本篇是创建游戏内核（7）【C风格版】的续篇，关于该内核的细节说明请参考创建游戏内核（8）。
接口：
void move_light(D3DLIGHT9_PTR light,
float x_pos, float y_pos, float z_pos);
void move_light_rel(D3DLIGHT9_PTR light,
float x_pos, float y_pos, float z_pos);
void get_light_pos(const D3DLIGHT9_PTR light,
float_ref x_pos, float_ref y_pos, float_ref z_pos);
void point_light(D3DLIGHT9_PTR light,
float x_from, float y_from, float z_from,
float x_at, float y_at, float z_at);
void get_light_direction(const D3DLIGHT9_PTR light,
float_ref x_dir, float_ref y_dir, float_ref z_dir);
void set_light_diffuse(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue);
void get_light_diffuse(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue);
void set_light_specular(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue);
void get_light_specular(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue);
void set_light_ambient(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue);
void get_light_ambient(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue);
实现：
//---------------------------------------------------------------------------
// move light source to specified position.
//---------------------------------------------------------------------------
void move_light(D3DLIGHT9_PTR light,
float x_pos, float y_pos, float z_pos)
{
light->Position.x = x_pos;
light->Position.y = y_pos;
light->Position.z = z_pos;
}
//---------------------------------------------------------------------------
// move light source to specified position which is relative to current position.
//---------------------------------------------------------------------------
void move_light_rel(D3DLIGHT9_PTR light,
float x_pos, float y_pos, float z_pos)
{
light->Position.x += x_pos;
light->Position.y += y_pos;
light->Position.z += z_pos;
}
//---------------------------------------------------------------------------
// Get current position.
//---------------------------------------------------------------------------
void get_light_pos(const D3DLIGHT9_PTR light,
float_ref x_pos, float_ref y_pos, float_ref z_pos)
{
x_pos = light->Position.x;
y_pos = light->Position.y;
z_pos = light->Position.z;
}
//---------------------------------------------------------------------------
// move light source to specified position and pointer it to specified direction.
//---------------------------------------------------------------------------
void point_light(D3DLIGHT9_PTR light,
float x_from, float y_from, float z_from,
float x_at, float y_at, float z_at)
{
// move the light
move_light(light, x_from, y_from, z_from);
// calculate vector between angles
light->Direction.x = x_at - x_from;
light->Direction.y = y_at - y_from;
light->Direction.z = z_at - z_from;
}
//---------------------------------------------------------------------------
// Get the direction of current light source.
//---------------------------------------------------------------------------
void get_light_direction(const D3DLIGHT9_PTR light,
float_ref x_dir, float_ref y_dir, float_ref z_dir)
{
x_dir = light->Direction.x;
y_dir = light->Direction.y;
z_dir = light->Direction.z;
}
//---------------------------------------------------------------------------
// set diffuse color of light source.
//---------------------------------------------------------------------------
void set_light_diffuse(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue)
{
light->Diffuse.r = red / 255.0f;
light->Diffuse.g = green / 255.0f;
light->Diffuse.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get diffuse color of light source.
//---------------------------------------------------------------------------
void get_light_diffuse(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue)
{
red = (uchar)(255.0f * light->Diffuse.r);
green = (uchar)(255.0f * light->Diffuse.g);
blue = (uchar)(255.0f * light->Diffuse.b);
}
//---------------------------------------------------------------------------
// set specular color of light source.
//---------------------------------------------------------------------------
void set_light_specular(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue)
{
light->Specular.r = red / 255.0f;
light->Specular.g = green / 255.0f;
light->Specular.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get specular color of light source.
//---------------------------------------------------------------------------
void get_light_specular(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue)
{
red = (uchar)(255.0f * light->Specular.r);
green = (uchar)(255.0f * light->Specular.g);
blue = (uchar)(255.0f * light->Specular.b);
}
//---------------------------------------------------------------------------
// set ambient color of light source.
//---------------------------------------------------------------------------
void set_light_ambient(D3DLIGHT9_PTR light,
uchar red, uchar green, uchar blue)
{
light->Ambient.r = red / 255.0f;
light->Ambient.g = green / 255.0f;
light->Ambient.b = blue / 255.0f;
}
//---------------------------------------------------------------------------
// Get ambient color of light source.
//---------------------------------------------------------------------------
void get_light_ambient(const D3DLIGHT9_PTR light,
uchar_ref red, uchar_ref green, uchar_ref blue)
{
red = (uchar)(255.0f * light->Ambient.r);
green = (uchar)(255.0f * light->Ambient.g);
blue = (uchar)(255.0f * light->Ambient.b);
}
测试代码：
/***********************************************************************************
PURPOSE:
Test D3D light function.
***********************************************************************************/
#include "core_common.h"
#include "core_framework.h"
#include "core_graphics.h"
#include "core_tool.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)
IDirect3DVertexBuffer9* g_vertex_buffer;
//--------------------------------------------------------------------------------
// Initialize data for game.
//--------------------------------------------------------------------------------
BOOL game_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_window_width(g_hwnd), get_window_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, &g_vertex_buffer, NULL);
// locks a range of vertex data and obtains a pointer to the vertex buffer memory
g_vertex_buffer->Lock(0, 0, (void**)&vertex_ptr, 0);
memcpy(vertex_ptr, verts, sizeof(verts));
// unlocks vertex data
g_vertex_buffer->Unlock();
// enable d3d lighting
g_d3d_device->SetRenderState(D3DRS_LIGHTING, TRUE);
D3DLIGHT9 light;
memset(&light, 0, sizeof(light));
// set light property
light.Type = D3DLIGHT_POINT;
light.Range = 1000.0f;
light.Attenuation0 = 0.5;
set_light_diffuse(&light, 128, 128, 0);
move_light(&light, 300.0, 0.0, -600.0);
// attach light to d3d device and enable light
g_d3d_device->SetLight(0, &light);
// enale this light
g_d3d_device->LightEnable(0, TRUE);
return TRUE;
}
//--------------------------------------------------------------------------------
// Render every game frame.
//--------------------------------------------------------------------------------
BOOL game_frame()
{
clear_display_buffer(D3DCOLOR_RGBA(0, 0, 0, 0));
if(SUCCEEDED(g_d3d_device->BeginScene()))
{
D3DXMATRIX mat_world;
// 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, g_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;
}
//--------------------------------------------------------------------------------
// Release all game resources.
//--------------------------------------------------------------------------------
BOOL game_shutdown()
{
release_com(g_vertex_buffer);
destroy_display();
return TRUE;
}
//--------------------------------------------------------------------------------
// Main function, routine entry.
//--------------------------------------------------------------------------------
int WINAPI WinMain(HINSTANCE inst, HINSTANCE pre_inst, LPSTR cmd_line, int cmd_show)
{
DWORD client_width = 640;
DWORD client_height = 480;
DWORD x_pos = (get_screen_width() - client_width) / 2;
DWORD y_pos = (get_screen_height() - client_height) / 4;
if(! build_window(inst, "light class", "light test", WS_OVERLAPPEDWINDOW,
x_pos, y_pos, client_width, client_height))
{
return -1;
}
run_game(game_init, game_frame, game_shutdown);
return 0;
}