ch24p3_sharpen.ps

游戏开发特殊技巧-special.effects.game.programming

// this pixel shader sharpens the image.

ps.1.1

tex t0 
tex t1
tex t2
tex t3

// r0 = 4*t0 - t1 - t2 - t3
// rearranged, this is r0 = t0 - t1 + t0 - t2 + t0 - t3 + t0

mov     r0, t0
sub     r0, r0,   t1
add     r0, r0,   t0
sub     r0, r0,   t2
add     r0, r0,   t0
sub     r0, r0,   t3
add     r0, r0,   t0