Enable QRhi Metal backend on iOS

While we are at it, remove the Border and MirrorOnce wrap modes that have
not been supported on OpenGL, because they are unsupported with Metal+iOS
as well.

Task-number: QTBUG-78580
Change-Id: I0db94b9d3a6125b3bb5d7b1db5d02a42cd94d2c2
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

7 files changed, 59 insertions, 34 deletions

diff --git a/src/gui/rhi/qrhi.cpp b/src/gui/rhi/qrhi.cpp
index 8ef98d2e42..ac5836fc68 100644
--- a/src/gui/rhi/qrhi.cpp
+++ b/src/gui/rhi/qrhi.cpp
@@ -48,8 +48,7 @@
 #ifdef Q_OS_WIN
 #include "qrhid3d11_p_p.h"
 #endif
-//#ifdef Q_OS_DARWIN
-#ifdef Q_OS_MACOS
+#if defined(Q_OS_MACOS) || defined(Q_OS_IOS)
 #include "qrhimetal_p_p.h"
 #endif
 
@@ -2253,9 +2252,7 @@ bool QRhiTexture::buildFrom(const QRhiNativeHandles *src)
 
     \value Repeat
     \value ClampToEdge
-    \value Border
     \value Mirror
-    \value MirrorOnce
  */
 
 /*!
@@ -4049,8 +4046,7 @@ QRhi *QRhi::create(Implementation impl, QRhiInitParams *params, Flags flags, QRh
         break;
 #endif
     case Metal:
-//#ifdef Q_OS_DARWIN
-#ifdef Q_OS_MACOS
+#if defined(Q_OS_MACOS) || defined(Q_OS_IOS)
         r->d = new QRhiMetal(static_cast<QRhiMetalInitParams *>(params),
                              static_cast<QRhiMetalNativeHandles *>(importDevice));
         break;
diff --git a/src/gui/rhi/qrhi_p.h b/src/gui/rhi/qrhi_p.h
index 907924c788..8cc4c7a06c 100644
--- a/src/gui/rhi/qrhi_p.h
+++ b/src/gui/rhi/qrhi_p.h
@@ -812,9 +812,7 @@ public:
     enum AddressMode {
         Repeat,
         ClampToEdge,
-        Border,
         Mirror,
-        MirrorOnce
     };
 
     enum CompareOp {
diff --git a/src/gui/rhi/qrhid3d11.cpp b/src/gui/rhi/qrhid3d11.cpp
index 5e576e9c6a..7e05aefe8d 100644
--- a/src/gui/rhi/qrhid3d11.cpp
+++ b/src/gui/rhi/qrhid3d11.cpp
@@ -2862,12 +2862,8 @@ static inline D3D11_TEXTURE_ADDRESS_MODE toD3DAddressMode(QRhiSampler::AddressMo
         return D3D11_TEXTURE_ADDRESS_WRAP;
     case QRhiSampler::ClampToEdge:
         return D3D11_TEXTURE_ADDRESS_CLAMP;
-    case QRhiSampler::Border:
-        return D3D11_TEXTURE_ADDRESS_BORDER;
     case QRhiSampler::Mirror:
         return D3D11_TEXTURE_ADDRESS_MIRROR;
-    case QRhiSampler::MirrorOnce:
-        return D3D11_TEXTURE_ADDRESS_MIRROR_ONCE;
     default:
         Q_UNREACHABLE();
         return D3D11_TEXTURE_ADDRESS_CLAMP;
diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index abee843a74..ab61050e3e 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -1785,11 +1785,6 @@ static inline GLenum toGlWrapMode(QRhiSampler::AddressMode m)
         return GL_CLAMP_TO_EDGE;
     case QRhiSampler::Mirror:
         return GL_MIRRORED_REPEAT;
-    case QRhiSampler::MirrorOnce:
-        Q_FALLTHROUGH();
-    case QRhiSampler::Border:
-        qWarning("Unsupported wrap mode %d", m);
-        return GL_CLAMP_TO_EDGE;
     default:
         Q_UNREACHABLE();
         return GL_CLAMP_TO_EDGE;
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index 131b2da802..06e81465a2 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -41,6 +41,8 @@
 
 #ifdef Q_OS_MACOS
 #include <AppKit/AppKit.h>
+#else
+#include <UIKit/UIKit.h>
 #endif
 
 #include <Metal/Metal.h>
@@ -318,7 +320,13 @@ struct QMetalComputePipelineData
 
 struct QMetalSwapChainData
 {
+    // The iOS simulator's headers mark CAMetalLayer as iOS 13.0+ only.
+    // (for real device SDKs it is 8.0+)
+#ifdef TARGET_IPHONE_SIMULATOR
+    API_AVAILABLE(ios(13.0)) CAMetalLayer *layer = nullptr;
+#else
     CAMetalLayer *layer = nullptr;
+#endif
     id<CAMetalDrawable> curDrawable;
     dispatch_semaphore_t sem[QMTL_FRAMES_IN_FLIGHT];
     MTLRenderPassDescriptor *rp = nullptr;
@@ -1763,8 +1771,10 @@ void QRhiMetal::executeBufferHostWritesForCurrentFrame(QMetalBuffer *bufD)
         if (changeEnd == -1 || u.offset + u.data.size() > changeEnd)
             changeEnd = u.offset + u.data.size();
     }
+#ifdef Q_OS_MACOS
     if (changeBegin >= 0 && bufD->d->managed)
         [bufD->d->buf[idx] didModifyRange: NSMakeRange(NSUInteger(changeBegin), NSUInteger(changeEnd - changeBegin))];
+#endif
 
     bufD->d->pendingUpdates[idx].clear();
 }
@@ -1798,8 +1808,12 @@ void QRhiMetal::beginPass(QRhiCommandBuffer *cb,
             if (color0.needsDrawableForTex || color0.needsDrawableForResolveTex) {
                 Q_ASSERT(currentSwapChain);
                 QMetalSwapChain *swapChainD = QRHI_RES(QMetalSwapChain, currentSwapChain);
-                if (!swapChainD->d->curDrawable)
-                    swapChainD->d->curDrawable = [swapChainD->d->layer nextDrawable];
+                if (!swapChainD->d->curDrawable) {
+#ifdef TARGET_IPHONE_SIMULATOR
+                    if (@available(ios 13.0, *))
+#endif
+                        swapChainD->d->curDrawable = [swapChainD->d->layer nextDrawable];
+                }
                 if (!swapChainD->d->curDrawable) {
                     qWarning("No drawable");
                     return;
@@ -2170,12 +2184,13 @@ bool QMetalRenderBuffer::build()
     case DepthStencil:
 #ifdef Q_OS_MACOS
         desc.storageMode = MTLStorageModePrivate;
+        d->format = rhiD->d->dev.depth24Stencil8PixelFormatSupported
+                ? MTLPixelFormatDepth24Unorm_Stencil8 : MTLPixelFormatDepth32Float_Stencil8;
 #else
-        desc.storageMode = MTLResourceStorageModeMemoryless;
+        desc.storageMode = MTLStorageModeMemoryless;
         transientBacking = true;
+        d->format = MTLPixelFormatDepth32Float_Stencil8;
 #endif
-        d->format = rhiD->d->dev.depth24Stencil8PixelFormatSupported
-                ? MTLPixelFormatDepth24Unorm_Stencil8 : MTLPixelFormatDepth32Float_Stencil8;
         desc.pixelFormat = d->format;
         break;
     case Color:
@@ -2569,12 +2584,8 @@ static inline MTLSamplerAddressMode toMetalAddressMode(QRhiSampler::AddressMode
         return MTLSamplerAddressModeRepeat;
     case QRhiSampler::ClampToEdge:
         return MTLSamplerAddressModeClampToEdge;
-    case QRhiSampler::Border:
-        return MTLSamplerAddressModeClampToBorderColor;
     case QRhiSampler::Mirror:
         return MTLSamplerAddressModeMirrorRepeat;
-    case QRhiSampler::MirrorOnce:
-        return MTLSamplerAddressModeMirrorClampToEdge;
     default:
         Q_UNREACHABLE();
         return MTLSamplerAddressModeClampToEdge;
@@ -3311,7 +3322,11 @@ bool QMetalGraphicsPipeline::build()
         // validation blows up otherwise.
         MTLPixelFormat fmt = MTLPixelFormat(rpD->dsFormat);
         rpDesc.depthAttachmentPixelFormat = fmt;
+#ifdef Q_OS_MACOS
         if (fmt != MTLPixelFormatDepth16Unorm && fmt != MTLPixelFormatDepth32Float)
+#else
+        if (fmt != MTLPixelFormatDepth32Float)
+#endif
             rpDesc.stencilAttachmentPixelFormat = fmt;
     }
 
@@ -3528,6 +3543,10 @@ QMetalSwapChain::~QMetalSwapChain()
 
 void QMetalSwapChain::release()
 {
+#ifdef TARGET_IPHONE_SIMULATOR
+    if (@available(ios 13.0, *)) {
+#endif
+
     if (!d->layer)
         return;
 
@@ -3556,6 +3575,10 @@ void QMetalSwapChain::release()
     QRHI_PROF_F(releaseSwapChain(this));
 
     rhiD->unregisterResource(this);
+
+#ifdef TARGET_IPHONE_SIMULATOR
+    }
+#endif
 }
 
 QRhiCommandBuffer *QMetalSwapChain::currentFrameCommandBuffer()
@@ -3578,16 +3601,20 @@ QRhiRenderPassDescriptor *QMetalSwapChain::newCompatibleRenderPassDescriptor()
 {
     chooseFormats(); // ensure colorFormat and similar are filled out
 
-    QRHI_RES_RHI(QRhiMetal);
     QMetalRenderPassDescriptor *rpD = new QMetalRenderPassDescriptor(m_rhi);
     rpD->colorAttachmentCount = 1;
     rpD->hasDepthStencil = m_depthStencil != nullptr;
 
     rpD->colorFormat[0] = int(d->colorFormat);
 
+#ifdef Q_OS_MACOS
     // m_depthStencil may not be built yet so cannot rely on computed fields in it
+    QRHI_RES_RHI(QRhiMetal);
     rpD->dsFormat = rhiD->d->dev.depth24Stencil8PixelFormatSupported
             ? MTLPixelFormatDepth24Unorm_Stencil8 : MTLPixelFormatDepth32Float_Stencil8;
+#else
+    rpD->dsFormat = MTLPixelFormatDepth32Float_Stencil8;
+#endif
 
     return rpD;
 }
@@ -3603,6 +3630,10 @@ void QMetalSwapChain::chooseFormats()
 
 bool QMetalSwapChain::buildOrResize()
 {
+#ifdef TARGET_IPHONE_SIMULATOR
+    if (@available(ios 13.0, *)) {
+#endif
+
     Q_ASSERT(m_window);
 
     const bool needsRegistration = !window || window != m_window;
@@ -3622,7 +3653,11 @@ bool QMetalSwapChain::buildOrResize()
         return false;
     }
 
+#ifdef Q_OS_MACOS
     NSView *view = reinterpret_cast<NSView *>(window->winId());
+#else
+    UIView *view = reinterpret_cast<UIView *>(window->winId());
+#endif
     Q_ASSERT(view);
     d->layer = static_cast<CAMetalLayer *>(view.layer);
     Q_ASSERT(d->layer);
@@ -3726,6 +3761,15 @@ bool QMetalSwapChain::buildOrResize()
         rhiD->registerResource(this);
 
     return true;
+
+#ifdef TARGET_IPHONE_SIMULATOR
+    } else {
+        // Won't ever get here in a normal app because MTLDevice creation would
+        // fail too. Print a warning, just in case.
+        qWarning("No CAMetalLayer support in this version of the iOS Simulator");
+        return false;
+    }
+#endif
 }
 
 QT_END_NAMESPACE
diff --git a/src/gui/rhi/qrhivulkan.cpp b/src/gui/rhi/qrhivulkan.cpp
index 2d69abb36b..f60c2d538e 100644
--- a/src/gui/rhi/qrhivulkan.cpp
+++ b/src/gui/rhi/qrhivulkan.cpp
@@ -4617,12 +4617,8 @@ static inline VkSamplerAddressMode toVkAddressMode(QRhiSampler::AddressMode m)
         return VK_SAMPLER_ADDRESS_MODE_REPEAT;
     case QRhiSampler::ClampToEdge:
         return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
-    case QRhiSampler::Border:
-        return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER;
     case QRhiSampler::Mirror:
         return VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT;
-    case QRhiSampler::MirrorOnce:
-        return VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE;
     default:
         Q_UNREACHABLE();
         return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
diff --git a/src/gui/rhi/rhi.pri b/src/gui/rhi/rhi.pri
index 4297a5602b..ccd9592634 100644
--- a/src/gui/rhi/rhi.pri
+++ b/src/gui/rhi/rhi.pri
@@ -43,15 +43,15 @@ win32 {
     LIBS += -ld3d11 -ldxgi -ldxguid
 }
 
-# darwin {
-macos {
+macos|ios {
     HEADERS += \
         rhi/qrhimetal_p.h \
         rhi/qrhimetal_p_p.h
     SOURCES += \
         rhi/qrhimetal.mm
 
-    LIBS += -framework AppKit -framework Metal
+    macos: LIBS += -framework AppKit
+    LIBS += -framework Metal
 }
 
 include($$PWD/../../3rdparty/VulkanMemoryAllocator.pri)