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#pragma once
#include <string>
// makes a stencil without corners
inline const std::string FRAGBORDER1 = R"#(
precision mediump float;
varying vec4 v_color;
varying vec2 v_texcoord;
uniform vec2 topLeft;
uniform vec2 bottomRight;
uniform vec2 fullSize;
uniform float radius;
uniform float thick;
uniform int primitiveMultisample;
float getOpacityForPixAndCorner(vec2 pix, vec2 corner) {
if (primitiveMultisample == 0) {
float dis = distance(pix + vec2(0.5, 0.5), corner);
return dis < radius && dis > radius - thick ? 1.0 : 0.0;
}
float distance1 = distance(pix + vec2(0.25, 0.25), corner);
float distance2 = distance(pix + vec2(0.75, 0.25), corner);
float distance3 = distance(pix + vec2(0.25, 0.75), corner);
float distance4 = distance(pix + vec2(0.75, 0.75), corner);
float v1 = distance1 < radius && distance1 > radius - thick ? 1.0 : 0.0;
float v2 = distance2 < radius && distance2 > radius - thick ? 1.0 : 0.0;
float v3 = distance3 < radius && distance3 > radius - thick ? 1.0 : 0.0;
float v4 = distance4 < radius && distance4 > radius - thick ? 1.0 : 0.0;
return (v1 + v2 + v3 + v4) / 4.0;
}
void main() {
vec2 pixCoord = fullSize * v_texcoord;
vec4 pixColor = v_color;
bool done = false;
// check for edges
if (pixCoord[0] < topLeft[0]) {
if (pixCoord[1] < topLeft[1]) {
// top left
pixColor[3] = pixColor[3] * getOpacityForPixAndCorner(pixCoord, topLeft + vec2(1,1));
done = true;
} else if (pixCoord[1] > bottomRight[1]) {
// bottom left
pixColor[3] = pixColor[3] * getOpacityForPixAndCorner(pixCoord, vec2(topLeft[0] + 1.0, bottomRight[1]));
done = true;
}
} else if (pixCoord[0] > bottomRight[0]) {
if (pixCoord[1] < topLeft[1]) {
// top right
pixColor[3] = pixColor[3] * getOpacityForPixAndCorner(pixCoord, vec2(bottomRight[0], topLeft[1] + 1.0));
done = true;
} else if (pixCoord[1] > bottomRight[1]) {
// bottom right
pixColor[3] = pixColor[3] * getOpacityForPixAndCorner(pixCoord, bottomRight);
done = true;
}
}
// now check for other shit
if (!done) {
// distance to all straight bb borders
float distanceT = pixCoord[1];
float distanceB = fullSize[1] - pixCoord[1];
float distanceL = pixCoord[0];
float distanceR = fullSize[0] - pixCoord[0];
// get the smallest
float smallest = min(min(distanceT, distanceB), min(distanceL, distanceR));
if (smallest > thick) {
discard; return;
}
}
if (pixColor[3] == 0.0) {
discard; return;
}
gl_FragColor = pixColor;
}
)#";
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