working framebuffers, textures and feedback

shaders/frag.glsl

@@ -2,15 +2,15 @@
 
 uniform float iTime;
 uniform vec2 iResolution;
-uniform sampler2D frame0;
 in vec2 vUV;
-layout(location = 0) out vec4 fragColor;
+out vec3 fragColor;
+uniform sampler2D frame0;
 
 void main() {
     vec2 uv0 = vUV.st;
     float ratio = iResolution.x / iResolution.y;
     vec2 uv1 = (uv0 - .5) * vec2(ratio, 1);
     vec3 color = vec3(vUV, sin(iTime * 0.5) * 0.5 + 0.5);
-    color *= 1 - step(cos(iTime) * 0.1 + 0.5,length(uv1));
-    fragColor = vec4(color, 1.0);
+    color *= 1 - step(cos(iTime) * 0.1 + 0.4, length(uv1));
+    fragColor = color + texture(frame0, vUV - 0.01).xyz * 0.5;
 }