framework: Metal: First pass adding MSAA support.

framework/gx-metal/metal.h

@@ -65,6 +65,7 @@ struct RenderPipelineState
  BLEND_MODE blendMode = BLEND_ALPHA;
  uint8_t colorWriteMask = 0xf;
  bool alphaToCoverageEnabled = false;
+ uint8_t msaaSampleCount = 1;
 
  GxVertexInput vertexInputs[kMaxVertexInputs] = { };
  uint8_t vertexInputCount = 0;

framework/gx-metal/metal.mm

@@ -198,7 +198,8 @@ void metal_attach(SDL_Window * window)
  initWithFrame:sdl_view.frame
  device:device
  wantsDepthBuffer:framework.enableDepthBuffer
- wantsVsync:framework.enableVsync];
+ wantsVsync:framework.enableVsync
+ msaaSampleCount:framework.msaaLevel];
 
  [sdl_view addSubview:windowData->metalview];
 
@@ -314,6 +315,9 @@ void metal_acquire_drawable()
  framework.process();
  framework.waitForEvents = false;
  }
+
+ if (activeWindowData->metalview.useMsaa == false)
+ activeWindowData->metalview.colorTexture = activeWindowData->current_drawable.texture;
 }
 
 void metal_present()
@@ -341,6 +345,9 @@ void metal_present()
 
  if (windowData->current_drawable != nullptr)
  {
+ if (windowData->metalview.useMsaa)
+ [windowData->metalview msaaResolve:windowData->current_drawable.texture];
+
  [drawablesToPresent addObject:windowData->current_drawable];
  windowData->current_drawable = nullptr;
  }
@@ -708,6 +715,8 @@ void beginRenderPass(
  int backingSx = 0;
  int backingSy = 0;
 
+ int msaaSampleCount = 1;
+
  // specify the color and depth attachment(s)
 
  for (int i = 0; i < numTargets && i < kMaxColorTargets; ++i)
@@ -731,6 +740,9 @@ void beginRenderPass(
  backingSx = colorattachment.texture.width;
  if (colorattachment.texture.height > backingSy)
  backingSy = colorattachment.texture.height;
+
+ if (colorattachment.texture.sampleCount > msaaSampleCount)
+ msaaSampleCount = colorattachment.texture.sampleCount;
  }
 
  if (depthTarget != nullptr)
@@ -748,6 +760,9 @@ void beginRenderPass(
  if (depthattachment.texture.height > backingSy)
  backingSy = depthattachment.texture.height;
 
+ if (depthattachment.texture.sampleCount > msaaSampleCount)
+ msaaSampleCount = depthattachment.texture.sampleCount;
+
  #if defined(IPHONEOS)
  if (depthattachment.texture.pixelFormat == MTLPixelFormatDepth32Float_Stencil8)
  #else
@@ -768,6 +783,8 @@ void beginRenderPass(
  pd.backingSx = backingSx;
  pd.backingSy = backingSy;
 
+ renderState.msaaSampleCount = msaaSampleCount;
+
  // begin encoding
 
  pd.encoder = [pd.cmdbuf renderCommandEncoderWithDescriptor:pd.renderdesc];
@@ -802,7 +819,7 @@ void beginRenderPass(
 
 void beginBackbufferRenderPass(const bool clearColor, const Color & color, const bool clearDepth, const float depth, const char * passName, const float backingScale)
 {
- ColorTarget colorTarget((__bridge void*)activeWindowData->current_drawable.texture);
+ ColorTarget colorTarget((__bridge void*)activeWindowData->metalview.colorTexture);
  colorTarget.setClearColor(color.r, color.g, color.b, color.a);
 
  DepthTarget depthTarget((__bridge void*)activeWindowData->metalview.depthTexture);
@@ -2145,7 +2162,7 @@ static void gxValidatePipelineState()
 
  MTLRenderPipelineDescriptor * pipelineDescriptor = [MTLRenderPipelineDescriptor new];
  pipelineDescriptor.label = [NSString stringWithCString:shaderElem.name.c_str() encoding:NSASCIIStringEncoding];
- pipelineDescriptor.sampleCount = 1;
+ pipelineDescriptor.sampleCount = renderState.msaaSampleCount;
  pipelineDescriptor.vertexFunction = vsFunction;
  pipelineDescriptor.fragmentFunction = psFunction;
  pipelineDescriptor.vertexDescriptor = vertexDescriptor;

framework/gx-metal/metalView-ns.h

@@ -30,13 +30,21 @@
 #import <Cocoa/Cocoa.h>
 #import <QuartzCore/CAMetalLayer.h>
 
+#import <Metal/MTLTexture.h>
+
 @interface MetalView : NSView
 
 @property (nonatomic, assign) CAMetalLayer *metalLayer;
 @property (nonatomic, assign) bool wantsDepthBuffer;
 
+@property (nonatomic, retain) id <MTLTexture> colorTexture;
 @property (nonatomic, retain) id <MTLTexture> depthTexture;
 
-- (instancetype)initWithFrame:(CGRect)frame device:(id <MTLDevice>)device wantsDepthBuffer:(BOOL)wantsDepthBuffer wantsVsync:(BOOL)wantsVsync;
+@property (nonatomic, assign) bool useMsaa;
+@property (nonatomic, assign) int msaaSampleCount;
+
+- (instancetype)initWithFrame:(CGRect)frame device:(id <MTLDevice>)device wantsDepthBuffer:(BOOL)wantsDepthBuffer wantsVsync:(BOOL)wantsVsync msaaSampleCount:(int)msaaSampleCount;
+
+- (void)msaaResolve:(id<MTLTexture>)texture;
 
 @end

framework/gx-metal/metalView-ns.mm

@@ -35,6 +35,8 @@
 
 #import "metalView-ns.h"
 
+#import "metal.h"
+
 #import <Cocoa/Cocoa.h>
 #import <Metal/Metal.h>
 #import <QuartzCore/CAMetalLayer.h>
@@ -56,14 +58,16 @@ - (CALayer*)makeBackingLayer
  return [self.class.layerClass layer];
 }
 
-- (instancetype)initWithFrame:(CGRect)frame device:(id <MTLDevice>)device wantsDepthBuffer:(BOOL)wantsDepthBuffer wantsVsync:(BOOL)wantsVsync
+- (instancetype)initWithFrame:(CGRect)frame device:(id <MTLDevice>)device wantsDepthBuffer:(BOOL)wantsDepthBuffer wantsVsync:(BOOL)wantsVsync msaaSampleCount:(int)msaaSampleCount
 {
  if ((self = [super initWithFrame:frame]))
  {
  self.wantsLayer = YES;
  self.autoresizingMask = NSViewWidthSizable | NSViewHeightSizable;
  self.wantsDepthBuffer = wantsDepthBuffer;
  self.depthTexture = nil;
+ self.useMsaa = msaaSampleCount > 1;
+ self.msaaSampleCount = msaaSampleCount;
 
  self.metalLayer = (CAMetalLayer *)self.layer;
  self.metalLayer.opaque = YES;
@@ -84,6 +88,34 @@ - (instancetype)initWithFrame:(CGRect)frame device:(id <MTLDevice>)device wantsD
  return self;
 }
 
+- (void)msaaResolve:(id<MTLTexture>)texture
+{
+ Assert(self.useMsaa);
+
+ @autoreleasepool
+ {
+ // resolve msaa
+
+ MTLRenderPassDescriptor * renderPassDescriptor = [MTLRenderPassDescriptor renderPassDescriptor];
+ renderPassDescriptor.colorAttachments[0].texture = self.colorTexture;
+ renderPassDescriptor.colorAttachments[0].resolveTexture = texture;
+ renderPassDescriptor.colorAttachments[0].loadAction = MTLLoadActionDontCare;
+ renderPassDescriptor.colorAttachments[0].storeAction = MTLStoreActionMultisampleResolve;
+
+ id <MTLCommandQueue> queue = metal_get_command_queue();
+
+ id <MTLCommandBuffer> cmdbuf = [queue commandBuffer];
+ {
+ id <MTLCommandEncoder> encoder = [cmdbuf renderCommandEncoderWithDescriptor:renderPassDescriptor];
+ {
+ encoder.label = @"MSAAResolve";
+ }
+ [encoder endEncoding];
+ }
+ [cmdbuf commit];
+ }
+}
+
 - (void)updateDrawableSize
 {
  NSScreen * screen = [NSScreen mainScreen];
@@ -107,14 +139,45 @@ - (void)updateDrawableSize
  {
  self.depthTexture = nullptr;
 
- MTLTextureDescriptor * descriptor = [MTLTextureDescriptor texture2DDescriptorWithPixelFormat:MTLPixelFormatDepth32Float_Stencil8 width:size.width height:size.height mipmapped:NO];
+ MTLTextureDescriptor * descriptor = [MTLTextureDescriptor new];
+ if (self.useMsaa)
+ {
+ descriptor.textureType = MTLTextureType2DMultisample;
+ descriptor.sampleCount = self.msaaSampleCount;
+ }
+ else
+ {
+ descriptor.textureType = MTLTextureType2D;
+ }
+ descriptor.pixelFormat = MTLPixelFormatDepth32Float_Stencil8;
+ descriptor.width = size.width;
+ descriptor.height = size.height;
  descriptor.resourceOptions = MTLResourceStorageModePrivate;
  descriptor.usage = MTLTextureUsageRenderTarget;
 
  self.depthTexture = [_metalLayer.device newTextureWithDescriptor:descriptor];
  }
  }
 
+ if (self.useMsaa)
+ {
+ @autoreleasepool
+ {
+ self.colorTexture = nullptr;
+
+ MTLTextureDescriptor * descriptor = [MTLTextureDescriptor new];
+ descriptor.textureType = MTLTextureType2DMultisample;
+ descriptor.sampleCount = self.msaaSampleCount;
+ descriptor.pixelFormat = self.metalLayer.pixelFormat;
+ descriptor.width = size.width;
+ descriptor.height = size.height;
+ descriptor.resourceOptions = MTLResourceStorageModePrivate;
+ descriptor.usage = MTLTextureUsageRenderTarget;
+
+ self.colorTexture = [_metalLayer.device newTextureWithDescriptor:descriptor];
+ }
+ }
+
  NSLog(@"updateDrawableSize: (%.2f x %.2f) @%.2f -> (%.2f x %.2f)",
  self.bounds.size.width,
  self.bounds.size.height,

framework/gx-metal/shader.mm

@@ -1189,7 +1189,7 @@ static void setTextureSamplerUniform(ShaderCacheElem_Metal * cacheElem, GxImmedi
 
 void Shader::setBuffer(GxImmediateIndex index, const ShaderBuffer & buffer)
 {
- not_implemented; // todo : metal : implement setBuffer
+ not_implemented; // todo : metal : implement setBuffer. note : this would require adding a "(name, index) -> vs/ps index" lookup table
 }
 
 void Shader::setBufferRw(const char * name, const ShaderBufferRw & buffer)