DirectX基础学习系列4 颜色和光照
4.1颜色表示
RGB颜色：D3DCOLOR 可以用宏D3DCOLOR_ARGB(a,r,g,b) D3DCOLOR_XRGB(255,r,g,b)
另外一种浮点表示：D3DCOLORVALUE，浮点类型，最小为0 最大为1
4.2顶点颜色
struct ColorVetex
{
float x, y,z;
D3DCOLOR color;
static const DWORD FVF;
}
const DWORD ColorVetex::FVF = D3DFVF_XYZ | D3DFVF_DIFFUSE ;
4.3着色
两种着色方式：shading mode
1flat shading 平面着色：每个图元的像素都被赋予该图元的第一个顶点的颜色
2gourand shading ：各像素的颜色由着色的三个顶点颜色插值决定、
设置着色模式：Device->SetRenderState(D3DRS_SHADEMODE, D3DSHADE_FLAT);
5 光照
5.1光照的组成
1环境光
2漫射光：特定方向，达到表面后均匀反射
3镜面光 ：特定方向，达到表面后严格向另外一个方向反射，形成在一定范围内可看的高亮区域，计算量很大
可以控制开关：Device->SetRenderState(D3DRS_SPECULARENABLE, TRUE);
5.2材质
材质允许定义对各种颜色光的反射比
typedef struct D3DMATERIAL9 {
D3DCOLORVALUE Diffuse;
D3DCOLORVALUE Ambient;
D3DCOLORVALUE Specular;
D3DCOLORVALUE Emissive;
float Power;
} D3DMATERIAL9, *LPD3DMATERIAL9;
设置材质属性：HRESULT SetMaterial( CONST D3DMATERIAL9 * pMaterial );
5.3顶点法线
struct ColorVetex
{
float x, y,z;
float _nx,_ny,_nz ;
static const DWORD FVF;
}
const DWORD ColorVetex::FVF = D3DFVF_XYZ | D3DFVF_NORMAL;
注意顶点向量的规范化：Device->SetRenderState(D3DRS_NORMALIZEENABLE, TRUE);
5.4 光源
DX支持的三种光源：点光源，方向光，聚光灯
typedef struct D3DLIGHT9 {
D3DLIGHTTYPE Type; //D3DLIGHT_POINT D3DLIGHT_SPOT D3DLIGHT_DIRECTIONAL
D3DCOLORVALUE Diffuse; //漫反射光颜色
D3DCOLORVALUE Specular; //镜面反射光颜色
D3DCOLORVALUE Ambient; //环境光颜色
D3DVECTOR Position; //光源位置，方向光该参数无意义
D3DVECTOR Direction; //方向，点光源无意义
float Range; //最大光程，方向光无意义
float Falloff; //聚光灯从内到外的衰减程度
float Attenuation0;
float Attenuation1;
float Attenuation2; //点光源和聚光灯随距离光强的衰减方式
float Theta; // 聚光灯内角
float Phi; // 聚光灯外角
} D3DLIGHT9, *LPD3DLIGHT;
光源设置完之后 需要注册，dx维护了一个光源列表
device->SetLight(0,&light);
注册完之后 可以进行控制
device->LightEnable();
5.5场景添加光源的方法：
1启用光照
2创建材质，设置材质
3创建光源，打开光源
4启用其余光源
代码：
#include "d3dUtility.h"
//
// Globals
//
IDirect3DDevice9* Device = 0;
const int Width = 640;
const int Height = 480;
IDirect3DVertexBuffer9* Pyramid = 0;
//
// Classes and Structures
//
struct Vertex
{
Vertex(){}
Vertex(float x, float y, float z, float nx, float ny, float nz)
{
_x = x; _y = y; _z = z;
_nx = nx; _ny = ny; _nz = nz;
}
float _x, _y, _z;
float _nx, _ny, _nz;
static const DWORD FVF;
};
const DWORD Vertex::FVF = D3DFVF_XYZ | D3DFVF_NORMAL;
//
// Framework Functions
//
bool Setup()
{
//
// Turn on lighting.
//
Device->SetRenderState(D3DRS_LIGHTING, true);
//
// Create the vertex buffer for the pyramid.
//
Device->CreateVertexBuffer(
12 * sizeof(Vertex),
D3DUSAGE_WRITEONLY,
Vertex::FVF,
D3DPOOL_MANAGED,
&Pyramid,
0);
//
// Fill the vertex buffer with pyramid data.
//
Vertex* v;
Pyramid->Lock(0, 0, (void**)&v, 0);
// front face
v[0] = Vertex(-1.0f, 0.0f, -1.0f, 0.0f, 0.707f, -0.707f);
v[1] = Vertex( 0.0f, 1.0f, 0.0f, 0.0f, 0.707f, -0.707f);
v[2] = Vertex( 1.0f, 0.0f, -1.0f, 0.0f, 0.707f, -0.707f);
// left face
v[3] = Vertex(-1.0f, 0.0f, 1.0f, -0.707f, 0.707f, 0.0f);
v[4] = Vertex( 0.0f, 1.0f, 0.0f, -0.707f, 0.707f, 0.0f);
v[5] = Vertex(-1.0f, 0.0f, -1.0f, -0.707f, 0.707f, 0.0f);
// right face
v[6] = Vertex( 1.0f, 0.0f, -1.0f, 0.707f, 0.707f, 0.0f);
v[7] = Vertex( 0.0f, 1.0f, 0.0f, 0.707f, 0.707f, 0.0f);
v[8] = Vertex( 1.0f, 0.0f, 1.0f, 0.707f, 0.707f, 0.0f);
// back face
v[9] = Vertex( 1.0f, 0.0f, 1.0f, 0.0f, 0.707f, 0.707f);
v[10] = Vertex( 0.0f, 1.0f, 0.0f, 0.0f, 0.707f, 0.707f);
v[11] = Vertex(-1.0f, 0.0f, 1.0f, 0.0f, 0.707f, 0.707f);
Pyramid->Unlock();
//
// Create and set the material.
//
D3DMATERIAL9 mtrl;
mtrl.Ambient = d3d::WHITE;
mtrl.Diffuse = d3d::WHITE;
mtrl.Specular = d3d::WHITE;
mtrl.Emissive = d3d::BLACK;
mtrl.Power = 5.0f;
Device->SetMaterial(&mtrl);
//
// Setup a directional light.
//
D3DLIGHT9 dir;
::ZeroMemory(&dir, sizeof(dir));
dir.Type = D3DLIGHT_DIRECTIONAL;
dir.Diffuse = d3d::RED;
dir.Specular = d3d::WHITE * 0.3f;
dir.Ambient = d3d::WHITE * 0.6f;
dir.Direction = D3DXVECTOR3(1.0f, 0.0f, 0.0f);
//
// Set and Enable the light.
//
Device->SetLight(0, &dir);
Device->LightEnable(0, true);
//
// Turn on specular lighting and instruct Direct3D
// to renormalize normals.
//
Device->SetRenderState(D3DRS_NORMALIZENORMALS, true);
Device->SetRenderState(D3DRS_SPECULARENABLE, false);
//
// Position and aim the camera.
//
D3DXVECTOR3 pos(0.0f, 1.0f, -3.0f);
D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);
D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);
D3DXMATRIX V;
D3DXMatrixLookAtLH(&V, &pos, &target, &up);
Device->SetTransform(D3DTS_VIEW, &V);
//
// Set the projection matrix.
//
D3DXMATRIX proj;
D3DXMatrixPerspectiveFovLH(
&proj,
D3DX_PI * 0.5f, // 90 - degree
(float)Width / (float)Height,
1.0f,
1000.0f);
Device->SetTransform(D3DTS_PROJECTION, &proj);
return true;
}
void Cleanup()
{
d3d::Release<IDirect3DVertexBuffer9*>(Pyramid);
}
bool Display(float timeDelta)
{
if( Device )
{
//
// Update the scene: Rotate the pyramid.
//
D3DXMATRIX yRot;
static float y = 0.0f;
D3DXMatrixRotationY(&yRot, y);
y += timeDelta;
if( y >= 6.28f )
y = 0.0f;
Device->SetTransform(D3DTS_WORLD, &yRot);
//
// Draw the scene:
//
Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0x00000000, 1.0f, 0);
Device->BeginScene();
Device->SetStreamSource(0, Pyramid, 0, sizeof(Vertex));
Device->SetFVF(Vertex::FVF);
Device->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 4);
Device->EndScene();
Device->Present(0, 0, 0, 0);
}
return true;
}
//
// WndProc
//
LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
switch( msg )
{
case WM_DESTROY:
::PostQuitMessage(0);
break;
case WM_KEYDOWN:
if( wParam == VK_ESCAPE )
::DestroyWindow(hwnd);
break;
}
return ::DefWindowProc(hwnd, msg, wParam, lParam);
}
//
// WinMain
//
int WINAPI WinMain(HINSTANCE hinstance,
HINSTANCE prevInstance,
PSTR cmdLine,
int showCmd)
{
if(!d3d::InitD3D(hinstance,
Width, Height, true, D3DDEVTYPE_HAL, &Device))
{
::MessageBox(0, "InitD3D() - FAILED", 0, 0);
return 0;
}
if(!Setup())
{
::MessageBox(0, "Setup() - FAILED", 0, 0);
return 0;
}
d3d::EnterMsgLoop( Display );
Cleanup();
Device->Release();
return 0;
}
