vertex_shader_v5.glsl Full Listing

vertex_shader_v5.glsl
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#version 330

// Time since burst start
uniform float time;

// (x, y) position passed in
in vec2 in_pos;

// Velocity of particle
in vec2 in_vel;

// Color of particle
in vec3 in_color;

// Fade rate
in float in_fade_rate;

// Output the color to the fragment shader
out vec4 color;

void main() {

    // Calculate alpha based on time and fade rate
    float alpha = 1.0 - (in_fade_rate * time);
    if(alpha < 0.0) alpha = 0;

    // Set the RGBA color
    color = vec4(in_color[0], in_color[1], in_color[2], alpha);

    // Adjust velocity based on gravity
    vec2 new_vel = in_vel;
    new_vel[1] -= time * 1.1;

    // Calculate a new position
    vec2 new_pos = in_pos + (time * new_vel);

    // Set the position. (x, y, z, w)
    gl_Position = vec4(new_pos, 0.0, 1);
}