Basic Metal support. No OpenGL fallback, no shaders, no blending.

Cocoa/GBView.m

@@ -1,6 +1,7 @@
 #import <Carbon/Carbon.h>
 #import "GBView.h"
 #import "GBViewGL.h"
+#import "GBViewMetal.h"
 #import "GBButtons.h"
 #import "NSString+StringForKey.h"
 
@@ -19,16 +20,13 @@
 
 + (instancetype)alloc
 {
-    if (self == [GBView class]) {
-        return [GBViewGL alloc];
-    }
-    return [super alloc];
+    return [self allocWithZone:NULL];
 }
 
 + (instancetype)allocWithZone:(struct _NSZone *)zone
 {
     if (self == [GBView class]) {
-        return [GBViewGL allocWithZone: zone];
+        return [GBViewMetal allocWithZone: zone];
     }
     return [super allocWithZone:zone];
 }

Cocoa/GBViewMetal.h

@@ -0,0 +1,7 @@
+#import <Cocoa/Cocoa.h>
+#import <MetalKit/MetalKit.h>
+#import "GBView.h"
+
+@interface GBViewMetal : GBView<MTKViewDelegate>
+
+@end

Cocoa/GBViewMetal.m

@@ -0,0 +1,131 @@
+#import "GBViewMetal.h"
+
+#define WIDTH 160
+#define HEIGHT 144
+#define PITCH (160 * 4)
+
+static const MTLRegion region = {
+    {0, 0, 0},         // MTLOrigin
+    {WIDTH, HEIGHT, 1} // MTLSize
+};
+
+static const vector_float2 rect[] =
+{
+    {-1, -1},
+    { 1, -1},
+    {-1,  1},
+    { 1,  1},
+};
+
+@implementation GBViewMetal
+{
+    id<MTLDevice> device;
+    id<MTLTexture> texture, previous_texture;
+    id<MTLBuffer> vertices;
+    id<MTLRenderPipelineState> pipeline_state;
+    id<MTLCommandQueue> command_queue;
+}
+
+- (void)createInternalView
+{
+    MTKView *view = [[MTKView alloc] initWithFrame:self.frame device:(device = MTLCreateSystemDefaultDevice())];
+    view.delegate = self;
+    self.internalView = view;
+    
+    MTLTextureDescriptor *texture_descriptor = [[MTLTextureDescriptor alloc] init];
+    
+    texture_descriptor.pixelFormat = MTLPixelFormatRGBA8Unorm;
+    
+    texture_descriptor.width = WIDTH;
+    texture_descriptor.height = HEIGHT;
+    
+    texture = [device newTextureWithDescriptor:texture_descriptor];
+    previous_texture = [device newTextureWithDescriptor:texture_descriptor];
+    
+    vertices = [device newBufferWithBytes:rect
+                                   length:sizeof(rect)
+                                  options:MTLResourceStorageModeShared];
+
+    [self loadShader];
+}
+
+- (void) loadShader
+{
+    NSError *error = nil;
+    NSString *shader_source = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"MasterShader"
+                                                                                                 ofType:@"metal"
+                                                                                            inDirectory:@"Shaders"]
+                                                        encoding:NSUTF8StringEncoding
+                                                           error:nil];
+    id<MTLLibrary> library = [device newLibraryWithSource:shader_source
+                                                   options:nil
+                                                     error:&error];
+    if (error) {
+        NSLog(@"Error: %@", error);
+    }
+    
+    id<MTLFunction> vertex_function = [library newFunctionWithName:@"vertex_shader"];
+    id<MTLFunction> fragment_function = [library newFunctionWithName:@"fragment_shader"];
+    
+    // Set up a descriptor for creating a pipeline state object
+    MTLRenderPipelineDescriptor *pipeline_state_descriptor = [[MTLRenderPipelineDescriptor alloc] init];
+    pipeline_state_descriptor.vertexFunction = vertex_function;
+    pipeline_state_descriptor.fragmentFunction = fragment_function;
+    pipeline_state_descriptor.colorAttachments[0].pixelFormat = ((MTKView *)self.internalView).colorPixelFormat;
+    
+    error = nil;
+    pipeline_state = [device newRenderPipelineStateWithDescriptor:pipeline_state_descriptor
+                                                             error:&error];
+    if (error)  {
+        NSLog(@"Failed to created pipeline state, error %@", error);
+    }
+    
+    command_queue = [device newCommandQueue];
+}
+
+- (void)mtkView:(nonnull MTKView *)view drawableSizeWillChange:(CGSize)size
+{
+}
+
+- (void)drawInMTKView:(nonnull MTKView *)view
+{
+    [texture replaceRegion:region
+               mipmapLevel:0
+                 withBytes:[self currentBuffer]
+               bytesPerRow:PITCH];
+    
+    MTLRenderPassDescriptor *render_pass_descriptor = view.currentRenderPassDescriptor;
+    id<MTLCommandBuffer> command_buffer = [command_queue commandBuffer];
+
+    if(render_pass_descriptor != nil)
+    {
+        id<MTLRenderCommandEncoder> render_encoder =
+            [command_buffer renderCommandEncoderWithDescriptor:render_pass_descriptor];
+        
+        [render_encoder setViewport:(MTLViewport){0.0, 0.0,
+            view.bounds.size.width * view.window.backingScaleFactor,
+            view.bounds.size.height * view.window.backingScaleFactor,
+            -1.0, 1.0}];
+        
+        [render_encoder setRenderPipelineState:pipeline_state];
+        
+        [render_encoder setVertexBuffer:vertices
+                                 offset:0
+                                atIndex:0];
+        
+        [render_encoder setFragmentTexture:texture
+                                  atIndex:0];
+        
+        [render_encoder drawPrimitives:MTLPrimitiveTypeTriangleStrip
+                          vertexStart:0
+                          vertexCount:4];
+        
+        [render_encoder endEncoding];
+        
+        [command_buffer presentDrawable:view.currentDrawable];
+    }
+    
+    
+    [command_buffer commit];
+}
+@end

Makefile

@@ -61,7 +61,7 @@ ifeq ($(PLATFORM),Darwin)
 SYSROOT := $(shell xcodebuild -sdk macosx -version Path 2> /dev/null)
 CFLAGS += -F/Library/Frameworks
 OCFLAGS += -x objective-c -fobjc-arc -Wno-deprecated-declarations -isysroot $(SYSROOT) -mmacosx-version-min=10.9
-LDFLAGS += -framework AppKit -framework PreferencePanes -framework Carbon -framework QuartzCore
+LDFLAGS += -framework AppKit -framework PreferencePanes -framework Carbon -framework QuartzCore -framework Metal -framework MetalKit
 SDL_LDFLAGS := -F/Library/Frameworks -framework SDL2 -framework OpenGL
 endif
 CFLAGS += -Wno-deprecated-declarations
@@ -160,8 +160,6 @@ $(OBJ)/%.m.o: %.m
 
 # Cocoa Port
 
-Shaders:$(shell ls Shaders/*.fsh)
-
 $(BIN)/SameBoy.app: $(BIN)/SameBoy.app/Contents/MacOS/SameBoy \
                     $(shell ls Cocoa/*.icns) \
                     Cocoa/License.html \
@@ -178,7 +176,7 @@ $(BIN)/SameBoy.app: $(BIN)/SameBoy.app/Contents/MacOS/SameBoy \
 	sed s/@VERSION/$(VERSION)/ < Cocoa/Info.plist > $(BIN)/SameBoy.app/Contents/Info.plist
 	cp Cocoa/License.html $(BIN)/SameBoy.app/Contents/Resources/Credits.html
 	$(MKDIR) -p $(BIN)/SameBoy.app/Contents/Resources/Shaders
-	cp Shaders/*.fsh $(BIN)/SameBoy.app/Contents/Resources/Shaders
+	cp Shaders/*.fsh Shaders/*.metal $(BIN)/SameBoy.app/Contents/Resources/Shaders
 	$(MKDIR) -p $(BIN)/SameBoy.app/Contents/Library/QuickLook/
 	cp -rf $(BIN)/SameBoy.qlgenerator $(BIN)/SameBoy.app/Contents/Library/QuickLook/
 
@@ -289,7 +287,7 @@ $(BIN)/SDL/background.bmp: SDL/background.bmp
 
 $(BIN)/SDL/Shaders: Shaders
 	-@$(MKDIR) -p $(dir $@)
-	cp -rf $^ $@
+	cp -rf Shaders/*.fsh $@
 
 # Boot ROMs
 

Shaders/MasterShader.metal

@@ -0,0 +1,45 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_math>
+
+using namespace metal;
+
+/* For GLSL compatibility */
+typedef float2 vec2;
+typedef float3 vec3;
+typedef float4 vec4;
+
+typedef struct {
+    float4 position [[position]];
+    float2 texcoords;
+} rasterizer_data;
+
+// Vertex Function
+vertex rasterizer_data vertex_shader(uint index [[ vertex_id ]],
+                                     constant vector_float2 *vertices [[ buffer(0) ]])
+
+{
+    rasterizer_data out;
+
+    out.position.xy = vertices[index].xy;
+    out.position.z = 0.0;
+    out.position.w = 1.0;
+    out.texcoords = (vertices[index].xy + float2(1, 1)) / 2.0;
+
+    return out;
+}
+
+
+static inline float4 texture(texture2d<half> texture, float2 pos)
+{
+    constexpr sampler texture_sampler;
+    return float4(texture.sample(texture_sampler, pos));
+}
+
+fragment float4 fragment_shader(rasterizer_data in [[stage_in]],
+                                texture2d<half> image [[ texture(0) ]])
+{
+    in.texcoords.y = 1 - in.texcoords.y;
+    return texture(image, in.texcoords);
+}
+