Get unit and render tests running on iOS simulator (#2129)

src/mbgl/mtl/offscreen_texture.cpp

@@ -35,6 +35,8 @@ public:
                 ->setUsage(MTL::TextureUsageShaderRead | MTL::TextureUsageShaderWrite | MTL::TextureUsageRenderTarget);
         }
 
+        // On iOS simulator, the depth target is PixelFormatDepth32Float_Stencil8
+#if !TARGET_OS_SIMULATOR
         if (stencil) {
             stencilTexture = context.createTexture2D();
             stencilTexture->setSize(size);
@@ -44,6 +46,8 @@ public:
             static_cast<Texture2D*>(stencilTexture.get())
                 ->setUsage(MTL::TextureUsageShaderRead | MTL::TextureUsageShaderWrite | MTL::TextureUsageRenderTarget);
         }
+#endif
+
         context.renderingStats().numFrameBuffers++;
     }
 

src/mbgl/mtl/texture2d.cpp

@@ -82,6 +82,19 @@ size_t Texture2D::numChannels() const noexcept {
 }
 
 MTL::PixelFormat Texture2D::getMetalPixelFormat() const noexcept {
+    // On iOS simulator, we need to use the combined depth/stencil format.  If the depth and stencil
+    // formats are both set on a render pipeline, they have to be identical or we'll get, e.g.:
+    //     validateWithDevice:4343: failed assertion `Render Pipeline Descriptor Validation
+    //                              depthAttachmentPixelFormat (MTLPixelFormatDepth32Float) and
+    //                              stencilAttachmentPixelFormat (MTLPixelFormatStencil8) must match.
+
+#if TARGET_OS_SIMULATOR
+    if (channelType == gfx::TextureChannelDataType::Float && pixelFormat == gfx::TexturePixelType::Depth &&
+        (usage & MTL::TextureUsageRenderTarget)) {
+        return MTL::PixelFormatDepth32Float_Stencil8;
+    }
+#endif
+
     switch (channelType) {
         case gfx::TextureChannelDataType::UnsignedByte:
             switch (pixelFormat) {
@@ -138,6 +151,24 @@ void Texture2D::createMetalTexture() noexcept {
     if (auto textureDescriptor = NS::RetainPtr(
             MTL::TextureDescriptor::texture2DDescriptor(format, size.width, size.height, /*mipmapped=*/false))) {
         textureDescriptor->setUsage(usage);
+#if TARGET_OS_SIMULATOR
+        switch (format) {
+            case MTL::PixelFormatDepth16Unorm:
+            case MTL::PixelFormatDepth32Float:
+            case MTL::PixelFormatStencil8:
+            case MTL::PixelFormatDepth24Unorm_Stencil8:
+            case MTL::PixelFormatDepth32Float_Stencil8:
+            case MTL::PixelFormatX32_Stencil8:
+            case MTL::PixelFormatX24_Stencil8:
+                // On iOS simulator, the default shared mode is invalid for depth and stencil textures.
+                //  'Texture Descriptor Validation MTLTextureDescriptor: Depth, Stencil, DepthStencil
+                //   textures cannot be allocated with MTLStorageModeShared on this device.
+                textureDescriptor->setStorageMode(MTL::StorageMode::StorageModePrivate);
+                break;
+            default:
+                break;
+        }
+#endif
         metalTexture = context.createMetalTexture(std::move(textureDescriptor));
     }
 

test/include/mbgl/test/util.hpp

@@ -6,7 +6,8 @@
 
 #define TEST_READ_ONLY 0
 
-#if !ANDROID
+// iOS simulator server can work if port 3000 is available
+#if !ANDROID && !TARGET_OS_SIMULATOR
 #ifndef TEST_HAS_SERVER
 #define TEST_HAS_SERVER 1
 #endif

test/map/map.test.cpp

@@ -8,7 +8,6 @@
 #include <mbgl/gfx/backend_scope.hpp>
 #include <mbgl/gfx/headless_frontend.hpp>
 #include <mbgl/gfx/shader_registry.hpp>
-#include <mbgl/gl/context.hpp>
 #include <mbgl/map/map_options.hpp>
 #include <mbgl/math/log2.hpp>
 #include <mbgl/renderer/renderer.hpp>