Cycles: Move watertight triangle intersection to an utility file

This way the code can be reused more easily.

1 files changed, 21 insertions, 127 deletions

diff --git a/intern/cycles/kernel/geom/geom_triangle_intersect.h b/intern/cycles/kernel/geom/geom_triangle_intersect.h
index 12700c7a246..ea2ee5c3536 100644
--- a/intern/cycles/kernel/geom/geom_triangle_intersect.h
+++ b/intern/cycles/kernel/geom/geom_triangle_intersect.h
@@ -48,145 +48,39 @@ ccl_device_inline bool triangle_intersect(KernelGlobals *kg,
                                           int object,
                                           int prim_addr)
 {
-	const int kx = isect_precalc->kx;
-	const int ky = isect_precalc->ky;
-	const int kz = isect_precalc->kz;
-	const float Sx = isect_precalc->Sx;
-	const float Sy = isect_precalc->Sy;
-	const float Sz = isect_precalc->Sz;
-
-	/* Calculate vertices relative to ray origin. */
 	const uint tri_vindex = kernel_tex_fetch(__prim_tri_index, prim_addr);
 
 #if defined(__KERNEL_AVX2__) && defined(__KERNEL_SSE__)
-	const avxf avxf_P(P.m128, P.m128);
-
-	const ssef *ssef_verts = (ssef*)&kg->__prim_tri_verts.data[tri_vindex];
-	const avxf tri_ab = _mm256_loadu_ps((float *)(ssef_verts));
-	const avxf tri_bc = _mm256_loadu_ps((float *)(ssef_verts + 1));
-
-	const avxf AB = tri_ab - avxf_P;
-	const avxf BC = tri_bc - avxf_P;
-
-	const __m256i permute_mask = _mm256_set_epi32(0x3, kz, ky, kx, 0x3, kz, ky, kx);
-
-	const avxf AB_k = shuffle(AB, permute_mask);
-	const avxf BC_k = shuffle(BC, permute_mask);
-
-	/* Akz, Akz, Bkz, Bkz, Bkz, Bkz, Ckz, Ckz */
-	const avxf ABBC_kz = shuffle<2>(AB_k, BC_k);
-
-	/* Akx, Aky, Bkx, Bky, Bkx,Bky, Ckx, Cky */
-	const avxf ABBC_kxy = shuffle<0,1,0,1>(AB_k, BC_k);
-
-	const avxf Sxy(Sy, Sx, Sy, Sx);
-
-	/* Ax, Ay, Bx, By, Bx, By, Cx, Cy */
-	const avxf ABBC_xy = nmadd(ABBC_kz, Sxy, ABBC_kxy);
-
-	float ABBC_kz_array[8];
-	_mm256_storeu_ps((float*)&ABBC_kz_array, ABBC_kz);
-
-	const float A_kz = ABBC_kz_array[0];
-	const float B_kz = ABBC_kz_array[2];
-	const float C_kz = ABBC_kz_array[6];
-
-	/* By, Bx, Cy, Cx, By, Bx, Ay, Ax */
-	const avxf BCBA_yx = permute<3,2,7,6,3,2,1,0>(ABBC_xy);
-
-	const avxf neg_mask(0,0,0,0,0x80000000, 0x80000000, 0x80000000, 0x80000000);
-
-	/* W           U                             V
-	 * (AxBy-AyBx) (BxCy-ByCx) XX XX (BxBy-ByBx) (CxAy-CyAx) XX XX
-	 */
-	const avxf WUxxxxVxx_neg = _mm256_hsub_ps(ABBC_xy * BCBA_yx, neg_mask /* Dont care */);
-
-	const avxf WUVWnegWUVW = permute<0,1,5,0,0,1,5,0>(WUxxxxVxx_neg) ^ neg_mask;
-
-	/* Calculate scaled barycentric coordinates. */
-	float WUVW_array[4];
-	_mm_storeu_ps((float*)&WUVW_array, _mm256_castps256_ps128 (WUVWnegWUVW));
-
-	const float W = WUVW_array[0];
-	const float U = WUVW_array[1];
-	const float V = WUVW_array[2];
-
-	const int WUVW_mask = 0x7 & _mm256_movemask_ps(WUVWnegWUVW);
-	const int WUVW_zero = 0x7 & _mm256_movemask_ps(_mm256_cmp_ps(WUVWnegWUVW,
-	                                               _mm256_setzero_ps(), 0));
-
-	if(!((WUVW_mask == 7) || (WUVW_mask == 0)) && ((WUVW_mask | WUVW_zero) != 7)) {
-		return false;
-	}
+	const ssef *verts = (ssef*)&kg->__prim_tri_verts.data[tri_vindex];
 #else
 	const float4 tri_a = kernel_tex_fetch(__prim_tri_verts, tri_vindex+0),
 	             tri_b = kernel_tex_fetch(__prim_tri_verts, tri_vindex+1),
 	             tri_c = kernel_tex_fetch(__prim_tri_verts, tri_vindex+2);
-	const float3 A = make_float3(tri_a.x - P.x, tri_a.y - P.y, tri_a.z - P.z);
-	const float3 B = make_float3(tri_b.x - P.x, tri_b.y - P.y, tri_b.z - P.z);
-	const float3 C = make_float3(tri_c.x - P.x, tri_c.y - P.y, tri_c.z - P.z);
-
-	const float A_kx = IDX(A, kx), A_ky = IDX(A, ky), A_kz = IDX(A, kz);
-	const float B_kx = IDX(B, kx), B_ky = IDX(B, ky), B_kz = IDX(B, kz);
-	const float C_kx = IDX(C, kx), C_ky = IDX(C, ky), C_kz = IDX(C, kz);
-
-	/* Perform shear and scale of vertices. */
-	const float Ax = A_kx - Sx * A_kz;
-	const float Ay = A_ky - Sy * A_kz;
-	const float Bx = B_kx - Sx * B_kz;
-	const float By = B_ky - Sy * B_kz;
-	const float Cx = C_kx - Sx * C_kz;
-	const float Cy = C_ky - Sy * C_kz;
-
-	/* Calculate scaled barycentric coordinates. */
-	float U = Cx * By - Cy * Bx;
-	float V = Ax * Cy - Ay * Cx;
-	float W = Bx * Ay - By * Ax;
-	if((U < 0.0f || V < 0.0f || W < 0.0f) &&
-	   (U > 0.0f || V > 0.0f || W > 0.0f))
-	{
-		return false;
-	}
+	const float3 verts[3] = {float4_to_float3(tri_a),
+	                         float4_to_float3(tri_b),
+	                         float4_to_float3(tri_c)};
 #endif
-
-	/* Calculate determinant. */
-	float det = U + V + W;
-	if(UNLIKELY(det == 0.0f)) {
-		return false;
-	}
-
-	/* Calculate scaled z-coordinates of vertices and use them to calculate
-	 * the hit distance.
-	 */
-	const float T = (U * A_kz + V * B_kz + W * C_kz) * Sz;
-	const int sign_det = (__float_as_int(det) & 0x80000000);
-	const float sign_T = xor_signmask(T, sign_det);
-	if((sign_T < 0.0f) ||
-	   (sign_T > isect->t * xor_signmask(det, sign_det)))
+	float t, u, v;
+	if(ray_triangle_intersect(isect_precalc,
+	                          P, isect->t,
+	                          verts,
+	                          &u, &v, &t))
 	{
-		return false;
-	}
-
 #ifdef __VISIBILITY_FLAG__
-	/* visibility flag test. we do it here under the assumption
-	 * that most triangles are culled by node flags */
-	if(kernel_tex_fetch(__prim_visibility, prim_addr) & visibility)
+		/* Visibility flag test. we do it here under the assumption
+		 * that most triangles are culled by node flags.
+		 */
+		if(kernel_tex_fetch(__prim_visibility, prim_addr) & visibility)
 #endif
-	{
-#ifdef __KERNEL_CUDA__
-		if(A == B && B == C) {
-			return false;
+		{
+			isect->prim = prim_addr;
+			isect->object = object;
+			isect->type = PRIMITIVE_TRIANGLE;
+			isect->u = u;
+			isect->v = v;
+			isect->t = t;
+			return true;
 		}
-#endif
-		/* Normalize U, V, W, and T. */
-		const float inv_det = 1.0f / det;
-		isect->prim = prim_addr;
-		isect->object = object;
-		isect->type = PRIMITIVE_TRIANGLE;
-		isect->u = U * inv_det;
-		isect->v = V * inv_det;
-		isect->t = T * inv_det;
-		return true;
 	}
 	return false;
 }