nx_tex_sample_mip_candidate_t218.nx source
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1import "nx_tex_sample.nx"
2import "nx_shader_ir.nx"
3// Area integration for one mip level. Input/output texture views carry sRGB transfer;
4// alpha remains linear. No alpha-test coverage rescaling is applied here.
5func txm_call1(m:*i64,name:*u8,e:i64,ty:i64)->i64{let c:i64=sir_call(m,name,ty);sir_arg(m,c,e);return c}
6func txm_call2(m:*i64,name:*u8,a:i64,b:i64,ty:i64)->i64{let c:i64=sir_call(m,name,ty);sir_arg(m,c,a);sir_arg(m,c,b);return c}
7func txm_f(m:*i64,s:*u8)->i64{return sir_lit(m,s,T_F32)}
8func txm_v2(m:*i64,x:i64,y:i64)->i64{let c:i64=sir_ctor(m,T_V2F);sir_arg(m,c,x);sir_arg(m,c,y);return c}
9func nx_txs_mip_fragment_v1()->*i64{
10 let m:*i64=sir_new();sir_uniform(m,"uSourceSize",T_V2F,0);sir_uniform(m,"uTargetSize",T_V2F,0);sir_texture(m,"uSource",T_TEX2F);sir_fragout(m,"fc",T_V4F,0)
11 let f:i64=sir_func(m,"main",T_VOID);sir_param_position(m,f,"position")
12 let src:i64=sir_ident(m,"uSourceSize",T_V2F);let dst:i64=sir_ident(m,"uTargetSize",T_V2F)
13 let pos:i64=sir_swz(m,sir_ident(m,"position",T_V4F),"xy",T_V2F)
14 let floorpos:i64=txm_call1(m,"floor",pos,T_V2F)
15 let lo:i64=sir_bin(m,"/",sir_bin(m,"*",floorpos,src,T_V2F),dst,T_V2F)
16 let one:i64=txm_v2(m,txm_f(m,"1.0"),txm_f(m,"1.0"))
17 let hi:i64=sir_bin(m,"/",sir_bin(m,"*",sir_bin(m,"+",floorpos,one,T_V2F),src,T_V2F),dst,T_V2F)
18 sir_stmt(m,f,sir_let(m,"lo",T_V2F,lo));sir_stmt(m,f,sir_let(m,"hi",T_V2F,hi))
19 let l:i64=sir_ident(m,"lo",T_V2F);let h:i64=sir_ident(m,"hi",T_V2F)
20 let z4:i64=sir_ctor(m,T_V4F);sir_arg(m,z4,txm_f(m,"0.0"));sir_stmt(m,f,sir_var(m,"sum",T_V4F,z4))
21 let yi:i64=sir_cast(m,txm_call1(m,"floor",sir_swz(m,l,"y",T_F32),T_F32),T_I32)
22 sir_stmt(m,f,sir_var(m,"iy",T_I32,yi))
23 let y:i64=sir_ident(m,"iy",T_I32);let x:i64=sir_ident(m,"ix",T_I32)
24 let yf:i64=sir_cast(m,y,T_F32);let xf:i64=sir_cast(m,x,T_F32)
25 let ystop:i64=sir_if(m,sir_bin(m,">=",yf,sir_swz(m,h,"y",T_F32),T_BOOL),sir_break(m),0)
26 let xi:i64=sir_cast(m,txm_call1(m,"floor",sir_swz(m,l,"x",T_F32),T_F32),T_I32)
27 let xinit:i64=sir_var(m,"ix",T_I32,xi)
28 let xstop:i64=sir_if(m,sir_bin(m,">=",xf,sir_swz(m,h,"x",T_F32),T_BOOL),sir_break(m),0)
29 let wx:i64=sir_bin(m,"-",txm_call2(m,"min",sir_swz(m,h,"x",T_F32),sir_bin(m,"+",xf,txm_f(m,"1.0"),T_F32),T_F32),txm_call2(m,"max",sir_swz(m,l,"x",T_F32),xf,T_F32),T_F32)
30 let wy:i64=sir_bin(m,"-",txm_call2(m,"min",sir_swz(m,h,"y",T_F32),sir_bin(m,"+",yf,txm_f(m,"1.0"),T_F32),T_F32),txm_call2(m,"max",sir_swz(m,l,"y",T_F32),yf,T_F32),T_F32)
31 let xy:i64=sir_ctor(m,T_V2I);sir_arg(m,xy,x);sir_arg(m,xy,y)
32 let tex:i64=sir_texload(m,sir_ident(m,"uSource",T_TEX2F),xy,sir_lit(m,"0",T_I32))
33 let sum:i64=sir_ident(m,"sum",T_V4F)
34 let add:i64=sir_assign(m,sum,sir_bin(m,"+",sum,sir_bin(m,"*",tex,sir_bin(m,"*",wx,wy,T_F32),T_V4F),T_V4F))
35 let incx:i64=sir_assign(m,x,sir_bin(m,"+",x,sir_lit(m,"1",T_I32),T_I32))
36 let xbody:i64=sir_seq(m,xstop,sir_seq(m,add,incx))
37 let incy:i64=sir_assign(m,y,sir_bin(m,"+",y,sir_lit(m,"1",T_I32),T_I32))
38 let ybody:i64=sir_seq(m,ystop,sir_seq(m,xinit,sir_seq(m,sir_loop(m,xbody),incy)))
39 sir_stmt(m,f,sir_loop(m,ybody))
40 let extent:i64=sir_bin(m,"-",h,l,T_V2F)
41 let area:i64=sir_bin(m,"*",sir_swz(m,extent,"x",T_F32),sir_swz(m,extent,"y",T_F32),T_F32)
42 sir_stmt(m,f,sir_assign(m,sir_ident(m,"fc",T_V4F),sir_bin(m,"/",sum,area,T_V4F)))
43 return m
44}