BLT-With-Graphics-Template/include/blt/gfx/renderer/shaders/pp_highlight.frag

#ifdef __cplusplus
#include <string>
const std::string shader_highlight_frag = R"("
#version 300 es
precision mediump float;

out vec4 FragColor;
in vec2 uv;
in vec2 pos;

uniform sampler2D tex;
uniform ivec4 size;
uniform vec4 mousePos;

void main() {
    vec2 texelSize = 1.0 / vec2(float(size.x), float(size.y));
    vec4 result = vec4(0.0, 0.0, 0.0, 0.0);
    for (int x = -size.z; x <= size.z; ++x) {
        for (int y = -size.w; y <= size.w; ++y) {
            vec2 offset = (vec2(float(x), float(y)) * texelSize);
            result += texture(tex, uv + offset);
        }
    }

    float dx = (gl_FragCoord.x - mousePos.x) / float(size.x);
    float dy = (gl_FragCoord.y - mousePos.y) / float(size.y);

    float distx = 1.0 - sqrt(dx * dx);
    float disty = 1.0 - sqrt(dy * dy);

    float dist = (distx + disty) / 2.0;

    vec4 n_color = result / vec4((float(size.z) * 2.0 + 1.0) * (float(size.w) * 2.0 + 1.0));

    n_color = n_color * vec4(16.0);

    if (dist >= 0.5)
        FragColor = normalize(n_color);
    else
        FragColor = texture(tex, uv);
    //FragColor = ;
}

")";
#endif