+++ b/src/views/mac/SkNSView.mm
@@ -226,25 +226,36 @@ static SkKey raw2key(UInt32 raw)
 #include <OpenGL/OpenGL.h>
 
 namespace { 
-CGLContextObj createGLContext() {
+CGLContextObj createGLContext(int msaaSampleCount) {
     GLint major, minor;
     CGLGetVersion(&major, &minor);
     
-    const CGLPixelFormatAttribute attributes[] = {
-        kCGLPFAStencilSize, (CGLPixelFormatAttribute)8,
-#if USE_MSAA
-        kCGLPFASampleBuffers, 1,
-        kCGLPFAMultisample,
-        kCGLPFASamples, 8,
-#endif
+    static const CGLPixelFormatAttribute attributes[] = {
+        kCGLPFAStencilSize, (CGLPixelFormatAttribute) 8,
         kCGLPFAAccelerated,
         kCGLPFADoubleBuffer,
         (CGLPixelFormatAttribute)0
     };
     
     CGLPixelFormatObj format;
-    GLint npix;
-    CGLChoosePixelFormat(attributes, &format, &npix);
+    GLint npix = 0;
+    if (msaaSampleCount > 0) {
+        static int kAttributeCount = SK_ARRAY_COUNT(attributes);
+        CGLPixelFormatAttribute msaaAttributes[kAttributeCount + 5];
+        memcpy(msaaAttributes, attributes, sizeof(attributes));
+        SkASSERT(0 == msaaAttributes[kAttributeCount - 1]);
+        msaaAttributes[kAttributeCount - 1] = kCGLPFASampleBuffers;
+        msaaAttributes[kAttributeCount + 0] = (CGLPixelFormatAttribute)1;
+        msaaAttributes[kAttributeCount + 1] = kCGLPFAMultisample;
+        msaaAttributes[kAttributeCount + 2] = kCGLPFASamples;
+        msaaAttributes[kAttributeCount + 3] =
+                                    (CGLPixelFormatAttribute)msaaSampleCount;
+        msaaAttributes[kAttributeCount + 4] = (CGLPixelFormatAttribute)0;
+        CGLChoosePixelFormat(msaaAttributes, &format, &npix);
+    }
+    if (!npix) {
+        CGLChoosePixelFormat(attributes, &format, &npix);
+    }
     
     CGLContextObj ctx;
     CGLCreateContext(format, NULL, &ctx);
@@ -267,9 +278,10 @@ CGLContextObj createGLContext() {
         [fGLContext setView:self];
     }
 }
-- (bool)attach:(SkOSWindow::SkBackEndTypes)attachType {
+- (bool)attach:(SkOSWindow::SkBackEndTypes)attachType
+        withMSAASampleCount:(int) sampleCount {
     if (nil == fGLContext) {
-        CGLContextObj ctx = createGLContext();
+        CGLContextObj ctx = createGLContext(sampleCount);
         fGLContext = [[NSOpenGLContext alloc] initWithCGLContextObj:ctx];
         CGLReleaseContext(ctx);
         if (NULL == fGLContext) {