Hello,

I am trying to texture a simple quad. My 'engine' can currently create a quad and I would like to expand it to be able to load textures.

My current attempt is as follows:

	Vertex vtx[] =
	{
		Vertex(-1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f),
		Vertex(1.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 1.0f),
		Vertex(-1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f),
		Vertex(1.0f, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f),
	};

	createVertexBuffer(ARRAYSIZE(vtx), vtx, &vertexBuffer);
	createShaders();

	D3DX11CreateShaderResourceViewFromFile(d3d11Device, "textures\\t1.bmp", NULL, NULL, &texture, NULL);

	d3d11DevCon->PSSetShaderResources(0, 1, &texture);
	d3d11DevCon->Draw(4, 0);

where texture is of type ID3D11ShaderResourceView

The problem is I am reusing the same.fx file which is as follows:

cbuffer cbPerObject
{
	float4x4 WVP;
};

struct VS_OUTPUT
{
	float4 Pos : SV_POSITION;
	float4 Color : COLOR;
};

VS_OUTPUT VS(float4 inPos : POSITION, float4 inColor : COLOR)
{
    VS_OUTPUT output;
    output.Pos = mul(inPos, WVP);
    output.Color = inColor;

    return output;
}

float4 PS(VS_OUTPUT input) : SV_TARGET
{
    return input.Color;
}

I am stuck understanding how to edit the .fx file to allow for textures. And if I have correctly laid out code that will draw my textured quad.

Thank for your yout time

1. Create a correct vertex buffer, no need for color declaration

struct SVertex
{
    D3DXVECTOR2 PosS;   // Screen space position
    D3DXVECTOR2 TexC;   // Texture coordinates
};

static const SVertex gFullScreenQuadVertices[] = 
{
    {D3DXVECTOR2(-1.0f, -1.0f), D3DXVECTOR2(0.0f,  1.0f)},
    {D3DXVECTOR2(-1.0f,  1.0f), D3DXVECTOR2(0.0f,  0.0f)},
    {D3DXVECTOR2( 1.0f, -1.0f), D3DXVECTOR2(1.0f,  1.0f)},
    {D3DXVECTOR2( 1.0f,  1.0f), D3DXVECTOR2(1.0f,  0.0f)},
};

2. Input layout is

    D3D11_INPUT_ELEMENT_DESC layoutDesc[] = 
    {
        {"POSITION", 0, DXGI_FORMAT_R32G32_FLOAT, 0, offsetof(SVertex, PosS), D3D11_INPUT_PER_VERTEX_DATA, 0},                
        {"TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT,0, offsetof(SVertex, TexC), D3D11_INPUT_PER_VERTEX_DATA, 0},                
    };

3. VS should be pass-through:

void VS(float4 PosL : POSITION, inout float2 TexC : TEXCOORD, out float4 svPos : SV_POSITION)
{
    svPos = PosL;
}

Note the TexC is declared as inout, so the compiler will create a code to pass it to the PS.

4. PS needs to do texture sampling:

SamplerState gSampler : register(s0);
Texture2D gSRV : register(t0);

float4 PS(float2 TexC : TEXCOORD) : SV_TARGET
{
    float3 c = gSRV.Sample(gSampler, TexC).rgb;
    return float4(c, 1);
}

Note that in order to do this you need to create a sample state. Check CreateSamplerState() for documentation. Basic tri-linear sampler is

// Create point sampler state
    D3D11_SAMPLER_DESC desc;
    desc.AddressU = desc.AddressV = desc.AddressW = D3D11_TEXTURE_ADDRESS_WARP;
    desc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
    desc.MinLOD = 0;
    desc.MaxLOD = D3D11_FLOAT32_MAX;
    desc.MipLODBias = 0;
    desc.MaxAnisotropy = 0;
    V(pDevice->CreateSamplerState(&desc, &LinearSampler));

Then set it before the draw call using PSSetSamplers().

Thank you very much for taking the time to assist me. I have not yet had time to implement this but once I do I will let you know how it went.

I finally got around to making this work in its own separate program so thanks. I have a question though:

Right now my 'game' consists of primitive shapes that just have a color, and textured shapes which are the walls. When compiling the game objects and shaders, it is better to use separate .fx files for each different game asset, or just add everything you need in one big shader file.

I hope the question makes sense because I am still quite confused about vertex and pixel shaders.

Thanks again