Another week of GRasterSurface has come and gone, but much more progress has been made toward finishing it. We've finally got it passing all of the tests* and drawing images to the screen. The only thing that should be left to do is modify SmartUpdateSurface() so that it can utilize hardware acceleration, and then we don't have to worry about unnecessary thread locking and unlocking.
As I mentioned last week, I decided to just implement GRasterSurface using DirectX11 to avoid using weird external libraries, and it'll be a much more efficient implementation. I started by doing some research into how to set up the DX11 surface along with everything that goes along with it, like the shaders, buffers, descriptions, and the texture itself. The two main resources that proved to be helpful in getting all of this set up were the API examples from Full Sail's 3D Content Creation class and a Stack Overflow post.
The class examples have an example of a renderer that utilizes texturing, and this provided the main foundation for setting up everything. I had to modify the vertex shader a bit since we don't have to worry about matrix math and putting things in world space, but the pixel shader was able to work right out of the box.
Along with the standard setup process, it also showed the process for sending a Texture2D to the GPU using a ShaderResourceView and SamplerState. This part was definitely much more of a mystery to me beforehand since I haven't done any sort of texturing in graphics before, let alone in DirectX11, which I have virtually no experience with. But the main problem with this example is how it is actually making its Texture2D. The example is creating textures from DDS files which requires a completely different method of creating the texture from what you would do to create a texture from an array of pixels.
So this is where the second main resource comes into play. Since I couldn't use the DDS method that is used in the example, I did some research into how to create a Texture2D from an array of pixels, and I stumbled across the Stack Overflow post linked below. This showed how to set up the texture description, create a Texture2D using that, and create a ShaderResourceView using the texture. However, creating a Texture2D every time we have a new image to display can be very expensive, so we're only re-creating it when the window is resized. So how do we get new images to the Texture2D?
https://stackoverflow.com/questions/41627317/directx-11-how-to-create-a-very-simple-2d-texture
This is where my third, secret resource comes from; people! Lari Norri was able to help me out with being able to Map and Unmap the texture's data so that we can update the texture in a very low-cost way. This was able to get a lot of the universal functions finished, like the lock/unlock functions and UpdateSurface and UpdateSurfaceSubset. I was also able to get some help from some other people at Full Sail with the occasional DirectX11 thing.
So now GRasterSurface is just about finished, but as you may remember from the beginning of this post, SmartUpdateSurface() still needs to be done and that's also kind of the asterisk to all the unit tests passed. Since SmartUpdateSurface() isn't doing anything at the moment, GRasterSurface can't really pass the tests that require that function, so they're commented out at the moment. But I'm hoping to be able to get SmartUpdateSurface done by early next week so that I can stay on schedule with what I've got planned for this month. But only time will tell.
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