'processing collision test return false at the beginning
I am doing the collision test for the programme, and I tried to insert the test into draw() and I'm expecting it to display "GameOver" and no further events will result any change.
float x;
float y;
float w;
float h;
float xPed;
float yPed;
float yPedc;
float objectX;
float objectY;
float objectWidth;
float objectHeight;
float triangleWidth;
float triangleHeight;
float dia;
int speed = 2;
boolean gameOver;
int N_LANES = 1;
void setup() {
size(1200, 400);
background(255);
x = width / 60;
y = height / 40;
w = width / 80;
xPed = width / 2;
triangleWidth = height / 4;
triangleHeight = 2.5 * w;
yPed = height - 3 * w;
yPedc = 2.5 * w / 2;
dia = w / 2;
h = w / 2;
objectX = x + 2 * w;
objectY = y + 5 * h;
objectWidth = 4 * w;
objectHeight = 10 * h;
gameOver = false;
}
void draw() {
//reset background
background(255);
line(0, height/4, width, height/4);
vehicle();
pedestrian();
// collision detect
if (gameOver == true) {
textSize(100);
fill(255, 0, 0);
text("Game Over", width / 3, height / 2);
}
}
void vehicle() {
//moving vehicle
x += speed;
// reset vehicle
noFill();
if (x > width) {
x = 0;
} else if (x < 0) {
x = width;
}
for (int i = 0; i < N_LANES; i++) {
//head of vehicle
fill(0, 194, 0, 50);
rect(x, y, w, h);
rect(x + 3 * w, y, w, h);
rect(x, y + h, 4 * w, 4 *h);
//eyes of vehicle
fill(0);
rect(x + w, 3 * y, w * 0.85, h);
rect(x + 3 * w, 3 * y, w * 0.85, h);
//body of vehicle
fill(0, 240, 0, 80);
rect(x + 1.5 * w, 6.3 * h, 1.5 * w, 3 *h );
//left arm
line(x + 1.5 *w, 6.3 * h, x + 0.5 * w, 7.3 * h);
//right arm
line(x + 3 * w, 6.3 * h, x + 4 * w, 7.3 * h);
//left leg
line(x + 1.5 * w, 9.3 * h, x + w, 11.3 * h);
//right leg
line(x + 3 * w, 9.3 * h, x + 3.5 * w, 11.3 * h);
}
}
// draw pedestrian
void pedestrian() {
fill(255, 140, 0, 70);
//body of pedestrian
triangle(xPed, yPed, xPed - triangleWidth / 2, yPed + 2.5 * w, xPed + triangleWidth / 2, yPed + 2.5 * w);
fill(0);
circle(xPed + triangleWidth / 4, yPed, dia);
circle(xPed - triangleWidth / 4, yPed, dia);
fill(255, 165, 0);
ellipse(xPed, yPed + w, 1.5 * dia, 3 * dia);
}
// arrow key moving
void keyPressed() {
if (gameOver != true) {
if (key == CODED) {
if (keyCode == UP) {
yPed -= height / 4;
if (yPed <= 0) {
yPed = height - 3 * w;
}
}
if (keyCode == DOWN) {
yPed += height / 4;
if (yPed > height) {
yPed = height - 3 * w;
}
}
if (keyCode==LEFT) {
xPed -= height / 4;
if (xPed < 0 + triangleWidth / 2) {
xPed = width / 2;
}
}
if (keyCode==RIGHT) {
xPed += height / 4;
if (xPed > width - triangleWidth / 2) {
xPed = width / 2;
}
}
}
}
}
boolean gameOver() {
// optional visualise collision objects
rect(objectX, objectY, objectWidth, objectHeight);
rect(xPed, yPed, triangleWidth, triangleHeight);
// x axis
float distX = abs( (objectX + objectWidth / 2) - (xPed + triangleWidth / 2) );
// y axis
float distY = abs( (objectY + objectHeight / 2) - (yPedc + triangleHeight / 2) );
// half combined x distance
float combinedHalfWidth = ( (objectWidth / 2) + (triangleWidth / 2) );
// half combined y distance
float combinedHalfHeight = ( (objectHeight / 2) + (triangleHeight / 2) );
// check collision
if (distX < combinedHalfWidth) {
if (distY < combinedHalfHeight) {
return true;
}
}
return false;
}
I tried to insert the gameOver boolean into draw and it returns the same value everytime.
Just wondering what the logical problem or the coding problem is.
Solution 1:[1]
As Rabbid76 mentions, you should format the code correctly first.
Let's assume the code been copied from a pdf with code snippets and that's how formatting got messed up.
The code still has a few glaring bugs:
- confusingly you're using both a boolean variable
gameOverand a boolean functiongameOver()and the variable isn't always updated. (In factgameOveris only set once insetup()andgameOver()which actually does the collision detection is never called). I recommend either update the boolean variable, or simpler yet, just callgameOver()to compute the collision as needed. This is one of the reasons your code won't behave as you expect. - You're checking collisions between two objects: the vehicle and the pedestrian. However, there are 3 sets of coordinates:
x, y, xPed, objectX, objectY. When rendering in draw, the vehicle usesx,y, however, when checking for collisions,gameOver()usesobjectX, objectY(which don't match and aren't updated). This is the other reason you're collisions don't behave as expected. - aside from the question you've asked,
N_LANESis used in a for loop, but never declared. Even if I declare it, the for loop uses the exact samex,ycoordinates, making the for loop redundant.
Here's a formatted version of your code with extra bounding boxes highlighting what the collision function is checking against (and commenting a few unused variables):
float x;
float y;
float w;
float h;
float xPed;
float yPed;
//float yPedc;
float objectX;
float objectY;
float objectWidth;
float objectHeight;
float triangleWidth;
float triangleHeight;
float dia;
int speed = 2;
//boolean gameOver;
int N_LANES = 1;
void setup() {
size(1200, 400);
background(255);
x = width / 60;
y = height / 40;
w = width / 80;
xPed = width / 2;
triangleWidth = height / 4;
triangleHeight = 2.5 * w;
yPed = height - 3 * w;
//yPedc = 2.5 * w / 2;
dia = w / 2;
h = w / 2;
objectX = x + 2 * w;
objectY = y + 5 * h;
objectWidth = 4 * w;
objectHeight = 10 * h;
//gameOver = false;
}
void draw() {
//reset background
background(255);
line(0, height/4, width, height/4);
vehicle();
pedestrian();
// collision detect
if (gameOver() == true) {
textSize(100);
fill(255, 0, 0);
text("Game Over", width / 3, height / 2);
}
}
void vehicle() {
//moving vehicle
x += speed;
// reset vehicle
noFill();
if (x > width) {
x = 0;
} else if (x < 0) {
x = width;
}
for (int i = 0; i < N_LANES; i++) {
//head of vehicle
fill(0, 194, 0, 50);
rect(x, y, w, h);
rect(x + 3 * w, y, w, h);
rect(x, y + h, 4 * w, 4 *h);
//eyes of vehicle
fill(0);
rect(x + w, 3 * y, w * 0.85, h);
rect(x + 3 * w, 3 * y, w * 0.85, h);
//body of vehicle
fill(0, 240, 0, 80);
rect(x + 1.5 * w, 6.3 * h, 1.5 * w, 3 *h );
//left arm
line(x + 1.5 *w, 6.3 * h, x + 0.5 * w, 7.3 * h);
//right arm
line(x + 3 * w, 6.3 * h, x + 4 * w, 7.3 * h);
//left leg
line(x + 1.5 * w, 9.3 * h, x + w, 11.3 * h);
//right leg
line(x + 3 * w, 9.3 * h, x + 3.5 * w, 11.3 * h);
}
}
// draw pedestrian
void pedestrian() {
fill(255, 140, 0, 70);
//body of pedestrian
triangle(xPed, yPed, xPed - triangleWidth / 2, yPed + 2.5 * w, xPed + triangleWidth / 2, yPed + 2.5 * w);
fill(0);
circle(xPed + triangleWidth / 4, yPed, dia);
circle(xPed - triangleWidth / 4, yPed, dia);
fill(255, 165, 0);
ellipse(xPed, yPed + w, 1.5 * dia, 3 * dia);
// visualise bounding box
//fill(255, 140, 0, 70);
//rect(xPed - triangleWidth / 2, yPed, triangleWidth, triangleHeight);
}
// arrow key moving
void keyPressed() {
if (gameOver() != true) {
if (key == CODED) {
if (keyCode == UP) {
yPed -= height / 4;
if (yPed <= 0) {
yPed = height - 3 * w;
}
}
if (keyCode == DOWN) {
yPed += height / 4;
if (yPed > height) {
yPed = height - 3 * w;
}
}
if (keyCode==LEFT) {
xPed -= height / 4;
if (xPed < 0 + triangleWidth / 2) {
xPed = width / 2;
}
}
if (keyCode==RIGHT) {
xPed += height / 4;
if (xPed > width - triangleWidth / 2) {
xPed = width / 2;
}
}
}
}
}
boolean gameOver() {
// optional visualise collision objects
rect(objectX, objectY, objectWidth, objectHeight);
rect(xPed, yPed, triangleWidth, triangleHeight);
// x axis
float distX = abs( (objectX + objectWidth / 2) - (xPed + triangleWidth / 2) );
// y axis
float distY = abs( (objectY + objectHeight / 2) - (yPed + triangleHeight / 2) );
// half combined x distance
float combinedHalfWidth = ( (objectWidth / 2) + (triangleWidth / 2) );
// half combined y distance
float combinedHalfHeight = ( (objectHeight / 2) + (triangleHeight / 2) );
// check collision
if (distX < combinedHalfWidth) {
if (distY < combinedHalfHeight) {
return true;
}
}
return false;
}
Here's a version of the code with a few of the 3 notes above applied, somewhat resolving the collision and gameOver state issue:
float x;
float y;
float w;
float h;
float xPed;
float yPed;
float objectWidth;
float objectHeight;
float triangleWidth;
float triangleHeight;
float dia;
int speed = 2;
void setup() {
size(1200, 400);
background(255);
x = width / 60;
y = height / 40;
w = width / 80;
xPed = width / 2;
triangleWidth = height / 4;
triangleHeight = 2.5 * w;
yPed = height - 3 * w;
dia = w / 2;
h = w / 2;
objectWidth = 4 * w;
objectHeight = 10 * h;
}
void draw() {
//reset background
background(255);
line(0, height/4, width, height/4);
vehicle();
pedestrian();
// collision detect
if (gameOver()) {
textSize(100);
fill(255, 0, 0);
text("Game Over", width / 3, height / 2);
}
}
void vehicle() {
//moving vehicle
x += speed;
// reset vehicle
noFill();
if (x > width) {
x = 0;
} else if (x < 0) {
x = width;
}
//head of vehicle
fill(0, 194, 0, 50);
rect(x, y, w, h);
rect(x + 3 * w, y, w, h);
rect(x, y + h, 4 * w, 4 *h);
//eyes of vehicle
fill(0);
rect(x + w, 3 * y, w * 0.85, h);
rect(x + 3 * w, 3 * y, w * 0.85, h);
//body of vehicle
fill(0, 240, 0, 80);
rect(x + 1.5 * w, 6.3 * h, 1.5 * w, 3 *h );
//left arm
line(x + 1.5 *w, 6.3 * h, x + 0.5 * w, 7.3 * h);
//right arm
line(x + 3 * w, 6.3 * h, x + 4 * w, 7.3 * h);
//left leg
line(x + 1.5 * w, 9.3 * h, x + w, 11.3 * h);
//right leg
line(x + 3 * w, 9.3 * h, x + 3.5 * w, 11.3 * h);
}
// draw pedestrian
void pedestrian() {
fill(255, 140, 0, 70);
//body of pedestrian
triangle(xPed, yPed, xPed - triangleWidth / 2, yPed + 2.5 * w, xPed + triangleWidth / 2, yPed + 2.5 * w);
fill(0);
circle(xPed + triangleWidth / 4, yPed, dia);
circle(xPed - triangleWidth / 4, yPed, dia);
fill(255, 165, 0);
ellipse(xPed, yPed + w, 1.5 * dia, 3 * dia);
// visualise bounding box
//fill(255, 140, 0, 70);
//rect(xPed - triangleWidth / 2, yPed, triangleWidth, triangleHeight);
}
// arrow key moving
void keyPressed() {
if (!gameOver()) {
if (key == CODED) {
if (keyCode == UP) {
yPed -= height / 4;
if (yPed <= 0) {
yPed = height - 3 * w;
}
}
if (keyCode == DOWN) {
yPed += height / 4;
if (yPed > height) {
yPed = height - 3 * w;
}
}
if (keyCode==LEFT) {
xPed -= height / 4;
if (xPed < 0 + triangleWidth / 2) {
xPed = width / 2;
}
}
if (keyCode==RIGHT) {
xPed += height / 4;
if (xPed > width - triangleWidth / 2) {
xPed = width / 2;
}
}
}
}
}
boolean gameOver() {
// optional visualise collision objects
rect(x, y, objectWidth, objectHeight);
rect(xPed, yPed, triangleWidth, triangleHeight);
// x axis
float distX = abs( (x + objectWidth / 2) - (xPed + triangleWidth / 2) );
// y axis
float distY = abs( (y + objectHeight / 2) - (yPed + triangleHeight / 2) );
// half combined x distance
float combinedHalfWidth = ( (objectWidth / 2) + (triangleWidth / 2) );
// half combined y distance
float combinedHalfHeight = ( (objectHeight / 2) + (triangleHeight / 2) );
// check collision
if (distX < combinedHalfWidth) {
if (distY < combinedHalfHeight) {
return true;
}
}
return false;
}
Notice that the triangle bounding box needs to be moved to the left by half the triangle width ideally.
I'd also like to point you to java.awt.Rectangle which has an intersects() that could be useful:
import java.awt.Rectangle;
float x;
float y;
float w;
float h;
float xPed;
float yPed;
float objectWidth;
float objectHeight;
float triangleWidth;
float triangleHeight;
float dia;
int speed = 2;
Rectangle vehicleBoundingBox;
Rectangle pedestrianBoundingBox;
void setup() {
size(1200, 400);
background(255);
x = width / 60;
y = height / 40;
w = width / 80;
xPed = width / 2;
triangleWidth = height / 4;
triangleHeight = 2.5 * w;
yPed = height - 3 * w;
dia = w / 2;
h = w / 2;
objectWidth = 4 * w;
objectHeight = 10 * h;
vehicleBoundingBox = new Rectangle((int)x, (int)y, (int)objectWidth, (int)objectHeight);
pedestrianBoundingBox = new Rectangle((int)xPed, (int)yPed, (int)triangleWidth, (int)triangleHeight);
}
void draw() {
//reset background
background(255);
line(0, height/4, width, height/4);
vehicle();
pedestrian();
// collision detect
if (gameOver()) {
textSize(100);
fill(255, 0, 0);
text("Game Over", width / 3, height / 2);
}
}
void vehicle() {
//moving vehicle
x += speed;
// reset vehicle
noFill();
if (x > width) {
x = 0;
} else if (x < 0) {
x = width;
}
//head of vehicle
fill(0, 194, 0, 50);
rect(x, y, w, h);
rect(x + 3 * w, y, w, h);
rect(x, y + h, 4 * w, 4 *h);
//eyes of vehicle
fill(0);
rect(x + w, 3 * y, w * 0.85, h);
rect(x + 3 * w, 3 * y, w * 0.85, h);
//body of vehicle
fill(0, 240, 0, 80);
rect(x + 1.5 * w, 6.3 * h, 1.5 * w, 3 *h );
//left arm
line(x + 1.5 *w, 6.3 * h, x + 0.5 * w, 7.3 * h);
//right arm
line(x + 3 * w, 6.3 * h, x + 4 * w, 7.3 * h);
//left leg
line(x + 1.5 * w, 9.3 * h, x + w, 11.3 * h);
//right leg
line(x + 3 * w, 9.3 * h, x + 3.5 * w, 11.3 * h);
}
// draw pedestrian
void pedestrian() {
fill(255, 140, 0, 70);
//body of pedestrian
triangle(xPed, yPed, xPed - triangleWidth / 2, yPed + 2.5 * w, xPed + triangleWidth / 2, yPed + 2.5 * w);
fill(0);
circle(xPed + triangleWidth / 4, yPed, dia);
circle(xPed - triangleWidth / 4, yPed, dia);
fill(255, 165, 0);
ellipse(xPed, yPed + w, 1.5 * dia, 3 * dia);
}
// arrow key moving
void keyPressed() {
if (!gameOver()) {
if (key == CODED) {
if (keyCode == UP) {
yPed -= height / 4;
if (yPed <= 0) {
yPed = height - 3 * w;
}
}
if (keyCode == DOWN) {
yPed += height / 4;
if (yPed > height) {
yPed = height - 3 * w;
}
}
if (keyCode==LEFT) {
xPed -= height / 4;
if (xPed < 0 + triangleWidth / 2) {
xPed = width / 2;
}
}
if (keyCode==RIGHT) {
xPed += height / 4;
if (xPed > width - triangleWidth / 2) {
xPed = width / 2;
}
}
}
}
}
boolean gameOver(){
// update bounding box positions
vehicleBoundingBox.x = (int)x;
vehicleBoundingBox.y = (int)y;
pedestrianBoundingBox.x = (int)(xPed - triangleWidth / 2);
pedestrianBoundingBox.y = (int)yPed;
//optional: visualise boxes
fill(255, 140, 0, 70);
rect(pedestrianBoundingBox.x, pedestrianBoundingBox.y, pedestrianBoundingBox.width, pedestrianBoundingBox.height);
rect(vehicleBoundingBox.x, vehicleBoundingBox.y, vehicleBoundingBox.width, vehicleBoundingBox.height);
return vehicleBoundingBox.intersects(pedestrianBoundingBox);
}
//boolean gameOver() {
// // optional visualise collision objects
// rect(x, y, objectWidth, objectHeight);
// rect(xPed, yPed, triangleWidth, triangleHeight);
// // x axis
// float distX = abs( (x + objectWidth / 2) - (xPed + triangleWidth / 2) );
// // y axis
// float distY = abs( (y + objectHeight / 2) - (yPed + triangleHeight / 2) );
// // half combined x distance
// float combinedHalfWidth = ( (objectWidth / 2) + (triangleWidth / 2) );
// // half combined y distance
// float combinedHalfHeight = ( (objectHeight / 2) + (triangleHeight / 2) );
// // check collision
// if (distX < combinedHalfWidth) {
// if (distY < combinedHalfHeight) {
// return true;
// }
// }
// return false;
//}
void circle(float x, float y, float dia){
ellipse(x, y, dia, dia);
}
Bare in mind, if this is an assignment/homework, you might not be allowed to use java.awt.Rectangle. Speaking of which, if this is an assignment you should mention that in the question.
Update
Here's an updated version better handling the game over state.
float x;
float y;
float w;
float h;
float xPed;
float yPed;
float objectWidth;
float objectHeight;
float triangleWidth;
float triangleHeight;
float dia;
int speed = 2;
// defaults to false
boolean isGameOver;
void setup() {
size(1200, 400);
background(255);
x = width / 60;
y = height / 40;
w = width / 80;
xPed = width / 2;
triangleWidth = height / 4;
triangleHeight = 2.5 * w;
yPed = height - 3 * w;
dia = w / 2;
h = w / 2;
objectWidth = 4 * w;
objectHeight = 10 * h;
}
void draw() {
//reset background
background(255);
line(0, height/4, width, height/4);
if (isGameOver) {
textSize(100);
fill(255, 0, 0);
text("Game Over", width / 3, height / 2);
}else{
// check colloisions only in game state and update game over state
isGameOver = checkCollisions();
vehicle();
pedestrian();
}
}
void vehicle() {
//moving vehicle
x += speed;
// reset vehicle
noFill();
if (x > width) {
x = 0;
} else if (x < 0) {
x = width;
}
//head of vehicle
fill(0, 194, 0, 50);
rect(x, y, w, h);
rect(x + 3 * w, y, w, h);
rect(x, y + h, 4 * w, 4 *h);
//eyes of vehicle
fill(0);
rect(x + w, 3 * y, w * 0.85, h);
rect(x + 3 * w, 3 * y, w * 0.85, h);
//body of vehicle
fill(0, 240, 0, 80);
rect(x + 1.5 * w, 6.3 * h, 1.5 * w, 3 *h );
//left arm
line(x + 1.5 *w, 6.3 * h, x + 0.5 * w, 7.3 * h);
//right arm
line(x + 3 * w, 6.3 * h, x + 4 * w, 7.3 * h);
//left leg
line(x + 1.5 * w, 9.3 * h, x + w, 11.3 * h);
//right leg
line(x + 3 * w, 9.3 * h, x + 3.5 * w, 11.3 * h);
}
// draw pedestrian
void pedestrian() {
fill(255, 140, 0, 70);
//body of pedestrian
triangle(xPed, yPed, xPed - triangleWidth / 2, yPed + 2.5 * w, xPed + triangleWidth / 2, yPed + 2.5 * w);
fill(0);
circle(xPed + triangleWidth / 4, yPed, dia);
circle(xPed - triangleWidth / 4, yPed, dia);
fill(255, 165, 0);
ellipse(xPed, yPed + w, 1.5 * dia, 3 * dia);
// visualise bounding box
//fill(255, 140, 0, 70);
//rect(xPed - triangleWidth / 2, yPed, triangleWidth, triangleHeight);
}
// arrow key moving
void keyPressed() {
if (isGameOver){
// exit game over
isGameOver = false;
// lazy way to restart the game
// normally you'd write & call a reset() function to reset player/vehicle positions, avodiing instant gameOver
setup();
} else {
if (key == CODED) {
if (keyCode == UP) {
yPed -= height / 4;
if (yPed <= 0) {
yPed = height - 3 * w;
}
}
if (keyCode == DOWN) {
yPed += height / 4;
if (yPed > height) {
yPed = height - 3 * w;
}
}
if (keyCode==LEFT) {
xPed -= height / 4;
if (xPed < 0 + triangleWidth / 2) {
xPed = width / 2;
}
}
if (keyCode==RIGHT) {
xPed += height / 4;
if (xPed > width - triangleWidth / 2) {
xPed = width / 2;
}
}
}
}
}
boolean checkCollisions() {
// optional visualise collision objects
fill(255, 140, 0, 70);
rect(x, y, objectWidth, objectHeight);
rect(xPed - triangleWidth / 2, yPed, triangleWidth, triangleHeight);
// x axis
float distX = abs( (x + objectWidth / 2) - xPed );
// y axis
float distY = abs( (y + objectHeight / 2) - (yPed + triangleHeight / 2) );
// half combined x distance
float combinedHalfWidth = ( (objectWidth / 2) + (triangleWidth / 2) );
// half combined y distance
float combinedHalfHeight = ( (objectHeight / 2) + (triangleHeight / 2) );
// check collision
if (distX < combinedHalfWidth) {
if (distY < combinedHalfHeight) {
return true;
}
}
return false;
}
The main changes are:
- reintroduced
gameOverboolean asisGameOverwhich is used to change between the two states - renamed
gameOver()tocheckCollisions()to avoid confusion.
In this case, with just two states, a boolean will do. It's important to also reset game variables when changing state (e.g. reset player/vehicle positions, etc.) In case your game may require more states you can use an integer and constants. This answer has a demo code snippet. If multiple states are required OOP was introduced, this answer also has demo code.
Sources
This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.
Source: Stack Overflow
| Solution | Source |
|---|---|
| Solution 1 |