prim.edgeflag[i] = ctx->ac.i1false;
}
- /* Geometry shaders output triangle strips, but NGG expects triangles.
- * We need to change the vertex order for odd triangles to get correct
- * front/back facing by swapping 2 vertex indices, but we also have to
- * keep the provoking vertex in the same place.
- *
- * If the first vertex is provoking, swap index 1 and 2.
- * If the last vertex is provoking, swap index 0 and 1.
- */
+ /* Geometry shaders output triangle strips, but NGG expects triangles. */
if (verts_per_prim == 3) {
LLVMValueRef is_odd = LLVMBuildLShr(builder, flags, ctx->ac.i8_1, "");
is_odd = LLVMBuildTrunc(builder, is_odd, ctx->i1, "");
si_unpack_param(ctx, ctx->vs_state_bits, 4, 2),
ctx->i32_0, "");
- struct ac_ngg_prim in = prim;
- prim.index[0] = LLVMBuildSelect(builder, flatshade_first,
- in.index[0],
- LLVMBuildSelect(builder, is_odd,
- in.index[1], in.index[0], ""), "");
- prim.index[1] = LLVMBuildSelect(builder, flatshade_first,
- LLVMBuildSelect(builder, is_odd,
- in.index[2], in.index[1], ""),
- LLVMBuildSelect(builder, is_odd,
- in.index[0], in.index[1], ""), "");
- prim.index[2] = LLVMBuildSelect(builder, flatshade_first,
- LLVMBuildSelect(builder, is_odd,
- in.index[1], in.index[2], ""),
- in.index[2], "");
+ ac_build_triangle_strip_indices_to_triangle(&ctx->ac, is_odd,
+ flatshade_first,
+ prim.index);
}
ac_build_export_prim(&ctx->ac, &prim);