Lightshaderclass.cpp

////////////////////////////////////////////////////////////////////////////////
// Filename: lightshaderclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "lightshaderclass.h"


LightShaderClass::LightShaderClass()
{
	m_vertexShader = 0;
	m_pixelShader = 0;
	m_layout = 0;
	m_sampleState = 0;
	m_matrixBuffer = 0;
	//Initialize the new camera constant buffer to null in the class constructor.

	m_cameraBuffer = 0;
	m_lightBuffer = 0;
}


LightShaderClass::LightShaderClass(const LightShaderClass& other)
{
}


LightShaderClass::~LightShaderClass()
{
}


bool LightShaderClass::Initialize(ID3D11Device* device, HWND hwnd)
{
	bool result;


	// Initialize the vertex and pixel shaders.
	result = InitializeShader(device, hwnd, L"data\\shaders\\light.vs", L"data\\shaders\\light.ps");
	if (!result)
	{
		return false;
	}

	return true;
}


void LightShaderClass::Shutdown()
{
	// Shutdown the vertex and pixel shaders as well as the related objects.
	ShutdownShader();

	return;
}


//The Render function now takes in cameraPosition, specularColor, and specularPower values and sends them into the SetShaderParameters function to make them active in the light shader before rendering occurs.

bool LightShaderClass::Render(ID3D11DeviceContext* deviceContext, int indexCount, XMMATRIX worldMatrix, XMMATRIX viewMatrix,
	XMMATRIX projectionMatrix, ID3D11ShaderResourceView* texture, XMFLOAT3 lightDirection, XMFLOAT4 ambientColor,
	XMFLOAT4 diffuseColor, XMFLOAT3 cameraPosition, XMFLOAT4 specularColor, float specularPower)
{
	bool result;


	// Set the shader parameters that it will use for rendering.
	result = SetShaderParameters(deviceContext, worldMatrix, viewMatrix, projectionMatrix, texture, lightDirection, ambientColor, diffuseColor,
		cameraPosition, specularColor, specularPower);
	if (!result)
	{
		return false;
	}

	// Now render the prepared buffers with the shader.
	RenderShader(deviceContext, indexCount);

	return true;
}


bool LightShaderClass::InitializeShader(ID3D11Device* device, HWND hwnd, WCHAR* vsFilename, WCHAR* psFilename)
{
	HRESULT result;
	ID3D10Blob* errorMessage;
	ID3D10Blob* vertexShaderBuffer;
	ID3D10Blob* pixelShaderBuffer;
	D3D11_INPUT_ELEMENT_DESC polygonLayout[3];
	unsigned int numElements;
	D3D11_SAMPLER_DESC samplerDesc;
	D3D11_BUFFER_DESC matrixBufferDesc;
	D3D11_BUFFER_DESC cameraBufferDesc;
	D3D11_BUFFER_DESC lightBufferDesc;


	// Initialize the pointers this function will use to null.
	errorMessage = 0;
	vertexShaderBuffer = 0;
	pixelShaderBuffer = 0;

	// Compile the vertex shader code.
	result = D3DCompileFromFile(vsFilename, NULL, NULL, "LightVertexShader", "vs_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0,
		&vertexShaderBuffer, &errorMessage);
	if (FAILED(result))
	{
		// If the shader failed to compile it should have writen something to the error message.
		if (errorMessage)
		{
			OutputShaderErrorMessage(errorMessage, hwnd, vsFilename);
		}
		// If there was nothing in the error message then it simply could not find the shader file itself.
		else
		{
			MessageBox(hwnd, vsFilename, L"Missing Shader File", MB_OK);
		}

		return false;
	}

	// Compile the pixel shader code.
	result = D3DCompileFromFile(psFilename, NULL, NULL, "LightPixelShader", "ps_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0,
		&pixelShaderBuffer, &errorMessage);
	if (FAILED(result))
	{
		// If the shader failed to compile it should have writen something to the error message.
		if (errorMessage)
		{
			OutputShaderErrorMessage(errorMessage, hwnd, psFilename);
		}
		// If there was nothing in the error message then it simply could not find the file itself.
		else
		{
			MessageBox(hwnd, psFilename, L"Missing Shader File", MB_OK);
		}

		return false;
	}

	// Create the vertex shader from the buffer.
	result = device->CreateVertexShader(vertexShaderBuffer->GetBufferPointer(), vertexShaderBuffer->GetBufferSize(), NULL, &m_vertexShader);
	if (FAILED(result))
	{
		return false;
	}

	// Create the pixel shader from the buffer.
	result = device->CreatePixelShader(pixelShaderBuffer->GetBufferPointer(), pixelShaderBuffer->GetBufferSize(), NULL, &m_pixelShader);
	if (FAILED(result))
	{
		return false;
	}

	// Create the vertex input layout description.
	// This setup needs to match the VertexType stucture in the ModelClass and in the shader.
	polygonLayout[0].SemanticName = "POSITION";
	polygonLayout[0].SemanticIndex = 0;
	polygonLayout[0].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[0].InputSlot = 0;
	polygonLayout[0].AlignedByteOffset = 0;
	polygonLayout[0].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
	polygonLayout[0].InstanceDataStepRate = 0;

	polygonLayout[1].SemanticName = "TEXCOORD";
	polygonLayout[1].SemanticIndex = 0;
	polygonLayout[1].Format = DXGI_FORMAT_R32G32_FLOAT;
	polygonLayout[1].InputSlot = 0;
	polygonLayout[1].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
	polygonLayout[1].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
	polygonLayout[1].InstanceDataStepRate = 0;

	polygonLayout[2].SemanticName = "NORMAL";
	polygonLayout[2].SemanticIndex = 0;
	polygonLayout[2].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[2].InputSlot = 0;
	polygonLayout[2].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
	polygonLayout[2].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
	polygonLayout[2].InstanceDataStepRate = 0;

	// Get a count of the elements in the layout.
	numElements = sizeof(polygonLayout) / sizeof(polygonLayout[0]);

	// Create the vertex input layout.
	result = device->CreateInputLayout(polygonLayout, numElements, vertexShaderBuffer->GetBufferPointer(), vertexShaderBuffer->GetBufferSize(),
		&m_layout);
	if (FAILED(result))
	{
		return false;
	}

	// Release the vertex shader buffer and pixel shader buffer since they are no longer needed.
	vertexShaderBuffer->Release();
	vertexShaderBuffer = 0;

	pixelShaderBuffer->Release();
	pixelShaderBuffer = 0;

	// Create a texture sampler state description.
	samplerDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
	samplerDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.MipLODBias = 0.0f;
	samplerDesc.MaxAnisotropy = 1;
	samplerDesc.ComparisonFunc = D3D11_COMPARISON_ALWAYS;
	samplerDesc.BorderColor[0] = 0;
	samplerDesc.BorderColor[1] = 0;
	samplerDesc.BorderColor[2] = 0;
	samplerDesc.BorderColor[3] = 0;
	samplerDesc.MinLOD = 0;
	samplerDesc.MaxLOD = D3D11_FLOAT32_MAX;

	// Create the texture sampler state.
	result = device->CreateSamplerState(&samplerDesc, &m_sampleState);
	if (FAILED(result))
	{
		return false;
	}

	// Setup the description of the dynamic matrix constant buffer that is in the vertex shader.
	matrixBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
	matrixBufferDesc.ByteWidth = sizeof(MatrixBufferType);
	matrixBufferDesc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
	matrixBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
	matrixBufferDesc.MiscFlags = 0;
	matrixBufferDesc.StructureByteStride = 0;

	// Create the constant buffer pointer so we can access the vertex shader constant buffer from within this class.
	result = device->CreateBuffer(&matrixBufferDesc, NULL, &m_matrixBuffer);
	if (FAILED(result))
	{
		return false;
	}
	//We setup the description of the new camera buffer and then create a buffer using that description.This will allow us to interface with and set the camera position in the vertex shader.

		// Setup the description of the camera dynamic constant buffer that is in the vertex shader.
	cameraBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
	cameraBufferDesc.ByteWidth = sizeof(CameraBufferType);
	cameraBufferDesc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
	cameraBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
	cameraBufferDesc.MiscFlags = 0;
	cameraBufferDesc.StructureByteStride = 0;

	// Create the camera constant buffer pointer so we can access the vertex shader constant buffer from within this class.
	result = device->CreateBuffer(&cameraBufferDesc, NULL, &m_cameraBuffer);
	if (FAILED(result))
	{
		return false;
	}

	// Setup the description of the light dynamic constant buffer that is in the pixel shader.
	// Note that ByteWidth always needs to be a multiple of 16 if using D3D11_BIND_CONSTANT_BUFFER or CreateBuffer will fail.
	lightBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
	lightBufferDesc.ByteWidth = sizeof(LightBufferType);
	lightBufferDesc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
	lightBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
	lightBufferDesc.MiscFlags = 0;
	lightBufferDesc.StructureByteStride = 0;

	// Create the constant buffer pointer so we can access the vertex shader constant buffer from within this class.
	result = device->CreateBuffer(&lightBufferDesc, NULL, &m_lightBuffer);
	if (FAILED(result))
	{
		return false;
	}

	return true;
}


void LightShaderClass::ShutdownShader()
{
	// Release the light constant buffer.
	if (m_lightBuffer)
	{
		m_lightBuffer->Release();
		m_lightBuffer = 0;
	}
	//Release the new camera constant buffer in the ShutdownShader function.

	// Release the camera constant buffer.
	if (m_cameraBuffer)
	{
		m_cameraBuffer->Release();
		m_cameraBuffer = 0;
	}

	// Release the matrix constant buffer.
	if (m_matrixBuffer)
	{
		m_matrixBuffer->Release();
		m_matrixBuffer = 0;
	}

	// Release the sampler state.
	if (m_sampleState)
	{
		m_sampleState->Release();
		m_sampleState = 0;
	}

	// Release the layout.
	if (m_layout)
	{
		m_layout->Release();
		m_layout = 0;
	}

	// Release the pixel shader.
	if (m_pixelShader)
	{
		m_pixelShader->Release();
		m_pixelShader = 0;
	}

	// Release the vertex shader.
	if (m_vertexShader)
	{
		m_vertexShader->Release();
		m_vertexShader = 0;
	}

	return;
}


void LightShaderClass::OutputShaderErrorMessage(ID3D10Blob* errorMessage, HWND hwnd, WCHAR* shaderFilename)
{
	char* compileErrors;
	unsigned long bufferSize, i;
	ofstream fout;


	// Get a pointer to the error message text buffer.
	compileErrors = (char*)(errorMessage->GetBufferPointer());

	// Get the length of the message.
	bufferSize = errorMessage->GetBufferSize();

	// Open a file to write the error message to.
	fout.open("shader-error.txt");

	// Write out the error message.
	for (i = 0; i<bufferSize; i++)
	{
		fout << compileErrors[i];
	}

	// Close the file.
	fout.close();

	// Release the error message.
	errorMessage->Release();
	errorMessage = 0;

	// Pop a message up on the screen to notify the user to check the text file for compile errors.
	MessageBox(hwnd, L"Error compiling shader.  Check shader-error.txt for message.", shaderFilename, MB_OK);

	return;
}

//The SetShaderParameters function has been modified to take as input cameraPosition, specularColor, and specularPower.

bool LightShaderClass::SetShaderParameters(ID3D11DeviceContext* deviceContext, XMMATRIX worldMatrix, XMMATRIX viewMatrix,
	XMMATRIX projectionMatrix, ID3D11ShaderResourceView* texture, XMFLOAT3 lightDirection,
	XMFLOAT4 ambientColor, XMFLOAT4 diffuseColor, XMFLOAT3 cameraPosition, XMFLOAT4 specularColor,
	float specularPower)
{
	HRESULT result;
	D3D11_MAPPED_SUBRESOURCE mappedResource;
	unsigned int bufferNumber;
	MatrixBufferType* dataPtr;
	LightBufferType* dataPtr2;
	CameraBufferType* dataPtr3;


	// Transpose the matrices to prepare them for the shader.
	worldMatrix = XMMatrixTranspose(worldMatrix);
	viewMatrix = XMMatrixTranspose(viewMatrix);
	projectionMatrix = XMMatrixTranspose(projectionMatrix);

	// Lock the constant buffer so it can be written to.
	result = deviceContext->Map(m_matrixBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
	if (FAILED(result))
	{
		return false;
	}

	// Get a pointer to the data in the constant buffer.
	dataPtr = (MatrixBufferType*)mappedResource.pData;

	// Copy the matrices into the constant buffer.
	dataPtr->world = worldMatrix;
	dataPtr->view = viewMatrix;
	dataPtr->projection = projectionMatrix;

	// Unlock the constant buffer.
	deviceContext->Unmap(m_matrixBuffer, 0);

	// Set the position of the constant buffer in the vertex shader.
	bufferNumber = 0;

	// Now set the constant buffer in the vertex shader with the updated values.
	deviceContext->VSSetConstantBuffers(bufferNumber, 1, &m_matrixBuffer);

	//Here we lock the camera buffer and set the camera position value in it.

	// Lock the camera constant buffer so it can be written to.
	result = deviceContext->Map(m_cameraBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
	if (FAILED(result))
	{
		return false;
	}

	// Get a pointer to the data in the constant buffer.
	dataPtr3 = (CameraBufferType*)mappedResource.pData;

	// Copy the camera position into the constant buffer.
	dataPtr3->cameraPosition = cameraPosition;
	dataPtr3->padding = 0.0f;

	// Unlock the camera constant buffer.
	deviceContext->Unmap(m_cameraBuffer, 0);
	
	//Note that we set the bufferNumber to 1 instead of 0 before setting the constant buffer.This is because it is the second buffer in the vertex shader(the first being the matrix buffer).

	// Set the position of the camera constant buffer in the vertex shader.
	bufferNumber = 1;

	// Now set the camera constant buffer in the vertex shader with the updated values.
	deviceContext->VSSetConstantBuffers(bufferNumber, 1, &m_cameraBuffer);

	// Set shader texture resource in the pixel shader.
	deviceContext->PSSetShaderResources(0, 1, &texture);

	// Lock the light constant buffer so it can be written to.
	result = deviceContext->Map(m_lightBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource);
	if (FAILED(result))
	{
		return false;
	}

	// Get a pointer to the data in the light constant buffer.
	dataPtr2 = (LightBufferType*)mappedResource.pData;
	
	//The light constant buffer now sets the specular color and specular power so that the pixel shader can perform specular lighting calculations.

	// Copy the lighting variables into the light constant buffer.
	dataPtr2->ambientColor = ambientColor;
	dataPtr2->diffuseColor = diffuseColor;
	dataPtr2->lightDirection = lightDirection;
	dataPtr2->specularColor = specularColor;
	dataPtr2->specularPower = specularPower;

	// Unlock the light constant buffer.
	deviceContext->Unmap(m_lightBuffer, 0);

	// Set the position of the light constant buffer in the pixel shader.
	bufferNumber = 0;

	// Finally set the light constant buffer in the pixel shader with the updated values.
	deviceContext->PSSetConstantBuffers(bufferNumber, 1, &m_lightBuffer);

	return true;
}


void LightShaderClass::RenderShader(ID3D11DeviceContext* deviceContext, int indexCount)
{
	// Set the vertex input layout.
	deviceContext->IASetInputLayout(m_layout);

	// Set the vertex and pixel shaders that will be used to render this triangle.
	deviceContext->VSSetShader(m_vertexShader, NULL, 0);
	deviceContext->PSSetShader(m_pixelShader, NULL, 0);

	// Set the sampler state in the pixel shader.
	deviceContext->PSSetSamplers(0, 1, &m_sampleState);

	// Render the triangle.
	deviceContext->DrawIndexed(indexCount, 0, 0);

	return;
}