Kelsidavis-WoWee/assets/shaders/minimap_display.frag.glsl

#version 450

layout(set = 0, binding = 0) uniform sampler2D uComposite;

layout(push_constant) uniform Push {
    vec4 rect;
    vec2 playerUV;
    float rotation;
    float arrowRotation;
    float zoomRadius;
    int squareShape;
} push;

layout(location = 0) in vec2 TexCoord;

layout(location = 0) out vec4 outColor;

float cross2d(vec2 a, vec2 b) {
    return a.x * b.y - a.y * b.x;
}

bool pointInTriangle(vec2 p, vec2 a, vec2 b, vec2 c) {
    float d1 = cross2d(b - a, p - a);
    float d2 = cross2d(c - b, p - b);
    float d3 = cross2d(a - c, p - c);
    bool hasNeg = (d1 < 0.0) || (d2 < 0.0) || (d3 < 0.0);
    bool hasPos = (d1 > 0.0) || (d2 > 0.0) || (d3 > 0.0);
    return !(hasNeg && hasPos);
}

void main() {
    vec2 center = TexCoord - 0.5;
    float dist = length(center);

    if (push.squareShape == 0) {
        if (dist > 0.5) discard;
    }

    float cs = cos(push.rotation);
    float sn = sin(push.rotation);
    vec2 rotated = vec2(center.x * cs - center.y * sn, center.x * sn + center.y * cs);
    vec2 mapUV = push.playerUV + rotated * push.zoomRadius * 2.0;

    vec4 mapColor = texture(uComposite, mapUV);

    // Player arrow
    float acs = cos(push.arrowRotation);
    float asn = sin(push.arrowRotation);
    vec2 ac = center;
    vec2 arrowPos = vec2(ac.x * acs - ac.y * asn, ac.x * asn + ac.y * acs);

    vec2 tip = vec2(0.0, -0.04);
    vec2 left = vec2(-0.02, 0.02);
    vec2 right = vec2(0.02, 0.02);

    if (pointInTriangle(arrowPos, tip, left, right)) {
        mapColor = vec4(1.0, 0.8, 0.0, 1.0);
    }

    // Dark border ring
    float border = smoothstep(0.48, 0.5, dist);
    if (push.squareShape == 0) {
        mapColor.rgb *= 1.0 - border * 0.7;
    }

    outColor = mapColor;
}