下載源碼和工程
3D圖形引擎的代碼以創(chuàng)建游戲內(nèi)核中編寫的代碼為基礎(chǔ)進(jìn)行開(kāi)發(fā)。
使用單一的網(wǎng)格模型雖然可以同時(shí)渲染整個(gè)層次，但卻意味著那些沒(méi)有被看到的部分在通過(guò)渲染管道時(shí)會(huì)被裁剪掉，也就是說(shuō)這樣做會(huì)浪費(fèi)時(shí)間。不要沮喪，因?yàn)槭褂靡粋€(gè)單獨(dú)的網(wǎng)格模型進(jìn)行層次的渲染仍然有一些非常好的方法。比如說(shuō)，在游戲世界中包括了單獨(dú)的地牢，每個(gè)地牢包含不同的房間，所有的房間通過(guò)走廊連接到一起。其實(shí)，每個(gè)房間和走廊就是一個(gè)單獨(dú)的網(wǎng)格模型，所要做的就是在游戲的處理過(guò)程中加載以及釋放那些代表地牢房間的網(wǎng)格模型。
我們首先定義一些成員變量來(lái)存儲(chǔ)數(shù)據(jù)。
class APP : public APPLICATION
{
private:
GRAPHICS _graphics;
CAMERA _camera;
INPUT _input;
INPUT_DEVICE _keyboard;
INPUT_DEVICE _mouse;
MESH _room_meshes[2];
OBJECT _room_objects[8];
float _x_pos, _z_pos;
}
初始化窗口：
APP()
{
_width = 640;
_height = 480;
_style = WS_BORDER | WS_CAPTION | WS_MINIMIZEBOX | WS_SYSMENU;
strcpy(_class_name, "mesh level class");
strcpy(_caption, "mesh level demo");
}
加載網(wǎng)格模型：
BOOL init()
{
// initialize graphics and set display mode
_graphics.init();
_graphics.set_mode(get_hwnd(), TRUE, TRUE);
_graphics.set_perspective(D3DX_PI / 4, 1.3333f, 1.0f, 10000.0f);
// initialize input and input device
_input.init(get_hwnd(), get_inst());
_keyboard.create(&_input, KEYBOARD);
_mouse.create(&_input, MOUSE, TRUE);
// load the room meshes
_room_meshes[0].load(&_graphics, "..\\Data\\Corridor.x", "..\\Data\\");
_room_meshes[1].load(&_graphics, "..\\Data\\Room.x", "..\\Data\\");
// setup the room objects
_room_objects[0].create(&_graphics, &_room_meshes[1]);
_room_objects[1].create(&_graphics, &_room_meshes[0]);
_room_objects[2].create(&_graphics, &_room_meshes[1]);
_room_objects[3].create(&_graphics, &_room_meshes[0]);
_room_objects[4].create(&_graphics, &_room_meshes[0]);
_room_objects[5].create(&_graphics, &_room_meshes[1]);
_room_objects[6].create(&_graphics, &_room_meshes[0]);
_room_objects[7].create(&_graphics, &_room_meshes[1]);
// place room object in specified position
_room_objects[0].move(-2000.0f, 0.0f, 2000.0f);
_room_objects[1].move( 0.0f, 0.0f, 2000.0f);
_room_objects[2].move( 2000.0f, 0.0f, 2000.0f);
_room_objects[3].move(-2000.0f, 0.0f, 0.0f);
_room_objects[4].move( 2000.0f, 0.0f, 0.0f);
_room_objects[5].move(-2000.0f, 0.0f, -2000.0f);
_room_objects[6].move( 0.0f, 0.0f, -2000.0f);
_room_objects[7].move( 2000.0f, 0.0f, -2000.0f);
// rotate room object into proper orientation
_room_objects[1].rotate(0.0f, 1.57f, 0.0f);
_room_objects[2].rotate(0.0f, 1.57f, 0.0f);
_room_objects[5].rotate(0.0f, -1.57f, 0.0f);
_room_objects[6].rotate(0.0f, -1.57f, 0.0f);
_room_objects[7].rotate(0.0f, 3.14f, 0.0f);
// position view in a room
_x_pos = -2000.0f;
_z_pos = -2000.0f;
return TRUE;
}
這里加載了兩個(gè)網(wǎng)格模型corridor.x 和room.x，一個(gè)是走廊，一個(gè)是房間。
走廊：
房間：
游戲中的每個(gè)走廊和房間都使用了一個(gè)OBJECT對(duì)象，其與網(wǎng)格模型依次相關(guān)聯(lián)。
我們接著來(lái)看看如何渲染這些網(wǎng)格模型。
BOOL frame()
{
static DWORD time_now = timeGetTime();
// calculate elapsed time (plus speed boost)
ulong time_elapsed = (timeGetTime() - time_now) * 2;
time_now = timeGetTime();
// read input device data
_keyboard.read();
_mouse.read();
// process input and update everything, ESC quits program.
if(_keyboard.get_key_state(KEY_ESC))
return FALSE;
float x_move = 0.0f;
float z_move = 0.0f;
// ok, now let me explain next codes.
//
// _camera.get_y_rotation():
// get camera vector in xoz plane.
//
// sin(_camera.get_y_rotation()):
// get x-coordinate of camera vector.
//
// cos(_camera.get_y_rotation()):
// get z-coordinate of camera vector.
// move viewpoint forward
if(_keyboard.get_key_state(KEY_UP))
{
x_move = (float) sin(_camera.get_y_rotation()) * time_elapsed;
z_move = (float) cos(_camera.get_y_rotation()) * time_elapsed;
}
// move viewpoint backward
if(_keyboard.get_key_state(KEY_DOWN))
{
x_move = -(float) sin(_camera.get_y_rotation()) * time_elapsed;
z_move = -(float) cos(_camera.get_y_rotation()) * time_elapsed;
}
// translate camera left-right movement into up-down movement.
//
// _camera.get_y_rotation() - 1.57f:
// rotate camera 90 degree anticlockwise.
//
// sin(_camera.get_y_rotation() - 1.57f):
// get x-coordinate of camera vector after camera rotation.
//
// cos(_camera.get_y_rotation() - 1.57f):
// get z-coordinate of camera vector after camera rotation.
// move viewpoint left
if(_keyboard.get_key_state(KEY_LEFT))
{
x_move = (float) sin(_camera.get_y_rotation() - 1.57f) * time_elapsed;
z_move = (float) cos(_camera.get_y_rotation() - 1.57f) * time_elapsed;
}
// _camera.get_y_rotation() + 1.57f:
// rotate camera 90 degree clockwise.
//
// sin(_camera.get_y_rotation() + 1.57f):
// get x-coordinate of camera vector after camera rotation.
//
// cos(_camera.get_y_rotation() + 1.57f):
// get z-coordinate of camera vector after camera rotation.
// move viewpoint right
if(_keyboard.get_key_state(KEY_RIGHT))
{
x_move = (float) sin(_camera.get_y_rotation() + 1.57f) * time_elapsed;
z_move = (float) cos(_camera.get_y_rotation() + 1.57f) * time_elapsed;
}
// update view coordinates
_x_pos += x_move;
_z_pos += z_move;
// position camera and rotate based on mouse position
_camera.move(_x_pos, 400.0f, _z_pos);
// _mouse.get_y_delta():
// get mouse's relative x movement coordinate.
//
// _mouse.get_x_delta():
// get mouse's relative y movement coordinate.
_camera.rotate_rel(_mouse.get_y_delta() / 200.0f, _mouse.get_x_delta() / 200.0f, 0.0f);
// set camera
_graphics.set_camera(&_camera);
// render everything
_graphics.clear(D3DCOLOR_RGBA(0, 64, 128, 255));
// begin render now
if(_graphics.begin_scene())
{
// render each room
for(short i = 0; i < 8; i++)
_room_objects[i].render();
_graphics.end_scene();
}
_graphics.display();
return TRUE;
}
用上下左右鍵控制相機(jī)的位置，用鼠標(biāo)控制相機(jī)的朝向。
截圖：
