precision mediump float; varying vec2 v_texCoord; uniform sampler2D u_tex; uniform float u_ar; //aspect ratio void main() { float schwarzchild = .2; vec2 offset = vec2(.5,.5); vec2 x = v_texCoord - offset; x.y *= u_ar; float r0 = length(x); if(r0<schwarzchild) gl_FragColor = vec4(0.0,0.0,0.0,1.0); else{ float theta = atan(x.y,x.x); float r = 2.0*sqrt(schwarzchild*(r0-schwarzchild)); gl_FragColor = texture2D(u_tex,vec2(r*cos(theta),r/u_ar*sin(theta))+offset); } }
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