I'm trying to fabricate a smoothscrolling function which makes a rectangle move up and down the screen to the desired option in a smooth manner.
For this effect I use the following function, which is called in a loop:
float scrollBarPos;
void Menu::smoothScroller() {
float toPos;
if (optionCount > maxOptions) {
if (currentOption > maxOptions) {
toPos = ((maxOptions * 0.035f) + 0.1765f);
} else {
toPos = ((currentOption * 0.035f) + 0.1765f);
}
} else {
toPos = ((currentOption * 0.035f) + 0.1765f);
}
if (scrollBarPos > toPos) {
scrollBarPos -= 0.0005f;
}
if (scrollBarPos < toPos) {
scrollBarPos += 0.0005f;
}
}
Now to draw the rectangle, I use:
GRAPHICS::DRAW_SPRITE("commonmenu", "gradient_nav", pos, scrollBarPos, 0.23f, 0.035f, 0, 255, 255, 255, 255);
Where scrollBarPos is the float of the smoothScroller function.
The problem: scrollBarPos either increases or decreases with 0.0005f. That's very slow, but the rectangle is drawn correctly on screen. When changing it to 0.0200f, it scrolls at a great speed but somehow goes out of place.
What could be the problem here?
Change:
if (scrollBarPos > toPos) {
scrollBarPos -= 0.0005f;
}
if (scrollBarPos < toPos) {
scrollBarPos += 0.0005f;
}
to:
if (std::fabs(scrollBarPos - toPos) < 0.0200f) {
scrollBarPos = toPos;
} else {
if (scrollBarPos > toPos) {
scrollBarPos -= 0.0200f;
} else if (scrollBarPos < toPos) {
scrollBarPos += 0.0200f;
}
}
Related
I was making a super-mario-like game in C++/SFML and while trying to write some code for Mario collisions, I had some problems: The character, when collides with a vertical stack of blocks while moving along the horizontal axis, get stuck on one side of the blocks, like if it is walking on an invisible block. I tried to modify the collision function like making mario to collide with blocks horizontally only if his position related to blocks is contained into the block coordinates.
I include some code for the movement(keyPressed is a function that returns the key pressed):
void Player::movement(Time& gameTime) {
player.move(v * gameTime.asSeconds());
view.setCenter(player.getPosition().x + 16, 590);
if (keyPressed(up) && !jumping) {
jumping = true;
v.y = jumpSpeed;
}
if (v.y > 200) {
jumping = true;
}
else {
crouch = false;
}
if (keyPressed(left)) {
if (v.x > -moveSpeed) {
v.x -= 100;
}
else {
v.x = -moveSpeed;
}
}
else if (keyPressed(right)) {
noKeyPressed = false;
if (v.x < moveSpeed) {
v.x += 100;
}
else {
v.x = moveSpeed;
}
}
else {
if (v.x < -100) {
v.x += 100;
}
else if (v.x > 100) {
v.x -= 100;
}
else {
v.x = 0;
}
}
gravity();
if (big) { //Big is a variable that tells me if mario is big or small
heightValue = 33; //heightValue is a variable that stores the sprite height in pixels
}
else {
heightValue = 16;
}
}
void Player::gravity() {
if (!big) {
if (player.getPosition().y + 32 < 1100) {
if (v.y < maxSpeed) {
v.y += 100;
}
}
if (alive) { //This is useful to check if big mario has fallen
if (player.getPosition().y + 32 >= 1200) {
player.setPosition(player.getPosition().x, 1200 - 32);
jumping = false;
alive = false;
}
}
}
else {
if (player.getPosition().y + 64 < 1100) {
if (v.y < maxSpeed) {
v.y += 100;
}
}
if (alive) { //This is useful to check if small mario has fallen
if (player.getPosition().y + 64 >= 1200) {
player.setPosition(player.getPosition().x, 1200 - 64);
jumping = false;
alive = false;
}
}
}
}
And the collision function, where the block class has 4 small blocks around the block sprite that simplify collisions:
void Player::collisions(Block* block) {
if (this->player.getGlobalBounds().intersects(block->up.getGlobalBounds())) {
if (!big) {
if (this->player.getPosition().y + heightValue <= block->block.getPosition().y) {
this->player.setPosition(this->player.getPosition().x, block->up.getPosition().y - 32);
v.y = 0;
jumping = false;
score = 100;
}
}
else {
if (this->player.getPosition().y + heightValue <= block->block.getPosition().y) {
this->player.setPosition(this->player.getPosition().x, block->up.getPosition().y - 64);
v.y = 0;
jumping = false;
score = 100;
}
}
}
if (this->player.getGlobalBounds().intersects(block->down.getGlobalBounds())) {
this->player.setPosition(this->player.getPosition().x, block->down.getPosition().y + 1);
v.y = 0;
}
if (this->player.getGlobalBounds().intersects(block->left.getGlobalBounds()) && v.x > 0) {
this->player.setPosition(block->left.getPosition().x - 32, this->player.getPosition().y);
}
else if (this->player.getGlobalBounds().intersects(block->right.getGlobalBounds()) && v.x < 0) {
this->player.setPosition(block->right.getPosition().x + 1, this->player.getPosition().y);
}
}
I hope I explained accurately the problem.
simply do your collision detection one axis at a time, this allows nice smooth movement along tiles
pseudocode example:
//X axis
oldPos = position
if(leftKey):
position.x -= speed
if(rightKey):
position.x += speed
if(collision):
position = oldPos
//Y axis
oldPos = position
if(upKey):
position.y -= speed
if(downKey):
position.y += speed
if(collision):
position = oldPos
This is my first attempt with SFML and game development, and I'm having issues with the collision and gravity.
I'm making a 2D platformer game using a tilemap system.
Collision seems to be working(slightly) but is very choppy and I just can't seem to get gravity to work properly. I've tried a few different tutorials but I cant get anything working and I'm at a bit of a loss right now.
If someone could point out what I'm missing here it'd be greatly appreciated!!
Heres the code I'm using for these elements:
In PlayerSprite class(attempt at gravity)
PlayerSprite::PlayerSprite(const sf::Vector2f& size) : AnimatedSprite(size)
{
playerPos = (sf::Vector2f(300.0f, 400.0f));
dead = false;
jumpHeight = 5.f;
scale = 50.f;
accelGravity = 0.5f;
maxGravity = 5.f;
velocity.x = 2.0f;
velocity.y = 2.0f;
playerTexture.loadFromFile("gfx/spritemansheet.png");
setSize(sf::Vector2f(48, 48));
setPosition(playerPos);
setTexture(&playerTexture);
}
PlayerSprite::~PlayerSprite()
{
}
void PlayerSprite::update(float dt)
{
onGround = false;
if (input->isKeyDown(sf::Keyboard::A)) {
input->setKeyUp(sf::Keyboard::A);
playerPos.x -= (dt * step) * 5;
setPosition(playerPos);
//currentAnimation = &walkBack;
}
if (input->isKeyDown(sf::Keyboard::D)) {
input->setKeyUp(sf::Keyboard::D);
playerPos.x += (dt * step) * 5;
setPosition(playerPos);
//currentAnimation = &walk;
}
if (input->isKeyDown(sf::Keyboard::W) ) {
input->setKeyUp(sf::Keyboard::Space);
playerPos.x += (dt * step) * 5;
setPosition(playerPos);
//currentAnimation = &jump;
velocity.y = -5.f * -1;
}
if (onGround == false) {
velocity.y += accelGravity;
if (velocity.y > maxGravity) {
velocity.y = maxGravity;
}
}
if (sf::Mouse::isButtonPressed(sf::Mouse::Left))
{
input->setMouseLeftUp(sf::Mouse::Left);
currentAnimation = &attack;
}
}
void PlayerSprite::setInput(Input* newInp)
{
input = newInp;
}
void PlayerSprite::collisionResponse(Sprite* sp)
{
if (velocity.x > 0) {
velocity.x = 0.f;
}
if (velocity.x < 0) {
velocity.x = 0.f;
}
if (velocity.y > 0) {
velocity.y = 0.f;
onGround = true;
}
if (velocity.y < 0) {
velocity.y = 0.f;
}
setPosition(getPosition().x, sp->getPosition().y - getSize().y);
}
Collision Detection in Game.cpp
void Game::update(float dt)
{
player.update(dt);
manager.update(dt);
std::vector<Tile>* world = worldMap.getScene();
for (int i = 0; i < (int)world->size(); i++) {
if ((*world)[i].isAlive()) {
if (checkGroundBounding(&player, &(*world)[i])) {
player.collisionResponse(&(*world)[i]);
}
}
}
void Game::render() {
beginDraw();
window->draw(bg);
window->draw(player);
manager.render(window);
worldMap.render(window);
endDraw();
}
bool Game::checkGroundBounding(PlayerSprite* b1, Tile* b2)
{
//get radius of sprites
float r1 = b1->getSize().x / 2;
float r2 = b2->getSize().x / 2;
float xposb1 = b1->getPosition().x + r1;
float xposb2 = b2->getPosition().x + r2;
float yposb1 = b1->getPosition().y + r1;
float yposb2 = b2->getPosition().y + r2;
if (pow(xposb2 - xposb1, 2) + pow(yposb2 - yposb1, 2) < pow(r1 + r2, 2)) {
return true;
}
return false;
}
you're collision is super wonky, simply set a oldPos variable to your player position, then do your movement code but only for the X axis, if collision is detected, set the position to oldPos, then set oldPos to the current position again, and repeat for the Y axis:
Pseudocode example:
//X axis
oldPos = position
if(leftKey):
position.x -= speed
if(rightKey):
position.x += speed
if(collision):
position = oldPos
//Y axis
oldPos = position
if(upKey):
position.y -= speed
if(downKey):
position.y += speed
if(collision):
position = oldPos
also you can replace your tile iteration with:
for(Tile t : *world){
t->doStuff();
}
I also don't recommend declaring your tile vector in your update function unless you hate performance
I'm trying to make a game (simple 2d platformer).
The program runs as it should, but an if statement doesn't work correctly.
I have this function:
int Collision::platformCollision(SDL_Rect *hitbox, SDL_Rect plat) {
if (checkCollision(*hitbox, plat)) {
//X
//LEFT SIDE
if (hitbox->x + hitbox->w > plat.x && hitbox->x + hitbox->w < plat.x + 5) {
hitbox->x = plat.x - hitbox->w;
return 1;
}
//RIGHT SIDE
if (hitbox->x < plat.x + plat.w && hitbox->x > plat.x + plat.w - 5) {
hitbox->x = plat.x + plat.w;
return 2;
}
//Y
//UPPER SIDE
if (hitbox->y + hitbox->h > plat.y && hitbox->y + hitbox->h < plat.y + 10) {
hitbox->y = plat.y - hitbox->h;
return 3;
}
//BOTTOM SIDE
if (hitbox->y < plat.y + plat.h && hitbox->y > plat.y + plat.h - 10) {
hitbox->y = plat.y + plat.h;
return 4;
}
}
//NOT COLLIDING
return -1;
}
So I have this function return an int whenever it collides with a certain part of the platform.
Then I have this function:
void Player::playerCheckPlatCollision(SDL_Rect rect) {
if (platformCollision(p_hitboxPTR, rect) == 3) {
setGravityF(0.0);
}
if (platformCollision(p_hitboxPTR, rect) == 4) {
p_space = false;
}
return;
}
The problem should be easy to fix.
When I debug the program it gets to return 4; in the platformCollision function, but when I do
if (platformCollision(p_hitboxPTR, rect) == 4) {
p_space = false;
}
It doesn't put p_space as false, it just ignores the == 4 and when I debugged, I saw it got to that if statement.
Can someone please help.
Thanks.
If platformCollision returns 4 on the first call, it alters state, and will not return 4 on the second call.
void Player::playerCheckPlatCollision(SDL_Rect rect) {
int bang = platformCollision(p_hitboxPTR, rect);
if (bang == 3) {
setGravityF(0.0);
} else if (bang == 4) {
p_space = false;
}
}
I've implemented tilemap collision into my game, it works but the problem comes when I'm colliding on one axis and trying to move on the other. I can't slide along the wall.
in Player.cpp
void Player::update(float delta, std::vector<Tile>& tiles) {
if (sf::Keyboard::isKeyPressed(sf::Keyboard::W) || sf::Keyboard::isKeyPressed(sf::Keyboard::Up) || sf::Joystick::getAxisPosition(0, sf::Joystick::Y) < -20) {
newPos.y -= speed * delta;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::A) || sf::Keyboard::isKeyPressed(sf::Keyboard::Left) || sf::Joystick::getAxisPosition(0, sf::Joystick::X) < -20) {
newPos.x -= speed * delta;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::S) || sf::Keyboard::isKeyPressed(sf::Keyboard::Down) || sf::Joystick::getAxisPosition(0, sf::Joystick::Y) > 20) {
newPos.y += speed * delta;
}
if (sf::Keyboard::isKeyPressed(sf::Keyboard::D) || sf::Keyboard::isKeyPressed(sf::Keyboard::Right) || sf::Joystick::getAxisPosition(0, sf::Joystick::X) > 20) {
newPos.x += speed * delta;
}
sf::Vector2f oldPos = sprite.getPosition();
move(delta, newPos);
for (int i = 0; i < tiles.size(); i++) {
if (Collision::PixelPerfectTest(sprite, tiles[i].sprite) && tiles[i].collision) {
sprite.setPosition(oldPos);
newPos = oldPos;
}
}
}
void Player::move(float delta, sf::Vector2f position) {
sprite.setPosition(position);
}
In Collision.cpp
bool PixelPerfectTest(const sf::Sprite& Object1, const sf::Sprite& Object2, sf::Uint8 AlphaLimit) {
sf::FloatRect Intersection;
if (Object1.getGlobalBounds().intersects(Object2.getGlobalBounds(), Intersection)) {
sf::IntRect O1SubRect = Object1.getTextureRect();
sf::IntRect O2SubRect = Object2.getTextureRect();
sf::Uint8* mask1 = Bitmasks.GetMask(Object1.getTexture());
sf::Uint8* mask2 = Bitmasks.GetMask(Object2.getTexture());
// Loop through our pixels
for (int i = Intersection.left; i < Intersection.left + Intersection.width; i++) {
for (int j = Intersection.top; j < Intersection.top + Intersection.height; j++) {
sf::Vector2f o1v = Object1.getInverseTransform().transformPoint(i, j);
sf::Vector2f o2v = Object2.getInverseTransform().transformPoint(i, j);
// Make sure pixels fall within the sprite's subrect
if (o1v.x > 0 && o1v.y > 0 && o2v.x > 0 && o2v.y > 0 &&
o1v.x < O1SubRect.width && o1v.y < O1SubRect.height &&
o2v.x < O2SubRect.width && o2v.y < O2SubRect.height) {
if (Bitmasks.GetPixel(mask1, Object1.getTexture(), (int)(o1v.x) + O1SubRect.left, (int)(o1v.y) + O1SubRect.top) > AlphaLimit &&
Bitmasks.GetPixel(mask2, Object2.getTexture(), (int)(o2v.x) + O2SubRect.left, (int)(o2v.y) + O2SubRect.top) > AlphaLimit)
return true;
}
}
}
}
return false;
}
That's because your collision test is all or nothing. I would do extra collision tests to see if the x or y new position is valid or not, something like:
if (tiles[i].collision && Collision::PixelPerfectTest(sprite, tiles[i].sprite))
{
sf::Vector2f checkPosX = newPos;
sf::Vector2f checkPosY = newPos;
checkPosX.y = oldPos.y;
checkPosY.x = oldPos.x;
sprite.setPosition(checkPosX);
if (!Collision::PixelPerfectTest(sprite, tiles[i].sprite))
{
newPos = checkPosX;
}
else
{
sprite.setPosition(checkPosY);
if (!Collision::PixelPerfectTest(sprite, tiles[i].sprite))
{
newPos = checkPosY;
}
else
{
sprite.setPosition(oldPos);
newPos = oldPos;
}
}
}
As an aside, if you do test tiles[i].collision first you will skip the more expensive PixelPerfectTest() test for non-collision tiles due to the expression short-circuiting.
I posted a different question earlier that gave me a bug using D3DPT_TRIANGLEFAN but I tried to recode my circle differently. Only problem is that it doesn't draw to the screen... I have tried debugging it but everything seems to be going perfect which is weird.
Here is my whole "Circle' class (This is part of a larger program a Pong game)
class Circle: public physicsObject
{
public:
Circle(float x, float y, float r, D3DCOLOR col){
xVel=3;
yVel=3;
xLB=0.0;
xRB=800;
yUB=600;
yLB=0;
this->r=r;
this->x=x;
this->y=y;
for(float i = 0.0f; i<360.0f; i += 1.0f)
{
float angle = i;
points[(int)i].x = x + (sinD(angle) * r);
points[(int)i].y = y + (cosD(angle) * r);
points[(int)i].z = 0;
points[(int)i].Color = col;
}
}
void update()
{
for(int i = 0; i < paddles.size(); ++i)
{
if(paddles[i]->left)
{
if(x - r + xVel < paddles[i]->x + 20 && y+yVel > paddles[i]->y && y+yVel< paddles[i]->y+80){
xVel *= -1;
}
}else{
if(x + r + xVel > paddles[i]->x && y+yVel > paddles[i]->y && y+yVel< paddles[i]->y+80){
xVel *= -1;
}
}
}
if(x+r+10+xVel>xRB || x-r+xVel < xLB)
{
//MessageBox(0,"AWW SHEEIT","I LOSED",MB_OK);
//ExitProcess(0);
}
if(y+r+30+yVel > yUB || y-r+yVel < yLB)
yVel*=-1;
translate(xVel,yVel);
}
void translate(float x, float y)
{
if(GetAsyncKeyState(VK_SPACE))
{
gamestart = true;
}
if(gamestart){
this->x+=x;
this->y+=y;
for(int i = 0; i < 360; ++i)
{
points[i].x+=x;
points[i].y+=y;
}
}
}
void render()
{
update();
d3ddev->SetTexture(0,0);
d3ddev->SetFVF((D3DFVF_XYZRHW | D3DFVF_DIFFUSE));
d3ddev->SetRenderState( D3DRS_LIGHTING, FALSE);
d3ddev->SetRenderState( D3DRS_CULLMODE, D3DCULL_CCW);
d3ddev->SetRenderState( D3DRS_ALPHABLENDENABLE, TRUE );
d3ddev->SetRenderState( D3DRS_DESTBLEND, D3DBLEND_INVSRCALPHA );
d3ddev->SetRenderState( D3DRS_ZENABLE, D3DZB_FALSE );
d3ddev->SetRenderState( D3DRS_FOGENABLE, false);
d3ddev->DrawPrimitiveUP(D3DPT_TRIANGLEFAN, 360, &points, sizeof(360));
}
Vertex points [360];
private:
float r;
};
Thanks for the help ahead of time!