Автор: Daddy
WEB-сайт: http://daddy.mirgames.ru

Отрисовка двигающегося треугольника.

Привет! В этом уроке я объясню как нарисовать треугольник в OpenGL. Здесь нам понадобиться материал из первого урока(кроме Main). Функция WinMain остаётся неизменной так как она находится в Init Main и End. Давайте начнём с Init:

#include  // include matrix lib to handle matrix stuff

void Init()
{
	KernelServer = new nKernelServer;
	GfxServer = (nGfxServer *) ks->New("nglserver","/sys/servers/gfx");
	InputServer = (nInputServer *) ks->New("ninputserver","/sys/servers/input");
	
	// these remain unchanged
	KernelServer->ts->EnableFrameTime();

	//enable the frametime counter
	//the Kernel server class has a member
	//of nTimeServer class that handles time ,
	//profiling etc called 'ts' (bad name)

	InputServer->BeginMap();
	InputServer->Map("keyb0:left.pressed", "decreasex");
	InputServer->Map("keyb0:right.pressed", "increasex");
	InputServer->Map("keyb0:up.pressed", "increasey");
	InputServer->Map("keyb0:down.pressed", "decreasey");
	InputServer->Map("keyb0:esc.up", "end");
	InputServer->EndMap();

	GfxServer->SetDisplayMode("-type(win)-w(640)-h(480)");
	GfxServer->SetClearColor(0.7f,0.7f,0.7f,1.0f);
	GfxServer->SetViewVolume(-100, 100, -100, 100, 0, 100);

	// NEW. We have to set the view volume so that polys dont get culled
	GfxServer->OpenDisplay();
}
 
Теперь Main Здесь мы рисуем треугольник void Main()
{
	static float rangle = 0.0f, // rotation angle for the triangle
	xpos=0.0f, // xpos for the tri
	ypos=0.0f, // ypos for the tri
	LastFrameTime=0.0f; // var to track time

	InputServer->Trigger();

	if(!GfxServer->Trigger()) 
		EndProgram();

	KernelServer->ts->Trigger();

	// Do Internal work, quit if needed, update times , etc;

	if (InputServer->GetButton("end")) 
	{
		EndProgram();
		return;
	}
	if (InputServer->GetButton("decreasex")) xpos-=0.01f;
	if (InputServer->GetButton("increasex")) xpos+=0.01f;
	if (InputServer->GetButton("decreasey")) ypos-=0.01f;
	if (InputServer->GetButton("increasey")) ypos+=0.01f;

	// if flags were fired, execute
	// correspondant action

	GfxServer->BeginScene();

	// tell the GfxServer and correspondant API(GL or DX)
	// that we are going to draw

	nRState RenderState;
	RenderState.Set(N_RS_CULLMODE,N_CULL_NONE);

	GfxServer->SetState(RenderState);
	// Init a renderstate block and disable Culling so that
	// when the poligon turns it doesnt get culled

	static matrix44 Transform;
	TransformMatrix.ident();
	
	// create a matrix to handle the
	// transformation operations and set it to
	// the identity
	
	rangle+=0.01f;
	// increase polygon rotation angle

	Transform.rotate_y(rangle);
	Transform.rotate_x(rangle*0.5f);
	Transform.rotate_z(rangle*0.75f);
	Transform.translate(vector3(xpos,ypos,0));
	// create a matrix which will rotate the points then
	// translate 'em by xpos and ypos
	
	GfxServer->SetMatrix(N_MXM_MODELVIEW,Transform);
	// set the ModelView matrix to our matrix

	GfxServer->Begin(N_PTYPE_TRIANGLE_LIST);
	GfxServer->Rgba(1.0f,0.0f,0.0f,1.0f);
	GfxServer->Coord(0.25, 0.0f, -0.25f);
	GfxServer->Rgba(0.0f,1.0f,0.0f,1.0f);
	GfxServer->Coord(0.25, 0.0f, +0.25f);
	GfxServer->Rgba(0.0f,0.0f,1.0f,1.0f);
	GfxServer->Coord(-0.25f, 0.0f, 0.25);
	GfxServer->End();

	char str[80];
	double fps = 1/(KernelServer->ts->GetFrameTime()-LastFrameTime);
	sprintf(str,"FPS:%f",fps);
	// calculate the fps through GetFrameTime() and LastFrameTime
	// and print it to str

	GfxServer->BeginText(); // Tell him that we're gonna draw text
	GfxServer->TextPos(-1,-1); // Set the Text output position
	GfxServer->Text(str); // send the string and draw it
	GfxServer->EndText(); // end the draw text block
	GfxServer->EndScene(); // End drawing (update screen,clear,etc)

	LastFrameTime = KernelServer->ts->GetFrameTime(); 
	// set last frame time

	// NOTE: GetFrameTime() here will return the same as it has returned when
	// we have calculated the fps cause it returns a var which is only updated
	// in InputServer->Trigger()
}

Конец остаётся тем же самым так как мы не добавили никакого нового интерфейса. Попробуйте это, нажмите кнопку мыши и треугольник будет двигаться. FPS просто потрясает!

Исходник можно скачать тут: tutor2.rar