An Introduction to Texture Mapping in Direct3D

An Introduction to Texture Mapping in Direct3D
with Examples in C++

Prof. David Bernstein
James Madison University

Computer Science Department

bernstdh@jmu.edu

Parts of the Process

Define a custom vertex format
Create a texture
Select a texture
Specify parameters
Enabling texture mapping

Defining a Custom Vertex Format

The Custom Vertex struct:
- Add two float values for the texture coordinates \(u\) and \(v\)
Set the Flexible Vertex Format (FVF):
- Use the bitflag D3DFVF_TEX1

Defining a Custom Vertex Format (cont.)

An Example

directx9examples/textures/cube/cube.cpp

(Fragment: vertices)

// Specify the struct for a vertex
struct CUSTOMVERTEX
{
    float x, y, z;
        float u, v;     // Texture coordinates
};

// Specify the flexible vertex format (FVF) for the struct above
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ | D3DFVF_TEX1)


// Color Definitions
DWORD colorBlue   = 0xFF0000FF;
DWORD colorGold   = 0xFFC2A14D; // JMU Gold
DWORD colorGray   = 0xFFAAAAAA;
DWORD colorGreen  = 0xFF00FF00;
DWORD colorPurple = 0xFF450084; // JMU Purple
DWORD colorRed    = 0xFFFF0000;
DWORD colorYellow = 0xFFFFFF00;

// Create the vertex elements
CUSTOMVERTEX vertices[] =
{
        {-1.0f, 1.0f,-1.0f,  0.0f,  0.0f}, // Front
        { 1.0f, 1.0f,-1.0f,  1.0f,  0.0f},
        {-1.0f,-1.0f,-1.0f,  0.0f,  1.0f},
        { 1.0f,-1.0f,-1.0f,  1.0f,  1.0f},
        
        {-1.0f, 1.0f, 1.0f,  1.0f,  0.0f}, // Back
        {-1.0f,-1.0f, 1.0f,  1.0f,  1.0f},
        { 1.0f, 1.0f, 1.0f,  0.0f,  0.0f},
        { 1.0f,-1.0f, 1.0f,  0.0f,  1.0f},
        
        {-1.0f, 1.0f, 1.0f,  0.0f,  0.0f}, // Top
        { 1.0f, 1.0f, 1.0f,  1.0f,  0.0f},
        {-1.0f, 1.0f,-1.0f,  0.0f,  1.0f},
        { 1.0f, 1.0f,-1.0f,  1.0f,  1.0f},
        
        {-1.0f,-1.0f, 1.0f,  0.0f,  0.0f}, // Bottom
        {-1.0f,-1.0f,-1.0f,  1.0f,  0.0f},
        { 1.0f,-1.0f, 1.0f,  0.0f,  1.0f},
        { 1.0f,-1.0f,-1.0f,  1.0f,  1.0f},

        { 1.0f, 1.0f,-1.0f,  0.0f,  0.0f}, // Right
        { 1.0f, 1.0f, 1.0f,  1.0f,  0.0f},
        { 1.0f,-1.0f,-1.0f,  0.0f,  1.0f},
        { 1.0f,-1.0f, 1.0f,  1.0f,  1.0f},
        
        {-1.0f, 1.0f,-1.0f,  1.0f,  0.0f}, // Left
        {-1.0f,-1.0f,-1.0f,  1.0f,  1.0f},
        {-1.0f, 1.0f, 1.0f,  0.0f,  0.0f},
        {-1.0f,-1.0f, 1.0f,  0.0f,  1.0f}
};

Creating a Texture

From a file:
- HRESULT D3DXCreateTextureFromFile(LPDIRECT3DDEVICE9 device, LPCTSTR sourceFile, LPDIRECT3DTEXTURE9* texture)
Creates:
- An object that implements the IDirect3DTexture9 interface

Creating a Texture (cont.)

An Example

directx9examples/textures/cube/cube.cpp

(Fragment: create)

// Allocate memory for the textures
LPDIRECT3DTEXTURE9      texture[6];

        ZeroMemory(texture, 6*sizeof(LPDIRECT3DTEXTURE9));

        // Create one texture for each face
    D3DXCreateTextureFromFile(d3dDevice, L"brick.bmp",        &texture[0]);
    D3DXCreateTextureFromFile(d3dDevice, L"brownpaper.bmp",   &texture[1]);
    D3DXCreateTextureFromFile(d3dDevice, L"flagstone.bmp",    &texture[2]);
    D3DXCreateTextureFromFile(d3dDevice, L"frostedglass.bmp", &texture[3]);
    D3DXCreateTextureFromFile(d3dDevice, L"lake.bmp",         &texture[4]);
    D3DXCreateTextureFromFile(d3dDevice, L"oak.bmp",          &texture[5]);

Selecting a Texture

The Method:
- HRESULT IDirect3DDevice9::SetTexture(DWORD sampler, IDirect3DBaseTexture9* texture)
Remember:
- This changes the state of the renderer so it may need to be called once or multiple times (e.g., once for each primitive) depending on the application

Selecting a Texture (cont.)

An Example

directx9examples/textures/cube/cube.cpp

(Fragment: select)

                // Draw the various shapes (two triangles for each face)
                d3dDevice->SetTexture(0, texture[0]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP,  0, 2);

                d3dDevice->SetTexture(0, texture[1]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP,  4, 2);

                d3dDevice->SetTexture(0, texture[2]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP,  8, 2);

                d3dDevice->SetTexture(0, texture[3]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 12, 2);

                d3dDevice->SetTexture(0, texture[4]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 16, 2);

                d3dDevice->SetTexture(0, texture[5]);
                d3dDevice->DrawPrimitive(D3DPT_TRIANGLESTRIP, 20, 2);

Specifiying Parameters

The Method:
- HRESULT IDirect3DDevice9::SetTextureStageState(DWORD stage, D3DTEXTURESTAGESTATETYPE name, DWORD value)
The name:
- D3DTSS_COLOROP,D3DTSS_COLORARG1, D3DTSS_COLORARG2,D3DTSS_ALPHAOP, D3DTSS_ALPHAARG1,D3DTSS_ALPHAARG2, D3DTSS_BUMPENVMAT00,D3DTSS_BUMPENVMAT01, D3DTSS_BUMPENVMAT10,D3DTSS_BUMPENVMAT11, D3DTSS_TEXCOORDINDEX,D3DTSS_BUMPENVLSCALE, D3DTSS_BUMPENVLOFFSET, D3DTSS_TEXTURETRANSFORMFLAGS, D3DTSS_COLORARG0,D3DTSS_ALPHAARG0, D3DTSS_RESULTARG,D3DTSS_CONSTANT, D3DTSS_FORCE_DWORD

Specifiying Parameters (cont.)

An Example

directx9examples/textures/cube/cube.cpp

(Fragment: setup)

        // Set texture-mapping properties
        d3dDevice->SetSamplerState(0, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
    d3dDevice->SetSamplerState(0, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);