rewritten borders, fixed msaa

src/render/shaders/Border.hpp

@@ -0,0 +1,91 @@
+#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;
+}
+)#";