daily update on 20240407 by nitload youmu

2024-04-07 15:08:52 +08:00
parent 127fcdbfd3
commit e1e416bb41
141 changed files with 2578 additions and 2576 deletions
@@ -0,0 +1,31 @@
+#include "StgSharpC.h"
+#include "ssgc_internal.h"
+
+SSCAPI void SSCDECL normalize(__m128* source, __m128* target)
+{
+    // 计算source的长度的平方
+    __m128 a_length_sq = _mm_mul_ps(*source, *source); // 向量点乘自身
+    a_length_sq = _mm_add_ps(a_length_sq, _mm_shuffle_ps(a_length_sq, a_length_sq, _MM_SHUFFLE(2, 3, 0, 1)));
+    a_length_sq = _mm_add_ss(a_length_sq, _mm_shuffle_ps(a_length_sq, a_length_sq, _MM_SHUFFLE(0, 0, 3, 2)));
+
+    // 归一化向量source
+    __m128 a_inv_length = _mm_rsqrt_ps(a_length_sq); // 计算source长度的倒数平方根
+    *source = _mm_mul_ps(*source, a_inv_length); // 用source乘以其长度的倒数平方根得到单位向量
+
+    // 计算target与source的点积
+    __m128 dot_product = _mm_mul_ps(*target, *source);
+    dot_product = _mm_add_ps(dot_product, _mm_shuffle_ps(dot_product, dot_product, _MM_SHUFFLE(2, 3, 0, 1)));
+    dot_product = _mm_add_ss(dot_product, _mm_shuffle_ps(dot_product, dot_product, _MM_SHUFFLE(0, 0, 3, 2)));
+
+    // 从target中减去source的方向分量，使其垂直于source
+    __m128 b_orthogonal = _mm_sub_ps(*target, _mm_mul_ps(*source, dot_product));
+
+    // 归一化向量b_orthogonal
+    __m128 b_length_sq = _mm_mul_ps(b_orthogonal, b_orthogonal);
+    b_length_sq = _mm_add_ps(b_length_sq, _mm_shuffle_ps(b_length_sq, b_length_sq, _MM_SHUFFLE(2, 3, 0, 1)));
+    b_length_sq = _mm_add_ss(b_length_sq, _mm_shuffle_ps(b_length_sq, b_length_sq, _MM_SHUFFLE(0, 0, 3, 2)));
+
+    __m128 b_inv_length = _mm_rsqrt_ps(b_length_sq);
+    *target = _mm_mul_ps(b_orthogonal, b_inv_length);
+
+}