non uniform border radius for quads

glow/src/quad/compatibility.rs

@@ -254,7 +254,7 @@ unsafe fn create_buffers(
     gl.enable_vertex_attrib_array(4);
     gl.vertex_attrib_pointer_f32(
         4,
-        1,
+        4,
         glow::FLOAT,
         false,
         stride,
@@ -268,7 +268,7 @@ unsafe fn create_buffers(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1),
+        4 * (2 + 2 + 4 + 4 + 4),
     );
 
     gl.enable_vertex_attrib_array(6);
@@ -278,7 +278,7 @@ unsafe fn create_buffers(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1 + 1),
+        4 * (2 + 2 + 4 + 4 + 4 + 1),
     );
 
     gl.bind_vertex_array(None);
@@ -307,7 +307,7 @@ pub struct Vertex {
     pub border_color: [f32; 4],
 
     /// The border radius of the [`Vertex`].
-    pub border_radius: f32,
+    pub border_radius: [f32; 4],
 
     /// The border width of the [`Vertex`].
     pub border_width: f32,
@@ -325,7 +325,7 @@ impl Vertex {
             size: quad.size,
             color: quad.color,
             border_color: quad.color,
-            border_radius: quad.border_radius,
+            border_radius: [quad.border_radius[0]; 4],
             border_width: quad.border_width,
             q_position: [0.0, 0.0],
         };

glow/src/quad/core.rs

@@ -218,7 +218,7 @@ unsafe fn create_instance_buffer(
     gl.enable_vertex_attrib_array(4);
     gl.vertex_attrib_pointer_f32(
         4,
-        1,
+        4,
         glow::FLOAT,
         false,
         stride,
@@ -233,7 +233,7 @@ unsafe fn create_instance_buffer(
         glow::FLOAT,
         false,
         stride,
-        4 * (2 + 2 + 4 + 4 + 1),
+        4 * (2 + 2 + 4 + 4 + 4),
     );
     gl.vertex_attrib_divisor(5, 1);
 

glow/src/shader/core/quad.frag

@@ -17,7 +17,7 @@ in vec4 v_Color;
 in vec4 v_BorderColor;
 in vec2 v_Pos;
 in vec2 v_Scale;
-in float v_BorderRadius;
+in vec4 v_BorderRadius;
 in float v_BorderWidth;
 
 float fDistance(vec2 frag_coord, vec2 position, vec2 size, float radius)
@@ -38,14 +38,30 @@ float fDistance(vec2 frag_coord, vec2 position, vec2 size, float radius)
     return sqrt(distance.x * distance.x + distance.y * distance.y);
 }
 
+float selectBorderRadius(vec4 radi, vec2 position, vec2 center)
+{
+    float rx = radi.x;
+    float ry = radi.y;
+    rx = position.x > center.x ? radi.y : radi.x;
+    ry = position.x > center.x ? radi.z : radi.w;
+    rx = position.y > center.y ? ry : rx;
+    return rx;
+}
+
 void main() {
     vec4 mixed_color;
 
     vec2 fragCoord = vec2(gl_FragCoord.x, u_ScreenHeight - gl_FragCoord.y);
 
+    float borderRadius = selectBorderRadius(
+        v_BorderRadius,
+        fragCoord,
+        (v_Pos + v_Scale * 0.5).xy
+    );
+
     // TODO: Remove branching (?)
     if(v_BorderWidth > 0.0) {
-        float internal_border = max(v_BorderRadius - v_BorderWidth, 0.0);
+        float internal_border = max(borderRadius - v_BorderWidth, 0.0);
 
         float internal_distance = fDistance(
             fragCoord,
@@ -69,11 +85,11 @@ void main() {
         fragCoord,
         v_Pos,
         v_Scale,
-        v_BorderRadius
+        borderRadius
     );
 
     float radius_alpha =
-        1.0 - smoothstep(max(v_BorderRadius - 0.5, 0.0), v_BorderRadius + 0.5, d);
+        1.0 - smoothstep(max(borderRadius - 0.5, 0.0), borderRadius + 0.5, d);
 
     gl_FragColor = vec4(mixed_color.xyz, mixed_color.w * radius_alpha);
 }

glow/src/shader/core/quad.vert

@@ -5,14 +5,14 @@ in vec2 i_Pos;
 in vec2 i_Scale;
 in vec4 i_Color;
 in vec4 i_BorderColor;
-in float i_BorderRadius;
+in vec4 i_BorderRadius;
 in float i_BorderWidth;
 
 out vec4 v_Color;
 out vec4 v_BorderColor;
 out vec2 v_Pos;
 out vec2 v_Scale;
-out float v_BorderRadius;
+out vec4 v_BorderRadius;
 out float v_BorderWidth;
 
 vec2 positions[4] = vec2[](
@@ -27,9 +27,11 @@ void main() {
     vec2 p_Pos = i_Pos * u_Scale;
     vec2 p_Scale = i_Scale  * u_Scale;
 
-    float i_BorderRadius = min(
-        i_BorderRadius,
-        min(i_Scale.x, i_Scale.y) / 2.0
+    vec4 i_BorderRadius = vec4(
+        min(i_BorderRadius.x, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.y, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.z, min(i_Scale.x, i_Scale.y) / 2.0),
+        min(i_BorderRadius.w, min(i_Scale.x, i_Scale.y) / 2.0)
     );
 
     mat4 i_Transform = mat4(