stk-code_catmod/data/shaders/simple_particle.vert

uniform int flips;

#ifdef Explicit_Attrib_Location_Usable

layout(location = 0) in vec3 Position;
layout(location = 1) in vec4 mixed_color;
layout(location = 2) in vec2 lifetime_and_size;

layout(location = 3) in vec2 Texcoord;
layout(location = 4) in vec2 quadcorner;

layout(location = 6) in float anglespeed;
#else

in vec3 Position;
in vec4 mixed_color;
in vec2 lifetime_and_size;

in vec2 Texcoord;
in vec2 quadcorner;

in float anglespeed;
#endif

out vec2 tc;
out vec4 pc;

void main(void)
{
    if (lifetime_and_size.y == 0.0)
    {
        gl_Position = vec4(0.);
        return;
    }
    tc = Texcoord;
    pc = mixed_color.zyxw * smoothstep(1.0, 0.8, lifetime_and_size.x);
#if !defined(sRGB_Framebuffer_Usable) && !defined(Advanced_Lighting_Enabled)
    pc.rgb = pow(pc.rgb, vec3(1.0 / 2.2));
#endif
    vec4 viewpos = vec4(0.);
    if (flips == 1)
    {
        float angle = lifetime_and_size.x * anglespeed;
        float sin_a = sin(mod(angle / 2.0, 6.283185307179586));
        float cos_a = cos(mod(angle / 2.0, 6.283185307179586));
        vec4 quat = normalize(vec4(vec3(0.0, 1.0, 0.0) * sin_a, cos_a));
        vec3 newquadcorner = lifetime_and_size.y * vec3(quadcorner, 0.);
        newquadcorner = newquadcorner + 2.0 * cross(cross(newquadcorner,
            quat.xyz) + quat.w * newquadcorner, quat.xyz);
        viewpos = ViewMatrix * vec4(Position + newquadcorner, 1.0);
    }
    else
    {
        viewpos = ViewMatrix * vec4(Position, 1.0);
        viewpos += lifetime_and_size.y * vec4(quadcorner, 0., 0.);
    }
    gl_Position = ProjectionMatrix * viewpos;
}