Hi all I am in need of some help. I am working on a project and would like my enemy sprite to move back end forth for a specific distance. I have manged to get him to flip from right to left, then after that he disappears. I am sure there is something wrong with my conditional statement (or maybe I may need a loop) please help.
if(enemystart <= 0 && enemystart >= -100)
{
enemystart = enemystart + (enemyspeed * enemydirection * -1);
image(zombieL[frameCount % 10], enemystart, floorPos_y - 58, 60, 60);
}
else if(enemyp1 >= -100 && enemyp1 <= 0)
{
enemyp1 = enemyp1 + (enemyspeed * enemydirection);
image(zombie[frameCount % 10], enemyp1, floorPos_y - 58, 60, 60);
}
I think you didn't change the enemydirection variable. Change it to 90 on turning right and -90 on turning left. And also 0 on turning towards top and 180 on turning bottom. This might solve the problem? I guess so!
Related
This is a code example from book:
width, height = 240, 60
midx, midy = width // 2, height // 2
for xen in range(width):
for уen in range(height):
if xen < 5 or xen >= width - 5 or уen < 5 or уen >= height - 5:
image[xen, yen] = border_color
elif midx - 20 < xen < midx + 20 and midy - 20 < уen < midy + 20:
image[xen, yen] = square_color
When I try to run this, I get error: 'yen' is not defined. But it was defined in 'for' loop, and so 'xen' was defined. I know that the book I am reading is kind of old, but I don't understand why am I getting this error and how to avoid this. I know there are loops, but this code seems fully legit to me. What's the trick?
When I copy and paste your code, the y in yen in your for loop is an odd character (maybe a Cyrillic 'U'). It looks like a y but it's not. Try retyping the line:
for уen in range(height):
These look the same, but if you run the snippet, you'll see they aren't:
console.log("уen" == "yen")
Hello I am trying to limit how much a user can drag within Gamemaker.
I have created two views within a room.
The first view is the full room width and size 1250x768
The second view is the area which i would like the user to be able to zoom into and drag which is 955x465. x and y position is 40 by 170.
Currently i have set up the zoom for the second view which is:
vmx=(mouse_x-X)-omx;
omx=(mouse_x-X);
vmy=(mouse_y-Y)-omy;
omy=(mouse_y-Y);
if mouse_wheel_up() && view_wview[1] > 600 {
center_of_space_x=view_xview[1]+view_wview[1]/2;
center_of_space_y=view_yview[1]+view_hview[1]/2;
view_wview[1]-=view_wview[1]*0.15;
view_hview[1]-=view_hview[1]*0.15;
view_xview[1]=center_of_space_x-view_wview[1]/2;
view_yview[1]=center_of_space_y-view_hview[1]/2;
}
if mouse_wheel_down(){
view_xview[1] = 40;
view_yview[1] = 170;
view_wview[1] = 955;
view_hview[1] = 465;}
Below is the code for the drag:
if (mouse_check_button_pressed(mb_left)) {
drag_x = mouse_x
drag_y = mouse_y
}
// update:
if (mouse_check_button(mb_left)) && view_wview[1] < 700 {
// actual dragging logic:
view_xview[1] = drag_x - (mouse_x - view_xview[1])
view_yview[1] = drag_y - (mouse_y - view_yview[1])
// make sure view doesn't go outside the room:
view_xview[1] = max(0, min(view_xview[1], room_width - view_wport[1]))
view_yview[1] = max(0, min(view_yview[1], room_height - view_hview[1]))
So the limit works for the view to not leave the room but i want it not to leave the specific view which has been set up.
Please help
I have modified my code to use a clamp function which works but it is not a clean solution:
view_xview[1] = clamp(view_xview[1],40,400);
view_yview[1] = clamp(view_yview[1],170,500);
The user has to be fully zoomed in to have the view restricted. If he is not then they can still see other areas of the room :(
EDIT: I may have misunderstood your question, I will leave the below code for reference if it helps you solve the problem a bit differently.
I would probably check that mouse_x and mouse_y are not outside the view you want.
if (mouse_x > view_limit_x || mouse_y > view_limit_y)
{
return; // Or continue or break however your language of choice goes.
}
If you cannot do a return statement, wrapping your code in a reverse logic of above should work fine.
Old Post:
I am not 100% familiar with game maker. I would implement something like this by skipping the drag logic every x frames. Say you are updating at 60fps, and you want the drag to be 6 times slower, you just need to only update the logic 10 x per frame.
const int framesToSkip = 6;
int frameCount = 0;
update()
{
// Will only call when framecount = 0, 6, 12, 18 etc.
if (frameCount % framesToSkip == 0)
{
// Drag Logic.
}
frameCount++;
}
This way drag logic only occurs 1/6 the rate as before. You could also change this around to happen the first x amount of frames and then skip for the rest (but this may appear a bit choppy).
I am learning game programming with Phaser and I am currently building a simple breakout game.
When the ball hits the paddle I use the following code to determine the new x velocity of the ball:
if (ball.x < paddle.x)
{
// Ball is on the left-hand side of the paddle
diff = paddle.x - ball.x;
ball.body.velocity.x = (-10 * diff);
}
else if (ball.x > paddle.x)
{
// Ball is on the right-hand side of the paddle
diff = ball.x -paddle.x;
ball.body.velocity.x = (10 * diff);
}
else
{
// Ball is perfectly in the middle
// Add a little random X to stop it bouncing straight up!
ball.body.velocity.x = 2 + Math.random() * 8;
}
This code is originally taken I believe from stackoverflow, although I cannot remember from which post I'm afraid.
The problem with this is that when the ball goes left or right at an angle, it appears faster on screen than if it goes straight up. The more pronounced the angle, the faster it goes and appears.
Does anyone know how to solve this problem?
Regards
Crouz
The speed of the ball is given by a combination of the horizontal (x) speed and vertical (y) speed, as given by Pythagoras' theorem:
z2 = x2 + y2
where overall speed would be z.
If you increase x without decreasing y appropriately, then the overall speed will also increase.
If you want the speed to remain the same, then you need to adjust y as well. Example pseudo-code:
speed = sqrt(x^2 + y^2)
x = 2 + random()*8
y = sqrt(speed^2 - x^2)
You could incorporate this into your code by calculating speed before any adjustments are made, and then adjusting y afterwards:
// Calculate overall speed
var speed = Math.sqrt(
Math.pow(ball.body.velocity.x, 2) +
Math.pow(ball.body.velocity.y, 2)
);
if (ball.x < paddle.x)
{
// Ball is on the left-hand side of the paddle
diff = paddle.x - ball.x;
ball.body.velocity.x = (-10 * diff);
}
else if (ball.x > paddle.x)
{
// Ball is on the right-hand side of the paddle
diff = ball.x -paddle.x;
ball.body.velocity.x = (10 * diff);
}
else
{
// Ball is perfectly in the middle
// Add a little random X to stop it bouncing straight up!
ball.body.velocity.x = 2 + Math.random() * 8;
}
// Adjust y to maintain same overall speed
ball.body.velocity.y = Math.sqrt(
Math.pow(speed, 2) -
Math.pow(ball.body.velocity.x, 2)
);
This will always result in a positive y, so you might need to negate it depending on which direction (up or down) you want it to be moving.
I'm new to graphics and was wondering how I would go about creating an object boundary for my game.
Right now I have an object following my mouse. This works fine for my boundary when my ship has a rotation.z of 0. However, when I rotate the ship, the boundary has odd behavior.
I tried getting the world position of the ship and simply checking the x and y boundaries. However, the world position seems to give me a different x and y when I rotate. How can I
go about creating a boundary that works for all the rotations of my ship.
Here's my game(collisions turned off for purpose of help): http://www.cis.gvsu.edu/~chaua/CS371/WebGLProject/home.html
The behavior I'd like occurs when you don't rotate the ship.
Rotate the ship with left/right mouse.
Relevant code snippets(in render loop):
if(mouseLeftDown)
ship.rotation.z += leanSpeed;
if(mouseRightDown)
ship.rotation.z += -leanSpeed;
....
....
targetX = ((lastMouseX / window.innerWidth) * 2 - 1) * 90;
targetY = -((lastMouseY / window.innerHeight) * 2 - 1) * 60;
var worldPosition = (new THREE.Vector3()).getPositionFromMatrix(ship.matrixWorld);
if(worldPosition.x + targetX <= (randSpawnWidth/2)-500 && worldPosition.x + targetX >= -(randSpawnWidth/2)+500)
ship.translateX(targetX);
if(worldPosition.y + targetY <= (randSpawnHeight/2)-500 && worldPosition.y + targetY >= -(randSpawnHeight/2)+500)
ship.translateY(targetY);
I would appreciate any help. Thanks!
Using VC++ and Open CV. Here's what I'm trying to do:
find the first three nearly-horizontal hough lines and draw them.
find all the nearly-vertical lines and draw them
if any vertical line is above the horizontal line then a FLAG is set to 0
if there is no vertical Hough line above (all are below) the horizontal line then FLAG=1
int n, i,c=0;
int flag = 0;
cvCanny( src, dst, 50, 150, 3 );
lines = cvHoughLines2( dst, storage, CV_HOUGH_PROBABILISTIC, 1, CV_PI/180, 10, 5, 5 );
n = lines->total;
for( i = 0; i < n; i++ )
{
CvPoint* line = (CvPoint*)cvGetSeqElem(lines,i);
CvPoint pt1, pt2, hpt1, hpt2, vpt1, vpt2;
int hy = 0, vy = 0;
pt1 = line[0];
pt2 = line[1];
theta = atan( (double)(pt2.y - pt1.y)/(pt2.x - pt1.x) ); /*slope of line*/
degree = theta*180/CV_PI;
if( fabs(degree) < 8) //checking for near horizontal line
{
c++;
if( c > 0 && c <5) /*main horizontal lines come first*/
{
cvLine( out, pt1, pt2, CV_RGB(255, 255,255), 1, CV_AA, 0 );
hpt1 = line[0];
hpt2 = line[1];
if( hpt1.y > hpt2.y ) //finds out lower end-point
hy = hpt1.y;
else
hy = hpt2.y;
}
}
if( fabs(degree) > 70 ) /*near vertical lines*/
{
cvLine( out, pt1, pt2, CV_RGB(255, 255,255), 1, CV_AA, 0 );
vpt1 = line[0];
vpt2 = line[1];
if( vpt1.y > vpt2.y ) //finds upper end-pt of vertical line
vy = vpt1.y;
else
vy = vpt2.y;
if( vy >= hy ) //if vert line is lower than horizontal line
flag = 1;
else
flag = 0;
}
}
display( out, "hough lines" );
return flag;
}
However for an image even if vertical lines are detected above the horizontal line -still the flag is returning 1. So am i counting along the axis wrongly? Please help me out.
The if( fabs(degree) > 70 ) and if( fabs(degree) < 8 ) lines look wrong. An angle of about 180 means almost horizontal ... you probably want to change that, and bear in mind the periodicity of angles (so about 360 is also almost horizontal). A way to nicely handle that would be to use if (fabs(cos(angle - desired_angle)) > 0.996), which means roughly "if angle and desired_angle are within 5 degrees of each other, disregarding direction". 0.996 is roughly the cosine of 5 degrees, if you need it more exact put more digits there - 0.9961946980917455 is a nearer match.
Also, your loop order is off. You don't find the first three nearly-horizontal hough lines and draw them. find all the nearly-vertical lines and draw them if any vertical line is above the horizontal line in this sequence, you loop over all lines, in any order, and process them independently - the vertical ones could come before the horizontal ones, so you wouldn't know what to check for.
Third,
if( hpt1.y > hpt2.y ) //finds out lower end-point
hy = hpt1.y;
else
hy = hpt2.y;
vs
if( vpt1.y > vpt2.y ) //finds upper end-pt of vertical line
vy = vpt1.y;
else
vy = vpt2.y;
You use the same code to find the lower coordinate as to find the higher one. Do you think that could work?
Fourth,
if( vy >= hy ) //if vert line is lower than horizontal line
flag = 1;
else
flag = 0;
The value of flag depends on the LAST pass through this piece of code. This doesn't match the any in your description.
A much easier approche is to not use the PPHL (progressive probabilistic Hough Lines algorithm) but the SHL (standard HL) ! So that you get the polar form of a line with angle and radius ! You can then just check the angle, without calculating it yourself.
If the output angle is around 0° or 180° it's a vertical line, and if it's around 90° it's a horizontal line....