r500/drm/rotate.vs.asm

30 lines
1.0 KiB
NASM

-- CONST[0] = {0.159155, 0.5, 6.283185, -3.141593}
-- CONST[1] = {rotate, _, _, _}
-- each instruction is only allowed to use a single unique `const` address
--
-- instructions may use multiple `temp` addresses, so const[1] is moved to
-- temp[0]:
--
temp[0].x = VE_ADD const[1].x___ const[1].0___ ;
-- ME_SIN and ME_COS clamp their inputs to [-π,+π] prior to the sin/cos
-- calculation.
--
-- This 3-instruction sequence remaps the range [-,+] to [-π,+π]
temp[1].x = VE_MAD temp[0].x___ const[0].x___ const[0].y___ ;
temp[2].x = VE_FRC temp[1].x___ ;
temp[3].x = VE_MAD temp[2].x___ const[0].z___ const[0].w___ ;
temp[4].x = ME_SIN temp[3].___x ;
temp[4].y = ME_COS temp[3].___x ;
-- with sin and cos calculated, this now ordinary two-dimensional rotation:
--
-- x = position.x * cost - position.y * sint
-- y = position.x * sint + position.y * cost
-- z = 0
-- w = 1
temp[5].xy = VE_MUL input[0].yy__ temp[4].xy__ ;
out[0].xyzw = VE_MAD input[0].xx01 temp[4].yx01 temp[5].-xy00 ;