如何在 SFML 中检查二维地图上的碰撞?
How to check collision on 2D map in SFML?
我有一个 RectangleShape 墙,我为我的 2D 地图上的每个“1”绘制了一个对象:
int map[5][8] =
{
{ 1, 1, 1, 1, 1, 1, 1, 1 },
{ 1, 0, 0, 0, 0, 0, 0, 1 },
{ 1, 0, 1, 0, 1, 1, 0, 1 },
{ 1, 2, 1, 0, 0, 0, 3, 1 },
{ 1, 1, 1, 1, 1, 1, 1, 1 }
};
sf::RectangleShape player;
player.setSize(sf::Vector2f(32,32));
sf::RectangleShape wall;
wall.setSize(sf::Vector2f(32,32));
wall.setFillColor(sf::Color(40, 199, 40));
for (int mapX= 0; mapX< 8; mapX++)
{
for (int mapY= 0; mapY< 5; mapY++)
{
if (map[mapY][mapX] == 1)
{
wall.setPosition(mapX * 32, mapY * 32);
window.draw(wall);
}
}
}
我检查是否与下面列出的代码发生碰撞,但这仅适用于最后绘制的墙。如何解决这个问题?只有一个对象墙,我想为我的 2D 阵列贴图检查所有绘制的墙的碰撞。
if (event.type == sf::Event::TextEntered)
{
fPlayerY_t = fPlayerY;
fPlayerX_t = fPlayerX;
if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) fPlayerY_t = fPlayerY - 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) fPlayerY_t = fPlayerY + 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) fPlayerX_t = fPlayerX + 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) fPlayerX_t = fPlayerX - 32;
// temp pos
player.setPosition(fPlayerX_t, fPlayerY_t);
// collision with wall
if (player.getPosition().x == wall.getPosition().x &&
player.getPosition().y == wall.getPosition().y)
{
// back to prev position
player.setPosition(fPlayerX, fPlayerY);
}
else
{
// No collision
fPlayerX = fPlayerX_t;
fPlayerY = fPlayerY_t;
}
}
将玩家的坐标转换为数组坐标,然后检查是否map[x][y] == 1
。
所以不必在每个游戏循环中遍历整个地图。
转换成数组坐标,使用int
转换:
int playerTileX = (int)(playerWorldX / 32);
int playerTileY = (int)(playerWorldY / 32);
if(map[playerTileX ][playerTileY ] == 1)
{
// collision.
}
else
{
// no collision.
}
我不喜欢这个解决方案的地方:它只检查瓷砖碰撞,你必须确保每面墙的尺寸都相同(这里是 32*32)。
我有一个 RectangleShape 墙,我为我的 2D 地图上的每个“1”绘制了一个对象:
int map[5][8] =
{
{ 1, 1, 1, 1, 1, 1, 1, 1 },
{ 1, 0, 0, 0, 0, 0, 0, 1 },
{ 1, 0, 1, 0, 1, 1, 0, 1 },
{ 1, 2, 1, 0, 0, 0, 3, 1 },
{ 1, 1, 1, 1, 1, 1, 1, 1 }
};
sf::RectangleShape player;
player.setSize(sf::Vector2f(32,32));
sf::RectangleShape wall;
wall.setSize(sf::Vector2f(32,32));
wall.setFillColor(sf::Color(40, 199, 40));
for (int mapX= 0; mapX< 8; mapX++)
{
for (int mapY= 0; mapY< 5; mapY++)
{
if (map[mapY][mapX] == 1)
{
wall.setPosition(mapX * 32, mapY * 32);
window.draw(wall);
}
}
}
我检查是否与下面列出的代码发生碰撞,但这仅适用于最后绘制的墙。如何解决这个问题?只有一个对象墙,我想为我的 2D 阵列贴图检查所有绘制的墙的碰撞。
if (event.type == sf::Event::TextEntered)
{
fPlayerY_t = fPlayerY;
fPlayerX_t = fPlayerX;
if (sf::Keyboard::isKeyPressed(sf::Keyboard::W)) fPlayerY_t = fPlayerY - 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::S)) fPlayerY_t = fPlayerY + 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::D)) fPlayerX_t = fPlayerX + 32;
else if (sf::Keyboard::isKeyPressed(sf::Keyboard::A)) fPlayerX_t = fPlayerX - 32;
// temp pos
player.setPosition(fPlayerX_t, fPlayerY_t);
// collision with wall
if (player.getPosition().x == wall.getPosition().x &&
player.getPosition().y == wall.getPosition().y)
{
// back to prev position
player.setPosition(fPlayerX, fPlayerY);
}
else
{
// No collision
fPlayerX = fPlayerX_t;
fPlayerY = fPlayerY_t;
}
}
将玩家的坐标转换为数组坐标,然后检查是否map[x][y] == 1
。
所以不必在每个游戏循环中遍历整个地图。
转换成数组坐标,使用int
转换:
int playerTileX = (int)(playerWorldX / 32);
int playerTileY = (int)(playerWorldY / 32);
if(map[playerTileX ][playerTileY ] == 1)
{
// collision.
}
else
{
// no collision.
}
我不喜欢这个解决方案的地方:它只检查瓷砖碰撞,你必须确保每面墙的尺寸都相同(这里是 32*32)。