每年年底我都会制作烟花燃放 Canvas 效果(Javascript),最后一个是:
http://js1k.com/2011-dysentery/demo/955
这个效果很简单:用createRadialGradient()方法填充很多圆圈,并具有一定的透明度。 secret 在于属性:
globalCompositeOperation = "lighter";
使用时,所有颜色混合在一起,给人一种光的感觉。今年,我想做同样的事情,但是用 SFML/C++。我是 SFML 的初学者,不知道从哪里开始制作这种效果。谁能告诉我如何在 SFML 中模拟 Canvas globalCompositeOperation() ?
最佳答案
您可以使用sf::Blend::Mode
获得此效果。请参阅此示例:
#include <SFML/Graphics.hpp>
int main()
{
sf::RenderWindow window(sf::VideoMode(400, 400), "Blend::Mode Sample");
sf::Shape square = sf::Shape::Rectangle(100, 100, 200, 200, sf::Color(250, 30, 30));
sf::Shape circle1 = sf::Shape::Circle(100, 100, 50, sf::Color(30, 30, 250));
sf::Shape circle2 = sf::Shape::Circle(300, 100, 50, sf::Color(30, 30, 250));
sf::Shape circle3 = sf::Shape::Circle(100, 300, 50, sf::Color(30, 30, 250));
sf::Shape circle4 = sf::Shape::Circle(300, 300, 50, sf::Color(30, 30, 250));
circle1.SetBlendMode(sf::Blend::Alpha);
circle2.SetBlendMode(sf::Blend::Add);
circle3.SetBlendMode(sf::Blend::Multiply);
circle4.SetBlendMode(sf::Blend::None);
while (window.IsOpened())
{
sf::Event event;
while (window.PollEvent(event))
if (event.Type == sf::Event::Closed)
window.Close();
window.Clear();
window.Draw(square);
window.Draw(circle1);
window.Draw(circle2);
window.Draw(circle3);
window.Draw(circle4);
window.Display();
}
}
输出:
我认为您想要的效果是SetBlendMode(sf::Blend::Add)
。
关于c++ - 如何像Canvas globalCompositeOperation那样模拟更亮的效果?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8452301/