puts "========" puts "Per-pixel lighting using GLSL program (Phong shading), check lighting of back faces" puts "========" # create box box b 1 2 3 explode b F # draw box vclear vclose ALL vinit View1 vsetdispmode 1 vaxo vdisplay b_1 b_2 vfit vrotate 0.2 0.0 0.0 # take snapshot with fixed pipeline vdump $::imagedir/${::casename}_OFF.png set aColorB [vreadpixel 150 150 rgb name] set aColorF [vreadpixel 250 250 rgb name] if { "$aColorB" != "$aColorF"} { puts "Error: front/back colors are different!" } set aColorFixed $aColorF # activate phong shader vshaderprog phong set aColorB [vreadpixel 150 150 rgb name] set aColorF [vreadpixel 250 250 rgb name] if { "$aColorB" != "$aColorF"} { puts "Error: front/back colors are different!" } if { "$aColorF" != "$aColorFixed"} { puts "Error: colors are different!" }