Rethinking a engine structure

[Try]

Things to do:

• [x] Split VectorImage into VectorImage, as CPU data + VectorImage::Mesh, as GPU data.
• [x] Rename Uniforms to something else, probably DescriptorSet
• [ ] Add readable depth texture

Things to think about:

• [x] Implement Metal-api
• [ ] Reconsider design cross-queue/cpu synchronization
• [ ] Investigate usefulness of VK_EXT_inline_uniform_block

[Try]

synchronization: Metal model look quite promising:

CommandBuffer cmd;
...
cmd.addCompletionHandler([]() {

  });
cmd.wait();

Can be done naively in Metal; By Timeline Semaphore + extra thread on Vulka/Dx12

[Try]

Wanna rethink framebuffer/renderpass api.

Goal:

1. Simplify usage
2. Add support for resolve attachment(msaa)
3. Add support for density-map and vrs-attachment

Current syntax:

fboGBuf     = device.frameBuffer(lightingBuf,gbufDiffuse,gbufNormal,gbufDepth,zbuffer);
gbufPass    = device.pass(FboMode(FboMode::PreserveOut,Color(0.0)),
                          FboMode(FboMode::PreserveOut),
                          FboMode(FboMode::PreserveOut),
                          FboMode(FboMode::PreserveOut,Color(1.0)),
                          FboMode(FboMode::PreserveOut,1.f));

'Good' metal example

desc.colorAttachments[0].texture     = tex;
desc.colorAttachments[0].loadAction  = MTLLoadActionClear;
desc.colorAttachments[0].clearColor  = MTLClearColorMake(1, 1, 1, 1);
desc.colorAttachments[0].storeAction = MTLStoreActionStore;

[Try]

new syntax idea:

1. discard FrameBuffer & RenderPass classes

2. {
   auto enc = cmdBuf.startEncoding(device);
   enc.setFramebuffer({{color,Color(0,0,0,0),Tempest::Preserve}, {normal,Tempest::Discard,Tempest::Preserve}});
   enc.setUniforms(op,ubo,&uboCpu,sizeof(uboCpu));
   enc.draw(Resources::fsq());
   }

[Try]

Add readable depth texture

Moved: #27

Reconsider design cross-queue/cpu synchronization

De-scoped, single queue case is problematic enough.

VK_EXT_inline_uniform_block

Moved: #32