Sky.cpp

#include "Sky.h"
#include "Helpers.h"

#pragma comment(lib, "d3dcompiler.lib")
#include <d3dcompiler.h>

#include <WICTextureLoader.h>

#include <cstring>

using namespace DirectX;

// --------------------------------------------------------
// Loads six individual textures (the six faces of a cube map), then
// creates a blank cube map and copies each of the six textures to
// another face.  Afterwards, creates a shader resource view for
// the cube map and cleans up all of the temporary resources.
// --------------------------------------------------------
Microsoft::WRL::ComPtr<ID3D11ShaderResourceView> Sky::CreateCubemap(
	const wchar_t* right,
	const wchar_t* left,
	const wchar_t* up,
	const wchar_t* down,
	const wchar_t* front,
	const wchar_t* back) {
	// Load the 6 textures into an array.
	// - We need references to the TEXTURES, not SHADER RESOURCE VIEWS!
	// - Explicitly NOT generating mipmaps, as we don't need them for the sky!
	// - Order matters here!  +X, -X, +Y, -Y, +Z, -Z
	Microsoft::WRL::ComPtr<ID3D11Texture2D> textures[6] = {};
	CreateWICTextureFromFile(device.Get(), right, (ID3D11Resource**)textures[0].GetAddressOf(), 0);
	CreateWICTextureFromFile(device.Get(), left, (ID3D11Resource**)textures[1].GetAddressOf(), 0);
	CreateWICTextureFromFile(device.Get(), up, (ID3D11Resource**)textures[2].GetAddressOf(), 0);
	CreateWICTextureFromFile(device.Get(), down, (ID3D11Resource**)textures[3].GetAddressOf(), 0);
	CreateWICTextureFromFile(device.Get(), front, (ID3D11Resource**)textures[4].GetAddressOf(), 0);
	CreateWICTextureFromFile(device.Get(), back, (ID3D11Resource**)textures[5].GetAddressOf(), 0);

	// We'll assume all of the textures are the same color format and resolution,
	// so get the description of the first texture
	D3D11_TEXTURE2D_DESC faceDesc = {};
	textures[0]->GetDesc(&faceDesc);

	// Describe the resource for the cube map, which is simply 
	// a "texture 2d array" with the TEXTURECUBE flag set.  
	// This is a special GPU resource format, NOT just a 
	// C++ array of textures!!!
	D3D11_TEXTURE2D_DESC cubeDesc = {};
	cubeDesc.ArraySize = 6;            // Cube map!
	cubeDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE; // We'll be using as a texture in a shader
	cubeDesc.CPUAccessFlags = 0;       // No read back
	cubeDesc.Format = faceDesc.Format; // Match the loaded texture's color format
	cubeDesc.Width = faceDesc.Width;   // Match the size
	cubeDesc.Height = faceDesc.Height; // Match the size
	cubeDesc.MipLevels = 1;            // Only need 1
	cubeDesc.MiscFlags = D3D11_RESOURCE_MISC_TEXTURECUBE; // This should be treated as a CUBE, not 6 separate textures
	cubeDesc.Usage = D3D11_USAGE_DEFAULT; // Standard usage
	cubeDesc.SampleDesc.Count = 1;
	cubeDesc.SampleDesc.Quality = 0;

	// Create the final texture resource to hold the cube map
	Microsoft::WRL::ComPtr<ID3D11Texture2D> cubeMapTexture;
	device->CreateTexture2D(&cubeDesc, 0, cubeMapTexture.GetAddressOf());

	// Loop through the individual face textures and copy them,
	// one at a time, to the cube map texure
	for (int i = 0; i < 6; i++) {
		// Calculate the subresource position to copy into
		unsigned int subresource = D3D11CalcSubresource(
			0,  // Which mip (zero, since there's only one)
			i,  // Which array element?
			1); // How many mip levels are in the texture?

		// Copy from one resource (texture) to another
		context->CopySubresourceRegion(
			cubeMapTexture.Get(),  // Destination resource
			subresource,           // Dest subresource index (one of the array elements)
			0, 0, 0,               // XYZ location of copy
			textures[i].Get(),     // Source resource
			0,                     // Source subresource index (we're assuming there's only one)
			0);                    // Source subresource "box" of data to copy (zero means the whole thing)
	}

	// At this point, all of the faces have been copied into the 
	// cube map texture, so we can describe a shader resource view for it
	D3D11_SHADER_RESOURCE_VIEW_DESC srvDesc = {};
	srvDesc.Format = cubeDesc.Format;         // Same format as texture
	srvDesc.ViewDimension = D3D11_SRV_DIMENSION_TEXTURECUBE; // Treat this as a cube!
	srvDesc.TextureCube.MipLevels = 1;        // Only need access to 1 mip
	srvDesc.TextureCube.MostDetailedMip = 0;  // Index of the first mip we want to see

	// Make the SRV
	Microsoft::WRL::ComPtr<ID3D11ShaderResourceView> cubeSRV;
	device->CreateShaderResourceView(cubeMapTexture.Get(), &srvDesc, cubeSRV.GetAddressOf());

	// Send back the SRV, which is what we need for our shaders
	return cubeSRV;
}

Sky::Sky(
    std::shared_ptr<Mesh> mesh,
    Microsoft::WRL::ComPtr<ID3D11SamplerState> samplerState,
    Microsoft::WRL::ComPtr<ID3D11Device> device,
    Microsoft::WRL::ComPtr<ID3D11DeviceContext>	context,
    std::shared_ptr<SimpleVertexShader> vs,
    std::shared_ptr<SimplePixelShader> ps,
    std::vector<std::wstring> filesToLoad
) : 
    skyMesh(mesh),
    samplerOptions(samplerState),
    device(device),
    context(context),
    vertexShader(vs),
    pixelShader(ps) {

    //Create the Cube Map SRV
    textureSRV = CreateCubemap(
        filesToLoad[0].c_str(),
        filesToLoad[1].c_str(),
        filesToLoad[2].c_str(),
        filesToLoad[3].c_str(),
        filesToLoad[4].c_str(),
        filesToLoad[5].c_str()
    );

    //Create the Rasterizer State
    D3D11_RASTERIZER_DESC rasterizerDesc = {};
    rasterizerDesc.FillMode = D3D11_FILL_SOLID;
    rasterizerDesc.CullMode = D3D11_CULL_FRONT;

    device->CreateRasterizerState(&rasterizerDesc, rasterizerState.GetAddressOf());

    //Create the Depth-Stencil State
    D3D11_DEPTH_STENCIL_DESC depthStencilDesc = {};
    depthStencilDesc.DepthEnable = true;
	//depthStencilDesc.StencilWriteMask = D3D10_DEPTH_WRITE_MASK_ALL;
    depthStencilDesc.DepthFunc = D3D11_COMPARISON_LESS_EQUAL;

    device->CreateDepthStencilState(&depthStencilDesc, depthStencilState.GetAddressOf());

}

Sky::~Sky() {
}

void Sky::Draw(std::shared_ptr<Camera> camera) {
    //Set the render states
    context->RSSetState(rasterizerState.Get());
    context->OMSetDepthStencilState(depthStencilState.Get(), 0);

    //Prepare sky-specific shaders for drawing
    vertexShader->SetShader();
    pixelShader->SetShader();

    vertexShader->SetMatrix4x4("view", camera->GetView());
    vertexShader->SetMatrix4x4("projection", camera->GetProjection());

    pixelShader->SetShaderResourceView("CubeMap", textureSRV);
    pixelShader->SetSamplerState("SkySampler", samplerOptions);

    vertexShader->CopyAllBufferData();
    pixelShader->CopyAllBufferData();

    //Draw the mesh
    skyMesh->Draw();

    //Reset render states
    context->RSSetState(0);
	context->OMSetDepthStencilState(0, 0);
}