redo metal presentation

projects/apis/metal/src/devices/metal_output_device.m

@@ -4,12 +4,60 @@
 #include "instance/metal_instance.h"
 #include "instance/gryphn_instance.h"
 
+#include "metal_shader.msl"
+
 gnReturnCode createMetalOutputDevice(gnInstanceHandle instance, gnOutputDeviceHandle outputDevice, gnOutputDeviceInfo deviceInfo) {
     if (instance == GN_NULL_HANDLE) return GN_INVALID_HANDLE;
 
     outputDevice->outputDevice = malloc(sizeof(gnPlatformOutputDevice));
     outputDevice->outputDevice->device = deviceInfo.physicalDevice->physicalDevice->device.retain;
     outputDevice->outputDevice->transferQueue = outputDevice->outputDevice->device.newCommandQueue;
+
+    // create full screen quad
+    float verticies[] = {
+        -1.0f, -1.0f, 0.0f, 1.0f,
+         1.0f, -1.0f, 1.0f, 1.0f,
+        -1.0f,  1.0f, 0.0f, 0.0f,
+         1.0f,  1.0f, 1.0f, 0.0f,
+    };
+    outputDevice->outputDevice->fullScreenQuadBuffer =
+        [outputDevice->outputDevice->device
+            newBufferWithBytes:verticies
+            length:sizeof(verticies)
+            options:MTLResourceStorageModeShared
+        ];
+
+    NSError *error = nil;
+    outputDevice->outputDevice->fullScreenShader = [outputDevice->outputDevice->device
+        newLibraryWithSource:@(shader_source)
+        options:nil
+        error:&error
+    ];
+    if (!outputDevice->outputDevice->fullScreenShader) {
+        gnDebuggerSetErrorMessage(instance->debugger, (gnMessageData){
+            .message = gnCombineStrings(gnCreateString("Failed to create shader for output device: \n"), error.localizedDescription.UTF8String)
+        });
+        return GN_DEVICE_LOST;
+    }
+
+    outputDevice->outputDevice->fullScreenVertex = [outputDevice->outputDevice->fullScreenShader newFunctionWithName:@"fullscreen_vertex"];
+    outputDevice->outputDevice->fullScreenFragment = [outputDevice->outputDevice->fullScreenShader newFunctionWithName:@"fullscreen_fragment"];
+
+    MTLRenderPipelineDescriptor *pipelineDesc = [[MTLRenderPipelineDescriptor alloc] init];
+    pipelineDesc.vertexFunction = outputDevice->outputDevice->fullScreenVertex;
+    pipelineDesc.fragmentFunction = outputDevice->outputDevice->fullScreenFragment;
+    pipelineDesc.colorAttachments[0].pixelFormat = MTLPixelFormatBGRA8Unorm_sRGB;
+    pipelineDesc.depthAttachmentPixelFormat = MTLPixelFormatInvalid;
+    pipelineDesc.stencilAttachmentPixelFormat = MTLPixelFormatInvalid;
+
+    outputDevice->outputDevice->fullScreenPipeline = [outputDevice->outputDevice->device newRenderPipelineStateWithDescriptor:pipelineDesc error:&error];
+    if (!outputDevice->outputDevice->fullScreenPipeline) {
+        gnDebuggerSetErrorMessage(instance->debugger, (gnMessageData){
+            .message = gnCombineStrings(gnCreateString("Failed to create graphics pipeline for output device: \n"), error.localizedDescription.UTF8String)
+        });
+        return GN_DEVICE_LOST;
+    }
+
     return GN_SUCCESS;
 }
 
@@ -20,6 +68,13 @@ void waitForMetalDevice(gnOutputDeviceHandle device) {
 void destroyMetalOutputDevice(gnOutputDeviceHandle device) {
     [device->outputDevice->transferQueue release];
     [device->outputDevice->device release];
+
+    [device->outputDevice->fullScreenQuadBuffer release];
+    [device->outputDevice->fullScreenShader release];
+    [device->outputDevice->fullScreenVertex release];
+    [device->outputDevice->fullScreenFragment release];
+    [device->outputDevice->fullScreenPipeline release];
+
     free(device->outputDevice);
 }
 

projects/apis/metal/src/devices/metal_output_devices.h

@@ -14,6 +14,11 @@ struct gnPlatformOutputDevice_t {
 
     id<MTLCommandBuffer> executingCommandBuffer;
     id<MTLCommandQueue> transferQueue;
+
+    id<MTLBuffer> fullScreenQuadBuffer;
+    id<MTLLibrary> fullScreenShader;
+    id<MTLFunction> fullScreenVertex, fullScreenFragment;
+    id<MTLRenderPipelineState> fullScreenPipeline;
 } gnPlatformOutputDevice;
 
 gnPhysicalDevice* getMetalDevices(gnInstanceHandle instance, uint32_t* deviceCount);

projects/apis/metal/src/devices/metal_shader.msl

@@ -0,0 +1,26 @@
+const char* shader_source =
+"using namespace metal;"
+""
+"struct Vertex {"
+"    float2 position;"
+"    float2 texcoord;"
+"};"
+""
+"struct VertexOut {"
+"    float4 position [[position]];"
+"    float2 texcoord;"
+"};"
+""
+"vertex VertexOut fullscreen_vertex(const device Vertex* vertices [[buffer(0)]],"
+"                                   uint vid [[vertex_id]]) {"
+"    VertexOut out;"
+"    out.position = float4(vertices[vid].position, 0.0, 1.0);"
+"    out.texcoord = vertices[vid].texcoord;"
+"    return out;"
+"}"
+""
+"fragment float4 fullscreen_fragment(VertexOut in [[stage_in]],"
+"                                    texture2d<float> tex [[texture(0)]]) {"
+"    constexpr sampler s(address::clamp_to_edge, filter::linear);"
+"    return tex.sample(s, in.texcoord);"
+"}";