CSE380/hw3/dist/hw3_assets/shaders/linear_gradient_circle.fshader

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2022-05-23 06:00:37 -04:00
precision mediump float;
varying vec4 v_Position;
uniform vec4 circle_Color;
uniform vec4 default_Color;
// HOMEWORK 3
/*
The fragment shader is where pixel colors are decided.
You'll have to modify this code to make the circle vary between 2 colors.
Currently this will render the exact same thing as the gradient_circle shaders
*/
void main(){
// Default alpha is 0
float alpha = 0.0;
// Radius is 0.5, since the diameter of our quad is 1
float radius = 0.5;
float ratio = (1.0-(v_Position.x+0.25+v_Position.y+0.25));
// Get the distance squared of from (0, 0)
float dist_sq = v_Position.x*v_Position.x + v_Position.y*v_Position.y;
if(dist_sq < radius*radius){
// Multiply by 4, since distance squared is at most 0.25
alpha = 1.0;
}
// Use the alpha value in our color
gl_FragColor = vec4(default_Color[0]*ratio+circle_Color[0]*(1.0-ratio), default_Color[1]*ratio+circle_Color[1]*(1.0-ratio), default_Color[2]*ratio+circle_Color[2]*(1.0-ratio), default_Color[3]*ratio+circle_Color[3]*(1.0-ratio));
gl_FragColor.a = alpha;
}