[Metal] Fixed crash in Metal PSO creation when invalid shaders are pr…

…ovided.

LLGL should no longer throw an exception on PSO creation failure.
This replaces the old behavior in the Metal backend with the error report like in the other baackends.

sources/Renderer/Metal/RenderState/MTComputePSO.mm

@@ -25,11 +25,17 @@
  /* Get native shader functions */
  computeShader_ = LLGL_CAST(const MTShader*, desc.computeShader);
  if (!computeShader_)
- throw std::invalid_argument("cannot create Metal compute pipeline without compute shader");
+ {
+ GetMutableReport().Errorf("cannot create Metal compute pipeline without compute shader");
+ return;
+ }
 
  id<MTLFunction> kernelFunc = computeShader_->GetNative();
  if (!kernelFunc)
- throw std::invalid_argument("cannot create Metal compute pipeline without valid compute kernel function");
+ {
+ GetMutableReport().Errorf("cannot create Metal compute pipeline without valid compute kernel function");
+ return;
+ }
 
  /* Create native compute pipeline state */
  NSError* error = nullptr;

sources/Renderer/Metal/RenderState/MTGraphicsPSO.h

@@ -91,7 +91,7 @@ class MTGraphicsPSO final : public MTPipelineState
 
  private:
 
- void CreateRenderPipelineState(
+ bool CreateRenderPipelineState(
  id<MTLDevice> device,
  const GraphicsPipelineDescriptor& desc,
  const MTRenderPass* defaultRenderPass

sources/Renderer/Metal/RenderState/MTGraphicsPSO.mm

@@ -74,9 +74,11 @@ static void FillDefaultMTStencilDesc(MTLStencilDescriptor* dst)
  blendColor_[3] = desc.blend.blendFactor[3];
 
  /* Create render pipeline and depth-stencil states */
- CreateRenderPipelineState(device, desc, defaultRenderPass);
- CreateDepthStencilState(device, desc);
- BuildStaticStateBuffer(desc);
+ if (CreateRenderPipelineState(device, desc, defaultRenderPass))
+ {
+ CreateDepthStencilState(device, desc);
+ BuildStaticStateBuffer(desc);
+ }
 }
 
 void MTGraphicsPSO::Bind(id<MTLRenderCommandEncoder> renderEncoder)
@@ -202,7 +204,7 @@ static void FillColorAttachmentDesc(
  return vertexShaderMT;
 }
 
-void MTGraphicsPSO::CreateRenderPipelineState(
+bool MTGraphicsPSO::CreateRenderPipelineState(
  id<MTLDevice> device,
  const GraphicsPipelineDescriptor& desc,
  const MTRenderPass* defaultRenderPass)
@@ -214,7 +216,16 @@ static void FillColorAttachmentDesc(
  numPatchControlPoints_ = vertexShaderMT->GetNumPatchControlPoints();
 
  if (id<MTLFunction> vertexFunc = vertexShaderMT->GetNative())
+ {
+ /* Cache patch type of vertex function */
  patchType_ = [vertexFunc patchType];
+ }
+ else
+ {
+ /* Error: Every graphics PSO needs a valid vertex function */
+ GetMutableReport().Errorf("cannot create Metal graphics PSO without valid vertex function");
+ return false;
+ }
 
  /* Get render pass object */
  const MTRenderPass* renderPassMT = nullptr;
@@ -288,6 +299,8 @@ static void FillColorAttachmentDesc(
  else
  throw std::invalid_argument("cannot create Metal tessellation pipeline without tessellation compute shader");
  }
+
+ return true;
 }
 
 id<MTLRenderPipelineState> MTGraphicsPSO::CreateNativeRenderPipelineState(