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 [SOLVED] Calculating angle to mouse  (Read 3158 times) 0 Members and 1 Guest are viewing this topic.
DDDBOMBER

Junior Member

Projects: 1

 « Posted 2012-10-30 14:47:01 »

I need help calculating the angle to the mouse from entities,
 1  2  3  4  5  6  7  8  9 `if(orders.get(0) instanceof MoveOrder){              MoveOrder mo = (MoveOrder)orders.get(0);              double xd = mo.x - x;              double yd = mo.y - y;              double rotation = Math.toDegrees(Math.atan2(yd,xd))+270;              rot = rotation;              System.out.println(rot);              orders.remove(0);           }`

This is my current code, but it doesn't seem to work, and the movement code is:
 1  2  3  4  5 `while(rot > 360)rot-= 360;      while(rot < 0)rot+= 360;      double movementAngle = Math.toRadians(rot);        x += Math.sin(movementAngle) * 0.5;        y += Math.cos(movementAngle) * 0.5;`

can anyone help?
deepthought
 « Reply #1 - Posted 2012-10-30 17:19:21 »

everything you have looks correct to me. I assume it's messing up at the stage of getting the angle from the mouse, right? make sure you're getting the right positions in your MoveOrder and entity position.

jocks rule the highschools. GEEKS RULE THE WORLD MWAHAHAHA!!
captain failure test game
h3ckboy

JGO Coder

Medals: 5

 « Reply #2 - Posted 2012-10-30 18:02:44 »

Can you be more specific in "doesn't work"?
kinaite

Junior Member

Projects: 2

 « Reply #3 - Posted 2012-10-30 18:26:20 »

this should help:
angle = Math.toDegrees(Math.atan2(MouseY - entity.y, MouseX - entity.x));
DDDBOMBER

Junior Member

Projects: 1

 « Reply #4 - Posted 2012-10-30 18:29:54 »

It seems to go in completely random directions, and doesn't move to the mouse at all...
kinaite

Junior Member

Projects: 2

 « Reply #5 - Posted 2012-10-30 18:34:31 »

to move: (Worked in my game. see Walking sprites in show case)
deepthought
 « Reply #6 - Posted 2012-10-30 18:43:29 »

you need to find out where you are going wrong. are you getting the correct angle from your first segment?

jocks rule the highschools. GEEKS RULE THE WORLD MWAHAHAHA!!
captain failure test game
DDDBOMBER

Junior Member

Projects: 1

 « Reply #7 - Posted 2012-10-30 20:07:51 »

Okay, i've done some testing, and it seems to work fine x Axis, but messes up somewhere on the y Axis, as in, if i tell it to go from (0,0) to (10,0) it works fine, if i want to move just in the x Axis it has to be
 1  2  3  4 `MoveOrder mo = (MoveOrder)orders.get(0);              double xd = mo.x - x;              double yd = mo.y - y;              double rotation = Math.toDegrees(Math.atan2(yd,xd))+90;`

However, if i want to move in the y Axis it has to be
 1  2  3  4 `MoveOrder mo = (MoveOrder)orders.get(0);              double xd = mo.x - x;              double yd = mo.y - y;              double rotation = Math.toDegrees(Math.atan2(yd,xd))+270;`

Which even further confuses me...

I've got it to move in the right direction by doing it like this
 1  2  3  4  5  6  7  8  9  10  11  12  13  14  15 `double movementAngleX = Math.toRadians(rot);      double movementAngleY = Math.toRadians(rot+180);        x += Math.sin(movementAngleX) * 0.5;        y += Math.cos(movementAngleY) * 0.5;        if(orders.size() > 0){           if(orders.get(0) instanceof MoveOrder){              MoveOrder mo = (MoveOrder)orders.get(0);              double xd = mo.x - x;              double yd = mo.y - y;              double rotation = Math.toDegrees(Math.atan2(yd,xd))+90;              rot = rotation;              System.out.println(rot);              orders.remove(0);           }        }`

But then the rotation on the image is messed up, the rendering code is (im using LWJGL)
 1  2  3  4  5  6  7  8  9 `                GL11.glTranslated(x+32, y+32, 0);        GL11.glRotated(rot, 0, 0, -1);        GL11.glBegin(GL11.GL_QUADS);        GL11.glTexCoord2f(0.0f, 0.0f); GL11.glVertex2f(-32, -32);        GL11.glTexCoord2f(1.0f, 0.0f); GL11.glVertex2f(32, -32);        GL11.glTexCoord2f(1.0f, 1.0f); GL11.glVertex2f(32, 32);        GL11.glTexCoord2f(0.0f, 1.0f); GL11.glVertex2f(-32, 32);         GL11.glEnd();`

Anyone got any ideas?
kinaite

Junior Member

Projects: 2

 « Reply #8 - Posted 2012-10-30 20:29:01 »

this is y coord code:

and try GL11.Rotatef with

angle = angle % 360.0f;
GL11.Rotatef((float)angle...)
DDDBOMBER

Junior Member

Projects: 1

 « Reply #9 - Posted 2012-10-30 20:37:33 »

Thanks! Got it to work,
 1  2  3  4  5  6  7  8  9  10  11  12  13 `double movementAngle = Math.toRadians(rot);        x += Math.sin(movementAngle) * 0.5;        y -= Math.cos(movementAngle) * 0.5;        if(orders.size() > 0){           if(orders.get(0) instanceof MoveOrder){              MoveOrder mo = (MoveOrder)orders.get(0);              double xd = mo.x - x;              double yd = mo.y - y;              double rotation = Math.toDegrees(Math.atan2(yd,xd))+90;              rot = rotation;              orders.remove(0);           }        }`

 1  2 `        float angle = (float) (rot % 360.0f);        GL11.glRotated(angle+180.0f, 0, 0, 1);`
theagentd
 « Reply #10 - Posted 2012-10-31 00:50:39 »

 1  2 `        float angle = (float) (rot % 360.0f);        GL11.glRotated(angle+180.0f, 0, 0, 1);`

glRotate() can handle angles outside 360 degrees, but you should keep the actual stored rotation (rot) to 0-360 degrees.

Myomyomyo.
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