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my first engine with steering code +problem

Started by Basiror 9 replies 250+ views
Original Post
Basiror
Basiror
http://www.planethalflife.com/borderline/members/basiror/bas3d.zip as you notice the move moves up and down but never stands still is that because i check the mouse position every frame? see underneath 
  
void CCamera::MoveCamera()
{
	int x;
	int y;
	float deltax;
	float deltay;
	x=1280/2;
	y=1028/2;
	POINT cursorpos;
	GetCursorPos(&cursorpos);
	SetCursorPos(1280/2,1024/2);
	if(x==cursorpos.x && y==cursorpos.y)
		return;
	deltax=(float)(x - cursorpos.x)*-0.01;
	deltay=(float)(y - cursorpos.y)*-0.01;
	
	gPlayer.viewangle[0] +=deltay * 4;//gPlayer.scrollratio;

	gPlayer.viewangle[1] +=deltax * 4;//gPlayer.scrollratio;

	gPlayer.viewangle[2]=0.0;
}

void CCamera::MovePlayer()
{
	vec3_t angle;
	VectorCopy(gPlayer.viewangle,angle);
	angle[0]=-angle[0];
	angle[1]+=90;
	AngleVectors(angle,forward,right,up);
	VectorNormalize(forward);
	VectorNormalize(right);
	VectorNormalize(up);
	if(gApp.IsKeyPressed(DIK_UP))
		VectorMA(gPlayer.origin,-10,forward,gPlayer.origin);
	if(gApp.IsKeyPressed(DIK_DOWN))
		VectorMA(gPlayer.origin,+10,forward,gPlayer.origin);
	if(gApp.IsKeyPressed(DIK_LEFT))
		VectorMA(gPlayer.origin,-7,right,gPlayer.origin);
	if(gApp.IsKeyPressed(DIK_RIGHT))
		VectorMA(gPlayer.origin,7,right,gPlayer.origin);
}
http://www.8ung.at/basiror/theironcross.html
JuNC
JuNC
I''m not downloading 1.4meg just for a random question, exactly what is the problem? I''m guessing that you are talking about the mouse cursor flickering up and down rather than being rock steady. This is due to the mouse event handling being done in a completely different place to your programs thread (probably a separate blocked thread or an interrupt basis). The windowing system draws the mouse cursor on a completely different time basis (probably directly it senses the movement) therefore the mouse cursor will be drawn at it''s new position then redrawn when you reset it. Just hide the mouse cursor if it bothers you.

If this isn''t the problem then sorry. The code looks like it should do what you mean it to do.
Basiror
Basiror
hm actually i hide the cursor ill see if i can find some additional information about it thx
http://www.8ung.at/basiror/theironcross.html
griffenjam
griffenjam
I think I know what your problem is.
The camera continues to move even after you stop moving the mouse?

If I am right about your problem then changing this

if(x==cursorpos.x && y==cursorpos.y)
return;
deltax=(float)(x - cursorpos.x)*-0.01;
deltay=(float)(y - cursorpos.y)*-0.01;

to this

if(x==cursorpos.x && y==cursorpos.y)
return;
if(x!=cursorpos.x)
deltax=(float)(x - cursorpos.x)*-0.01;
if(y!=cursorpos.y)
deltay=(float)(y - cursorpos.y)*-0.01;

This is because x can equal the x cursopos, while y doesn''t. In this situation your code moves both x and y. Now y equals corsorpos.y and x doesn''t, you kinda get caought in a loop there.

Jason Mickela
ICQ : 873518
Excuse my speling.

Vallejo Punk
The V-Town Have-Nots
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"I don''t have to take this, I''m going to where I''m appreciated, my mom''s house"
Basiror
Basiror
doesn t work

btw i disable the mouse cursor with ShowCursor(FALSE);
just for the case i have forgotten something in order to disable it
http://www.8ung.at/basiror/theironcross.html
JuNC
JuNC
griffenjam, that's actually *worse* than his way, your way deltax or deltay could be used uninitialized

Notice if x == cursorpos.x then (x - cursorpos.x) == 0.0, in which case deltax will not affect the outcome at all.

Ok, I've broken down and am downloading the code...

EDIT:

Ok, I see what the problem is now, the view continues to drift upwards no matter what happens, yes?

Hmm, I don't see why in that code, what about your rendering setup code?

As a side note: good work on the engine, an option to set the screen mode to less than 1280x1024 would be *very* useful, we don't all have 19" monitors

[edited by - JuNC on November 1, 2002 8:32:59 AM]
Basiror
Basiror 

  
	



gCamera.MoveCamera();
gCamera.MovePlayer();


	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);			// Clear The Screen And The Depth Buffer

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(90.0f,(GLfloat)1280/(GLfloat)1024,32.0f,60000.0f);
	//glRotatef(0.4,0,1,0);

	glRotatef(gPlayer.viewangle[0],1,0,0);
	glRotatef(gPlayer.viewangle[1],0,1,0);
	//glTranslatef(-gPlayer.origin[0],gPlayer.origin[2],-gPlayer.origin[1]);

	glTranslatef(-2000,-256,2000);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glEnable(GL_TEXTURE_2D);
	
	
	int i=0;
	int a=0;
	int s=2;
	int iMode=0;
	int iOldMode=0;
	vec3_t dir;
	vec3_t forward,right,up;
	AngleVectors(gPlayer.viewangle,forward,right,up);
	forward[0]=-forward[0];
	forward[1]=-forward[1];
	forward[2]=-forward[2];
	
	//if(gApp.polygonstack)

		//return;

	glBindTexture(GL_TEXTURE_2D, gApp.texture.texID);	
	float d;
	d=-DotProduct(gCamera.forward,gPlayer.origin);
	if(gApp.polygonstack){
	for(i=0;i<gApp.m_iPolygons;i++)
	{
		
		
			if(gApp.polygonstack[i].m_iVertices==3)
			{
				iMode=GL_TRIANGLES;
			}
			else if(gApp.polygonstack[i].m_iVertices==4)
			{
				iMode=GL_QUADS;
			}
			else if(gApp.polygonstack[i].m_iVertices>4)
			{
				iMode=GL_TRIANGLE_FAN;
			}
			if(gApp.polygonstack[i].m_iVertices>2)
			{
				
				//VectorSubtract(gApp.polygonstack[i].v[0].p,gPlayer.origin,dir);

				//VectorNormalize(dir);

				if(1)//DotProduct(gCamera.forward,gApp.polygonstack[i].v[0].p)+d>0)

				{
					glBegin(iMode);			
					for(a=0;a<gApp.polygonstack[i].m_iVertices;a++)
					{
						if(iMode!=GL_TRIANGLE_FAN)
							glTexCoord2f(texcoord[a][0],texcoord[a][1]);

						glVertex3f(
							gApp.polygonstack[i].v[a].p[0],//x

						gApp.polygonstack[i].v[a].p[1],//z

						-gApp.polygonstack[i].v[a].p[2]//y

						);
			
					}
				
					glEnd();
				}
			
			}
	}
	}glCullFace(GL_BACK);
	glPushMatrix();
	
	glTranslatef(gPlayer.origin[0],gPlayer.origin[2],gPlayer.origin[1]);
	DrawSky();
	glPopMatrix();glCullFace(GL_FRONT);
http://www.8ung.at/basiror/theironcross.html
JuNC
JuNC
Hmm, this looks like a tricky thing (or maybe I'm just blind). I'd suggest checking all of your math routines and make sure you have all the array indices correct, the thing I'm looking at goes something like this:

I'd guess you declare your player structure like this:

struct Player
{
vec3_t origin;
vec3_t angles;
};

Now, if in some function you are doing

origin[3] += 3; // 3 is just some random example number

Then you will constantly be incrementing angles[0]. Now, I can't see it being done in any of the code there, but you call quite a few functions which operate on the vectors and it's a very easy typo to make.

EDIT:
Aggh! I just spotted you are putting the camera transform in the PROJECTION matrix - BAD! Although this isn't your problem, make sure you rearrange things:


  
glMatrixMode(GL_PROJECTION);	
glLoadIdentity();	
gluPerspective(90.0f,(GLfloat)1280/(GLfloat)1024,32.0f,60000.0f);	
//glRotatef(0.4,0,1,0);	

glRotatef(gPlayer.viewangle[0],1,0,0);	
glRotatef(gPlayer.viewangle[1],0,1,0);	
//glTranslatef(-gPlayer.origin[0],gPlayer.origin[2],-gPlayer.origin[1]);	

glTranslatef(-2000,-256,2000);	
glMatrixMode(GL_MODELVIEW);	
glLoadIdentity();
  



  
glMatrixMode(GL_PROJECTION);	
glLoadIdentity();	
gluPerspective(90.0f,(GLfloat)1280/(GLfloat)1024,32.0f,60000.0f);	
glMatrixMode(GL_MODELVIEW);	
glLoadIdentity();
//glRotatef(0.4,0,1,0);	

glRotatef(gPlayer.viewangle[0],1,0,0);	
glRotatef(gPlayer.viewangle[1],0,1,0);	
//glTranslatef(-gPlayer.origin[0],gPlayer.origin[2],-gPlayer.origin[1]);	

glTranslatef(-2000,-256,2000);


[edited by - JuNC on November 2, 2002 7:43:09 AM]
Basiror
Basiror
hm couldn t find any code mistakes
damn


btw why shouldn t i place my camera transformation into projection matrix thing?
http://www.8ung.at/basiror/theironcross.html
JuNC
JuNC
Well, you''re going to have to do some work narrowing down where the problem is occuring. Start by disabling the code which reads the mouse, if the problem still occurs, work through all the areas where you modify the viewangles or the players origin (it''s definitely modifying the viewangles because the movement is affected). It could be that the GetCursor/SetCursor calls are acting screwy but it''s bizarre why it should only affect the Y axis.

Conventionally you put *only* the screen projection transformation in the PROJECTION matrix. Any other space transforms (ie the camera rotation/translation and object positioning) go into MODELVIEW (hence the name - MODEL VIEW). It still works if you put the camera in the PROJECTION (as you''ve found) but it is not the correct way.
Basiror
Basiror
oh yay now i know why a lot of people don t even bother writing their own engine :D
it s so much easier when carmack writes you one
http://www.8ung.at/basiror/theironcross.html

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