MTLSwapchain.mm

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 Copyright (c) 2021 Xiamen Yaji Software Co., Ltd.

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#import "../gfx-base/GFXDef-common.h"
#import "MTLSwapchain.h"
#if CC_PLATFORM == CC_PLATFORM_MAC_OSX
    #import <AppKit/NSView.h>
#else
    #import <UIKit/UIView.h>
#endif

#import "MTLGPUObjects.h"
#import "MTLDevice.h"
#import "MTLGPUObjects.h"
namespace cc {
namespace gfx {

namespace {
#if CC_PLATFORM == CC_PLATFORM_MAC_OSX
    using CCView = NSView;
#else
    using CCView = UIView;
#endif
};

CCMTLSwapchain::CCMTLSwapchain() {
}

CCMTLSwapchain::~CCMTLSwapchain() {
    destroy();
}

void CCMTLSwapchain::doInit(const SwapchainInfo &info) {
    _gpuSwapchainObj = CC_NEW(CCMTLGPUSwapChainObject);

    //----------------------acquire layer-----------------------------------
    auto* view = (CCView*)info.windowHandle;
    CAMetalLayer *layer = static_cast<CAMetalLayer *>(view.layer);

    if (layer.pixelFormat == MTLPixelFormatInvalid) {
        layer.pixelFormat = MTLPixelFormatBGRA8Unorm;
    }
    layer.framebufferOnly = NO;
    //setDisplaySyncEnabled : physic device refresh rate.
    //setPresentsWithTransaction : Core Animation transactions update rate.
    switch (_vsyncMode) {
        case VsyncMode::OFF:
            [layer setDisplaySyncEnabled:NO];
            [layer setPresentsWithTransaction:NO];
            break;
        case VsyncMode::ON:
            [layer setDisplaySyncEnabled:YES];
            [layer setPresentsWithTransaction:YES];
        case VsyncMode::RELAXED:
        case VsyncMode::MAILBOX:
        case VsyncMode::HALF:
            [layer setDisplaySyncEnabled:YES];
            [layer setPresentsWithTransaction:NO];
        default:
            break;
    }
    _gpuSwapchainObj->mtlLayer = layer;

//    MTLPixelFormatBGRA8Unorm
//    MTLPixelFormatBGRA8Unorm_sRGB
//    MTLPixelFormatRGBA16Float
//    MTLPixelFormatRGB10A2Unorm (macOS only)
//    MTLPixelFormatBGR10A2Unorm (macOS only)
//    MTLPixelFormatBGRA10_XR
//    MTLPixelFormatBGRA10_XR_sRGB
//    MTLPixelFormatBGR10_XR
//    MTLPixelFormatBGR10_XR_sRGB
    Format colorFmt        = Format::BGRA8;
    Format depthStencilFmt = Format::DEPTH_STENCIL;

    _colorTexture = CC_NEW(CCMTLTexture);
    _depthStencilTexture = CC_NEW(CCMTLTexture);

    SwapchainTextureInfo textureInfo;
    textureInfo.swapchain = this;
    textureInfo.format    = colorFmt;
    textureInfo.width     = info.width;
    textureInfo.height    = info.height;
    initTexture(textureInfo, _colorTexture);

    textureInfo.format = depthStencilFmt;
    initTexture(textureInfo, _depthStencilTexture);

    CCMTLDevice::getInstance()->registerSwapchain(this);
}

void CCMTLSwapchain::doDestroy(){
    CCMTLDevice::getInstance()->unRegisterSwapchain(this);
    if(_gpuSwapchainObj) {
        _gpuSwapchainObj->currentDrawable = nil;
        _gpuSwapchainObj->mtlLayer = nil;

        CC_SAFE_DELETE(_gpuSwapchainObj);
    }

    if(_colorTexture) {
        CC_SAFE_DESTROY(_colorTexture);
    }

    if(_depthStencilTexture) {
        CC_SAFE_DESTROY(_depthStencilTexture);
    }
}

void CCMTLSwapchain::doDestroySurface() {
    if(_gpuSwapchainObj) {
        _gpuSwapchainObj->currentDrawable = nil;
        _gpuSwapchainObj->mtlLayer = nil;
    }
}

void CCMTLSwapchain::doResize(uint32_t width, uint32_t height, SurfaceTransform /*transform*/) {
    _colorTexture->resize(width, height);
    _depthStencilTexture->resize(width, height);
}

CCMTLTexture* CCMTLSwapchain::colorTexture() {
    return static_cast<CCMTLTexture*>(_colorTexture);
}

CCMTLTexture* CCMTLSwapchain::depthStencilTexture() {
    return static_cast<CCMTLTexture*>(_depthStencilTexture);
}

id<CAMetalDrawable> CCMTLSwapchain::currentDrawable() {
    return _gpuSwapchainObj->currentDrawable;
}

void CCMTLSwapchain::release() {
    _gpuSwapchainObj->currentDrawable = nil;
    static_cast<CCMTLTexture*>(_colorTexture)->update();
}

void CCMTLSwapchain::acquire() {
    // hang on here if next drawable not available
    while(!_gpuSwapchainObj->currentDrawable) {
        _gpuSwapchainObj->currentDrawable = [_gpuSwapchainObj->mtlLayer nextDrawable] ;
        static_cast<CCMTLTexture*>(_colorTexture)->update();
    }
}

void CCMTLSwapchain::doCreateSurface(void *windowHandle) {

}

}
}