1 files changed, 13 insertions, 8 deletions

diff --git a/assets/shaders/Taper.vert.glsl b/assets/shaders/Taper.vert.glsl
index 46f04fb3..82151f13 100644
--- a/assets/shaders/Taper.vert.glsl
+++ b/assets/shaders/Taper.vert.glsl
@@ -20,6 +20,7 @@ uniform float u_limit1;
 uniform float u_limit2;
 uniform float u_limit3;
 uniform float u_taperAmount;
+uniform float u_center;
 
 uniform vec4 color;
 
@@ -31,31 +32,35 @@ uniform mat4 u_worldMatrix;
 
 varying vec4 v_color;
 
+float TaperAmount( float param )
+{
+        float y0 = 1.0,  y1 = 1.0,  y2 = 0.0,  y3 = 0.0;
+        float yA0 = y0 + param*(y1 - y0),  yA1 = y1 + param*(y2 - y1),  yA2 = y2 + param*(y3 - y2);
+        float yB0 = yA0 + param*(yA1 - yA0),  yB1 = yA1 + param*(yA2 - yA1);
+        float yC0 = yB0 + param*(yB1 - yB0);
+
+        return yC0;
+}
 
 void main(void)
 {
         vec3 pos = vert;
         vec2 uv = texcoord;
 
-        v_color = vec4(0, 1, 0, 1);
+        v_color = vec4(texcoord.x, texcoord.y, 0, 1);
         if (uv.x > u_limit1)
         {
                 if (uv.x < u_limit2)
                 {
                         float t = (uv.x - u_limit1)/(u_limit2 - u_limit1);
-                        pos.y = pos.y - t*u_taperAmount;
-                        v_color = vec4( 1, 1, 0, 1 );
+                        pos.y = pos.y - pos.y*TaperAmount(t)*u_taperAmount;
                 }
                 else if (uv.x < u_limit3)
                 {
                         float t = 1.0 - (uv.x - u_limit2)/(u_limit3 - u_limit2);
-                        pos.y = pos.y - t*u_taperAmount;
-                        v_color = vec4( 0, 1, 1, 1 );
+                        pos.y = pos.y - pos.y*TaperAmount(t)*u_taperAmount;
                 }
-                else
-                        v_color = vec4(0,0,1,1);
         }
 
-
         gl_Position = u_projMatrix * u_mvMatrix * vec4(pos,1.0) ;
 }
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