= 0.5) { tmp = colB; colB = colH; colH = tmp; } //E1 (or E3): swap B and H if(sel.x >= 0.5) { tmp = colF; colF = colD; colD = tmp; } //E2 (or E3): swap D and F if(colB == colD && colB != colF && colD != colH) { //do the Scale2x rule col = colD; } gl_FragColor = col; } ]]>