本篇是创建游戏内核(7)【OO改良版】的续篇,关于该内核的细节说明请参阅创建游戏内核(8)。
接口:
class LIGHT
{
public:
    LIGHT();
    D3DLIGHT9* get_light();
    void init();
    void set_type(D3DLIGHTTYPE type);
    void move(float x_pos, float y_pos, float z_pos);
    void move_rel(float x_pos, float y_pos, float z_pos);
    void get_pos(float* x_pos, float* y_pos, float* z_pos);
    void point(float x_from, float y_from, float z_from, float x_at, float y_at, float z_at);
    void get_direction(float* x_dir, float* y_dir, float* z_dir);
    void set_diffuse(unsigned char red, unsigned char green, unsigned char blue);
    void get_diffuse(unsigned char* red, unsigned char* green, unsigned char* blue);
    void set_specular(unsigned char red, unsigned char green, unsigned char blue);
    void get_specular(unsigned char* red, unsigned char* green, unsigned char* blue);
    
    void set_ambient(unsigned char red, unsigned char green, unsigned char blue);
    void get_ambient(unsigned char* red, unsigned char* green, unsigned char* blue);
    void  set_range(float range);
    float get_range();
    void  set_falloff(float falloff);
    float get_falloff();
    void  set_attenuation_0(float attenuation);
    float get_attenuation_0();
    void  set_attenuation_1(float attenuation);
    float get_attenuation_1();    
    void  set_attenuation_2(float attenuation);
    float get_attenuation_2();
    void  set_theta(float theta);
    float get_theta();
    void  set_phi(float phi);
    float get_phi();
private:
    D3DLIGHT9 m_light;
};
typedef LIGHT* LIGHT_PTR;
 
实现:
//---------------------------------------------------------------------------
// Constructor, zero member data.
//---------------------------------------------------------------------------
LIGHT::LIGHT()
{
    ZeroMemory(this, sizeof(*this));    
}
//---------------------------------------------------------------------------
// Set light type as point light, place light source at origin, and set diffuse 
// color and ambient color as white, set range and attenuation for light.
//---------------------------------------------------------------------------
void LIGHT::init()
{
    set_type(D3DLIGHT_POINT);
    
    set_diffuse(255, 255, 255);
    set_ambient(255, 255, 255);
    set_range(1000.0);
    set_attenuation_0(1.0);
    move(0.0, 0.0, 0.0);
}
//---------------------------------------------------------------------------
// set light type (D3DLIGHT_POINT, D3DLIGHT_SPOT, D3DLIGHT_DIRECTIONAL).
//---------------------------------------------------------------------------
void LIGHT::set_type(D3DLIGHTTYPE type)
{
    m_light.Type = type;
}
//---------------------------------------------------------------------------
// move light source to specified position.
//---------------------------------------------------------------------------
void LIGHT::move(float x_pos, float y_pos, float z_pos)
{
    m_light.Position.x = x_pos;
    m_light.Position.y = y_pos;
    m_light.Position.z = z_pos;
}
//---------------------------------------------------------------------------
// move light source to specified position which is relative to current position.
//---------------------------------------------------------------------------
void LIGHT::move_rel(float x_pos, float y_pos, float z_pos)
{
    m_light.Position.x += x_pos;
    m_light.Position.y += y_pos;
    m_light.Position.z += z_pos;
}
//---------------------------------------------------------------------------
// Get current position.
//---------------------------------------------------------------------------
void LIGHT::get_pos(float *x_pos, float *y_pos, float *z_pos)
{
    if(x_pos != NULL)
        *x_pos = m_light.Position.x;
    if(y_pos != NULL)
        *y_pos = m_light.Position.y;
    if(z_pos != NULL)
        *z_pos = m_light.Position.z;
}
//---------------------------------------------------------------------------
// move light source to specified position and pointer it to specified direction.
//---------------------------------------------------------------------------
void LIGHT::point(float x_from, float y_from, float z_from, 
                  float x_at, float y_at, float z_at)
{
    // move the light
    move(x_from, y_from, z_from);
    // calculate vetor between angles
    m_light.Direction.x = x_at - x_from;
    m_light.Direction.y = y_at - y_from;
    m_light.Direction.z = z_at - z_from;
}
//---------------------------------------------------------------------------
// Get the direction of current light source.
//---------------------------------------------------------------------------
void LIGHT::get_direction(float *x_dir, float *y_dir, float *z_dir)
{
    if(x_dir != NULL)
        *x_dir = m_light.Direction.x;
    if(y_dir != NULL)
        *y_dir = m_light.Direction.y;
    if(z_dir != NULL)
        *z_dir = m_light.Direction.z;
}
//---------------------------------------------------------------------------
// set diffuse color of light source.
//---------------------------------------------------------------------------
void LIGHT::set_diffuse(unsigned char red, unsigned char green, unsigned char blue)
{
    m_light.Diffuse.r = red / 255.0f;
    m_light.Diffuse.g = green / 255.0f;
    m_light.Diffuse.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get diffuse color of light source.
//---------------------------------------------------------------------------
void LIGHT::get_diffuse(unsigned char* red, unsigned char* green, unsigned char* blue)
{
    if(red != NULL)
        *red = (unsigned char)(255.0f * m_light.Diffuse.r);
    if(green != NULL)
        *green = (unsigned char)(255.0f * m_light.Diffuse.g);
    if(blue != NULL)
        *blue = (unsigned char)(255.0f * m_light.Diffuse.b);
}
//---------------------------------------------------------------------------
// set specular color of light source.
//---------------------------------------------------------------------------
void LIGHT::set_specular(unsigned char red, unsigned char green, unsigned char blue)
{
    m_light.Specular.r = red / 255.0f;
    m_light.Specular.g = green / 255.0f;
    m_light.Specular.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get specular color of light source.
//---------------------------------------------------------------------------
void LIGHT::get_specular(unsigned char* red, unsigned char* green, unsigned char* blue)
{
    if(red != NULL)
        *red = (unsigned char)(255.0f * m_light.Specular.r);
    if(green != NULL)
        *green = (unsigned char)(255.0f * m_light.Specular.g);
    if(blue != NULL)
        *blue = (unsigned char)(255.0f * m_light.Specular.b);
}
//---------------------------------------------------------------------------
// set ambient color of light source.
//---------------------------------------------------------------------------
void LIGHT::set_ambient(unsigned char red, unsigned char green, unsigned char blue)
{
    m_light.Ambient.r = red / 255.0f;
    m_light.Ambient.g = green / 255.0f;
    m_light.Ambient.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get ambient color of light source.
//---------------------------------------------------------------------------
void LIGHT::get_ambient(unsigned char* red, unsigned char* green, unsigned char* blue)
{
    if(red != NULL)
        *red = (unsigned char)(255.0f * m_light.Ambient.r);
    if(green != NULL)
        *green = (unsigned char)(255.0f * m_light.Ambient.g);
    if(blue != NULL)
        *blue = (unsigned char)(255.0f * m_light.Ambient.b);
}
//---------------------------------------------------------------------------
// set the range of light source.
//---------------------------------------------------------------------------
void LIGHT::set_range(float range)
{
    m_light.Range = range;
}
//---------------------------------------------------------------------------
// Get the range of light source.
//---------------------------------------------------------------------------
float LIGHT::get_range()
{
    return m_light.Range;
}
//---------------------------------------------------------------------------
// set the fallof of light source.
//---------------------------------------------------------------------------
void LIGHT::set_falloff(float falloff)
{
    m_light.Falloff = falloff;
}
//---------------------------------------------------------------------------
// Get the fallof of light source.
//---------------------------------------------------------------------------
float LIGHT::get_falloff()
{
    return m_light.Falloff;
}
//---------------------------------------------------------------------------
// set attenuation 0 of light source.
//---------------------------------------------------------------------------
void LIGHT::set_attenuation_0(float attenuation)
{
    m_light.Attenuation0 = attenuation;
}
//---------------------------------------------------------------------------
// Get attenuation 0 of light source.
//---------------------------------------------------------------------------
float LIGHT::get_attenuation_0()
{
    return m_light.Attenuation0;
}
//---------------------------------------------------------------------------
// set attenuation 1 of light source.
//---------------------------------------------------------------------------
void LIGHT::set_attenuation_1(float attenuation)
{
    m_light.Attenuation1 = attenuation;
}
//---------------------------------------------------------------------------
// Get attenuation 1 of light source.
//---------------------------------------------------------------------------
float LIGHT::get_attenuation_1()
{
    return m_light.Attenuation1;
}
//---------------------------------------------------------------------------
// set attenuation 2 of light source.
//---------------------------------------------------------------------------
void LIGHT::set_attenuation_2(float attenuation)
{
    m_light.Attenuation2 = attenuation;
}
//---------------------------------------------------------------------------
// Get attenuation 2 of light source.
//---------------------------------------------------------------------------
float LIGHT::get_attenuation_2()
{
    return m_light.Attenuation2;
}
//---------------------------------------------------------------------------
// set angle thera of light source.
//---------------------------------------------------------------------------
void LIGHT::set_theta(float theta)
{
    m_light.Theta = theta;
}
//---------------------------------------------------------------------------
// Get angle thera of light source.
//---------------------------------------------------------------------------
float LIGHT::get_theta()
{
    return m_light.Theta;
}
//---------------------------------------------------------------------------
// set angle phi of light source.
//---------------------------------------------------------------------------
void LIGHT::set_phi(float phi)
{
    m_light.Phi = phi;
}
//---------------------------------------------------------------------------
// Get angle phi of light source.
//---------------------------------------------------------------------------
float LIGHT::get_phi()
{
    return m_light.Phi;
}
//---------------------------------------------------------------------------
// Get light source.
//---------------------------------------------------------------------------
D3DLIGHT9* LIGHT::get_light()
{
    return &m_light;
}
 
测试代码:
/*****************************************************************************
PURPOSE:
    Test for class LIGHT.
*****************************************************************************/
#include "core_common.h"
#include "core_framework.h"
#include "core_graphics.h"
// The 3D vertex format and descriptor
typedef struct
{
    float x, y, z;      // 3D coordinates    
    float nx, ny, nz;   // normals
    D3DCOLOR diffuse;   // color
} VERTEX;
#define VERTEX_FVF   (D3DFVF_XYZ | D3DFVF_NORMAL | D3DFVF_DIFFUSE)
class APP : public FRAMEWORK
{
public:
    BOOL init()
    {
        // initialize vertex data
        VERTEX _verts[] = {
            { -100.0f,  100.0f, -100.0f, 0.0f,0.0f,-1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f,  100.0f, -100.0f, 0.0f,0.0f,-1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f, -100.0f, -100.0f, 0.0f,0.0f,-1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f, -100.0f, -100.0f, 0.0f,0.0f,-1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f,  100.0f, -100.0f, 1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f,  100.0f,  100.0f, 1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f, -100.0f, -100.0f, 1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f, -100.0f,  100.0f, 1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f,  100.0f,  100.0f, 0.0f,0.0f,1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f,  100.0f,  100.0f, 0.0f,0.0f,1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            {  100.0f, -100.0f,  100.0f, 0.0f,0.0f,1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f, -100.0f,  100.0f, 0.0f,0.0f,1.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f,  100.0f,  100.0f, -1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f,  100.0f, -100.0f, -1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f, -100.0f,  100.0f, -1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) },
            { -100.0f, -100.0f, -100.0f, -1.0f,0.0f,0.0f, D3DCOLOR_RGBA(255,255,255,255) }
        }; 
        // Create Direct3D and Direct3DDevice object
        if(! create_display(g_hwnd, get_client_width(g_hwnd), get_client_height(g_hwnd), 16, TRUE, FALSE))
            return FALSE;
        // builds a left-handed perspective projection matrix based on a field of view
        set_perspective(D3DX_PI/4.0, 1.33333f, 1.0f, 1000.0f);
        D3DXMATRIX _mat_view;
        // create and set the view matrix
        D3DXMatrixLookAtLH(&_mat_view, 
                           &D3DXVECTOR3(0.0f, 0.0f, -500.0f),
                           &D3DXVECTOR3(0.0f, 0.0f, 0.0f), 
                           &D3DXVECTOR3(0.0f, 1.0f, 0.0f));
        g_d3d_device->SetTransform(D3DTS_VIEW, &_mat_view);
        BYTE* _vertex_ptr;
        // create the vertex buffer and set data
        g_d3d_device->CreateVertexBuffer(sizeof(_verts), 0, VERTEX_FVF, D3DPOOL_DEFAULT, &m_vertex_buffer, NULL);     
        // locks a range of vertex data and obtains a pointer to the vertex buffer memory
        m_vertex_buffer->Lock(0, 0, (void**)&_vertex_ptr, 0);
        memcpy(_vertex_ptr, _verts, sizeof(_verts));
        // unlocks vertex data
        m_vertex_buffer->Unlock();
        // enable d3d lighting
        g_d3d_device->SetRenderState(D3DRS_LIGHTING, TRUE); 
        LIGHT _light;    
        // set light
        _light.init();
        _light.set_type(D3DLIGHT_POINT);
        _light.set_diffuse(128, 128, 0);
        _light.set_range(1000.0);
        _light.set_attenuation_0(0.5);
        _light.move(300.0, 0.0, -600.0);
        
        // attach light to d3d device and enable _light
        g_d3d_device->SetLight(0, _light.get_light());    
        // enale this light
        g_d3d_device->LightEnable(0, TRUE);
        return TRUE;
    }
    BOOL frame()
    {
        clear_display_buffer(D3DCOLOR_RGBA(0, 0, 0, 0));
        if(SUCCEEDED(g_d3d_device->BeginScene()))
        {
            D3DXMATRIX _mat_world;
            // create and set the world transformation matrix
            // rotate object along y-axis
            D3DXMatrixRotationY(&_mat_world, (float) (timeGetTime() / 1000.0));
            g_d3d_device->SetTransform(D3DTS_WORLD, &_mat_world);
            // set the vertex stream, shader, and texture.
            // binds a vertex buffer to a device data stream
            g_d3d_device->SetStreamSource(0, m_vertex_buffer, 0, sizeof(VERTEX));
            // set the current vertex stream declation
            g_d3d_device->SetFVF(VERTEX_FVF);
            // renders a sequence of noindexed, geometric primitives of the specified type from the current set
            // of data input stream.
            for(short i = 0; i < 4; i++)
                g_d3d_device->DrawPrimitive(D3DPT_TRIANGLESTRIP, i * 4, 2);
            
            g_d3d_device->EndScene();
        }
        present_display();
        return TRUE;
    }
    BOOL shutdown()
    {
        release_com(m_vertex_buffer);
        release_com(g_d3d_device);
        release_com(g_d3d);
        return TRUE;
    }
    
private:
    IDirect3DVertexBuffer9* m_vertex_buffer;
};
//--------------------------------------------------------------------------------
// Main function, routine entry.
//--------------------------------------------------------------------------------
int WINAPI WinMain(HINSTANCE inst, HINSTANCE pre_inst, LPSTR cmd_line, int cmd_show)
{
    APP app;
    if(! build_window(inst, "MainClass", "MainWindow", WS_OVERLAPPEDWINDOW, 0, 0, 640, 480))
        return -1;
    
    app.run();
    return 0;
}