Add legacy NSView support

NSView is used in preference to CALayer if available, as we avoid all the
framebuffer blitting overhead.

gl-natives/src/main/c/jaggl.c

@@ -27,14 +27,18 @@
 #include <stdlib.h>
 
 #if defined(__APPLE__) && defined(__MACH__)
-#define _JAGGL_JAWT_VERSION (JAWT_VERSION_1_4 | JAWT_MACOSX_USE_CALAYER)
+#define _JAGGL_GET(env) \
+	JAWT awt = { .version = JAWT_VERSION_1_4 }; \
+	bool awt_valid = JAWT_GetAWT(env, &awt); \
+	if (!awt_valid) { \
+		awt.version |= JAWT_MACOSX_USE_CALAYER; \
+		awt_valid = JAWT_GetAWT(env, &awt); \
+	}
 #else
-#define _JAGGL_JAWT_VERSION JAWT_VERSION_1_4
-#endif
-
 #define _JAGGL_GET(env) \
-	JAWT awt = { .version = (jint) _JAGGL_JAWT_VERSION }; \
+	JAWT awt = { .version = JAWT_VERSION_1_4 }; \
 	bool awt_valid = JAWT_GetAWT(env, &awt);
+#endif
 
 #define _JAGGL_GET_AND_LOCK(env) \
 	_JAGGL_GET(env); \
@@ -126,6 +130,11 @@ static HWND jaggl_window;
 static HDC jaggl_device;
 static HGLRC jaggl_context;
 #elif defined(__APPLE__) && defined(__MACH__)
+/* copy of JAWT_MacOSXDrawingSurfaceInfo from Java 6's jawt_md.h */
+struct jaggl_legacy_dsi {
+	NSView *view;
+};
+
 @interface JagGLLayer : CAOpenGLLayer
 {
 	@private
@@ -136,6 +145,7 @@ static HGLRC jaggl_context;
 }
 @end
 
+static bool jaggl_calayer;
 static CGLContextObj jaggl_onscreen_context;
 static CGLContextObj jaggl_context;
 static CGLPixelFormatObj jaggl_pix;
@@ -697,6 +707,7 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_destroy(JNIEnv *env, jclass cls) {
 			jaggl_context_appkit = NULL;
 		}
 
+		if (jaggl_calayer) {
 			if (jaggl_view) {
 				[jaggl_view release];
 				jaggl_view = NULL;
@@ -712,9 +723,10 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_destroy(JNIEnv *env, jclass cls) {
 				[jaggl_layer release];
 				jaggl_layer = NULL;
 			}
+		}
 	});
 
-	if (jaggl_onscreen_context) {
+	if (jaggl_calayer && jaggl_onscreen_context) {
 		CGLDestroyContext(jaggl_onscreen_context);
 		jaggl_onscreen_context = NULL;
 	}
@@ -750,7 +762,9 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_swapBuffers(JNIEnv *env, jclass cl
 #elif defined(_WIN32)
 	result = (jboolean) SwapBuffers(jaggl_device);
 #elif defined(__APPLE__) && defined(__MACH__)
+	if (jaggl_calayer) {
 		[jaggl_layer blit];
+	}
 
 	/*
 	 * This buffer swap isn't strictly necessary (in fact, I'm not sure if we
@@ -796,7 +810,9 @@ JNIEXPORT void JNICALL Java_jaggl_context_setSwapInterval(JNIEnv *env, jclass cl
 #elif defined(__APPLE__) && defined(__MACH__)
 	GLint param = (GLint) interval;
 	CGLSetParameter(jaggl_context, kCGLCPSwapInterval, &param);
+	if (jaggl_calayer) {
 		CGLSetParameter(jaggl_onscreen_context, kCGLCPSwapInterval, &param);
+	}
 #else
 #error Unsupported platform
 #endif
@@ -1066,11 +1082,12 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_choosePixelFormat1(JNIEnv *env, jc
 
 	result = JNI_TRUE;
 #elif defined(__APPLE__) && defined(__MACH__)
-	id<JAWT_SurfaceLayers> platformInfo = (id<JAWT_SurfaceLayers>) dsi->platformInfo;
-	if (!platformInfo) {
+	if (!dsi->platformInfo) {
 		goto dsi_free;
 	}
 
+	jaggl_calayer = awt.version & (jint) JAWT_MACOSX_USE_CALAYER;
+
 	for (int i = 0; i < 2; i++) {
 		bool double_buffered = i == 0;
 
@@ -1109,6 +1126,9 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_choosePixelFormat1(JNIEnv *env, jc
 		jaggl_double_buffered = double_buffered;
 		jaggl_alpha_bits = alpha_bits;
 
+		if (jaggl_calayer) {
+			id<JAWT_SurfaceLayers> platformInfo = (id<JAWT_SurfaceLayers>) dsi->platformInfo;
+
 			CGLCreateContext(jaggl_pix, NULL, &jaggl_onscreen_context);
 			if (!jaggl_onscreen_context) {
 				CGLDestroyPixelFormat(jaggl_pix);
@@ -1137,6 +1157,10 @@ JNIEXPORT jboolean JNICALL Java_jaggl_context_choosePixelFormat1(JNIEnv *env, jc
 				jaggl_layer.frame = NSMakeRect(x, platformInfo.windowLayer.bounds.size.height - y - dsi->bounds.height, dsi->bounds.width, dsi->bounds.height);
 				[jaggl_layer setNeedsDisplay];
 			});
+		} else {
+			struct jaggl_legacy_dsi *platformInfo = (struct jaggl_legacy_dsi *) dsi->platformInfo;
+			jaggl_view = platformInfo->view;
+		}
 
 		result = JNI_TRUE;
 		goto dsi_free;