ExperimentalGear/shaders/radarVertex.vs

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2023-11-13 01:41:52 +01:00
#version 330
#extension GL_ARB_separate_shader_objects : enable
const float PI = 3.1415926535897932384626433832795;
const float PI_2 = 1.57079632679489661923;
layout(location=0) in vec2 inPos;
layout(location=1) in vec2 inTex;
out gl_PerVertex
{
vec4 gl_Position;
};
layout(location=1) out vec2 fsTex;
layout(location=2) out vec4 vertexColor;
uniform mat4 proj;
uniform mat4 world;
uniform vec4 colorCenter;
uniform vec4 colorMax;
uniform float maxSize;
// Polar coordinate utility functions
float hypot(vec2 pos)
{
return sqrt(pos.x * pos.x + pos.y * pos.y);
}
/*
float atan2(vec2 pos)
{
if (pos.x > 0)
{
return atan(pos.y / pos.x);
}
if (pos.x < 0 && pos.y >= 0)
{
return atan(pos.y / pos.x) + PI;
}
if (pos.x < 0 && pos.y < 0)
{
return atan(pos.y / pos.x) - PI;
}
if (pos.x == 0 && pos.y > 0)
{
return PI_2;
}
if (pos.x == 0 && pos.y < 0)
{
return -PI_2;
}
// The following is not mathematically correct, as it's undefined
return 0.0;
}
vec2 toPolar(vec2 cartesian)
{
return vec2(hypot(pos), atan2(pos));
}
*/
float lerp(float x, vec2 p0, vec2 p1)
{
return p0.y + (p1.y - p0.y) * ((x - p0.x)/(p1.x - p0.x));
}
// x is in [0.0, 1.0]
vec4 lerpColor(float x, vec4 color1, vec4 color2)
{
return color1 + (color2 - color1) * x;
}
vec4 coordToColor(vec2 pos, float maxSize)
{
float r = hypot(pos);
//float phi = atan2(pos);
float factor = lerp(r, vec2(0,0), vec2(maxSize,1));
return lerpColor(factor, colorCenter, colorMax);
}
void main()
{
gl_Position = proj * world * vec4(inPos.xy, 0, 1);
vertexColor = coordToColor(inPos.xy, maxSize);
}