-#version 140
+#version 100
uniform mat4 perspective;
uniform mat4 view;
uniform mat4 model;
uniform vec2 z0;
-in vec3 position;
-out vec2 c;
-out vec2 z;
+attribute mediump vec3 position;
+varying mediump vec2 c;
+varying mediump vec2 z;
void main() {
mat4 modelview = view * model;