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- #include <stdbool.h>
- #include <spu_intrinsics.h>
- // shuffle helpers
- #define L0 0x00010203
- #define L1 0x04050607
- #define L2 0x08090a0b
- #define L3 0x0c0d0e0f
- #define R0 0x10111213
- #define R1 0x14151617
- #define R2 0x18191a1b
- #define R3 0x1c1d1e1f
- #define ZERO 0x80808080
- #define SHUFFLE(l, r, x, y, z, w) si_shufb(l, r, ((qword)(vec_uint4){x, y, z, w}))
- // splat helper
- #define SPLAT(v, idx) si_shufb(v, v, (qword)(vec_uint4)(L ## idx))
- struct matrix_t
- {
- vec_float4 row0;
- vec_float4 row1;
- vec_float4 row2;
- vec_float4 row3;
- };
- struct aabb_t
- {
- vec_float4 min;
- vec_float4 max;
- };
- static inline void transform_points_4(qword* dest, qword x, qword y, qword z, const struct matrix_t* mat)
- {
- #define COMP(c) \
- qword res_ ## c = SPLAT((qword)mat->row3, c); \
- res_ ## c = si_fma(z, SPLAT((qword)mat->row2, c), res_ ## c); \
- res_ ## c = si_fma(y, SPLAT((qword)mat->row1, c), res_ ## c); \
- res_ ## c = si_fma(x, SPLAT((qword)mat->row0, c), res_ ## c); \
- dest[c] = res_ ## c;
- COMP(0);
- COMP(1);
- COMP(2);
- COMP(3);
- #undef COMP
- }
- static inline void transform_matrix(struct matrix_t* dest, const struct matrix_t* lhs, const struct matrix_t* rhs)
- {
- #define COMP_0(c) \
- qword res_ ## c = si_fm((qword)lhs->row2, SPLAT((qword)rhs->row ## c, 2)); \
- res_ ## c = si_fma((qword)lhs->row1, SPLAT((qword)rhs->row ## c, 1), res_ ## c); \
- res_ ## c = si_fma((qword)lhs->row0, SPLAT((qword)rhs->row ## c, 0), res_ ## c); \
- dest->row ## c = (vec_float4)res_ ## c;
- #define COMP_1(c) \
- qword res_ ## c = si_fma((qword)lhs->row2, SPLAT((qword)rhs->row ## c, 2), (qword)lhs->row3); \
- res_ ## c = si_fma((qword)lhs->row1, SPLAT((qword)rhs->row ## c, 1), res_ ## c); \
- res_ ## c = si_fma((qword)lhs->row0, SPLAT((qword)rhs->row ## c, 0), res_ ## c); \
- dest->row ## c = (vec_float4)res_ ## c;
- COMP_0(0);
- COMP_0(1);
- COMP_0(2);
- COMP_1(3);
- #undef COMP_0
- #undef COMP_1
- }
- __attribute__((noinline)) unsigned int is_visible(const struct matrix_t* transform, const struct aabb_t* aabb, const struct matrix_t* frustum)
- {
- qword min = (qword)aabb->min;
- qword max = (qword)aabb->max;
- // get aabb points (SoA)
- qword minmax_x = SHUFFLE(min, max, L0, R0, L0, R0); // x X x X
- qword minmax_y = SHUFFLE(min, max, L1, L1, R1, R1); // y y Y Y
- qword minmax_z_0 = SPLAT(min, 2); // z z z z
- qword minmax_z_1 = SPLAT(max, 2); // Z Z Z Z
- // get clipping matrix
- struct matrix_t clip;
- transform_matrix(&clip, frustum, transform);
- // transform points to clip space
- qword points_cs_0[4];
- qword points_cs_1[4];
- transform_points_4(points_cs_0, minmax_x, minmax_y, minmax_z_0, &clip);
- transform_points_4(points_cs_1, minmax_x, minmax_y, minmax_z_1, &clip);
- // calculate -w
- qword points_cs_0_negw = si_xor(points_cs_0[3], (qword)(vec_uint4)(0x80000000));
- qword points_cs_1_negw = si_xor(points_cs_1[3], (qword)(vec_uint4)(0x80000000));
- // for each plane...
- #define NOUT(a, b, c, d) si_orx(si_or(si_fcgt(a, b), si_fcgt(c, d)))
- qword nout0 = NOUT(points_cs_0[0], points_cs_0_negw, points_cs_1[0], points_cs_1_negw);
- qword nout1 = NOUT(points_cs_0[3], points_cs_0[0], points_cs_1[3], points_cs_1[0]);
- qword nout2 = NOUT(points_cs_0[1], points_cs_0_negw, points_cs_1[1], points_cs_1_negw);
- qword nout3 = NOUT(points_cs_0[3], points_cs_0[1], points_cs_1[3], points_cs_1[1]);
- qword nout4 = NOUT(points_cs_0[2], (qword)(0), points_cs_1[2], (qword)(0));
- qword nout5 = NOUT(points_cs_0[3], points_cs_0[2], points_cs_1[3], points_cs_1[2]);
- #undef NOUT
- // merge "not outside" flags
- qword nout01 = si_and(nout0, nout1);
- qword nout012 = si_and(nout01, nout2);
- qword nout34 = si_and(nout3, nout4);
- qword nout345 = si_and(nout34, nout5);
- qword nout = si_and(nout012, nout345);
- return si_to_uint(nout);
- }
- // simple ortho frustum
- struct matrix_t frustum =
- {
- { 0.1f, 0, 0, 0 },
- { 0, 0.1f, 0, 0 },
- { 0, 0, 0.1f, 0 },
- { 0, 0, 0, 1 }
- };
- // small box
- struct aabb_t aabb =
- {
- { -1, -2, -3 },
- { 1, 2, 3 }
- };
- // and some weird matrix
- struct matrix_t transform =
- {
- { 0.123f, 0.456f, 0.789f },
- { 0.456f, 0.123f, 0.789f },
- { 0.789f, 0.123f, 0.456f },
- { 1.f, -1.f, 1.f }
- };
- int main()
- {
- is_visible(&transform, &aabb, &frustum);
- si_stop(0);
- }
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