From bf39fef7eed69e6d5ecfa272607cbf0fcc53b9a6 Mon Sep 17 00:00:00 2001 From: vimene Date: Sat, 9 Dec 2023 06:33:39 +0100 Subject: fixed perspective calculations --- src/o3d/tri_deriv_vertex.cpp | 321 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 321 insertions(+) create mode 100644 src/o3d/tri_deriv_vertex.cpp (limited to 'src/o3d/tri_deriv_vertex.cpp') diff --git a/src/o3d/tri_deriv_vertex.cpp b/src/o3d/tri_deriv_vertex.cpp new file mode 100644 index 0000000..3605b51 --- /dev/null +++ b/src/o3d/tri_deriv_vertex.cpp @@ -0,0 +1,321 @@ +#include "o3d/tri_deriv_vertex.h" +#include +#include "math/vector.h" +#include "o3d/deriv_vertex.h" + +using namespace engine::o3d; + +TriangleDerivedVertex4::TriangleDerivedVertex4(DerivedVertex4 derived_vertex1, DerivedVertex4 derived_vertex2, DerivedVertex4 derived_vertex3) + : derived_vertex1{derived_vertex1}, derived_vertex2{derived_vertex2}, derived_vertex3{derived_vertex3} { +} + +#define P1_OUT 1 +#define P2_OUT 2 +#define P3_OUT 4 +static void _perspective_crop_x(std::vector& tris, TriangleDerivedVertex4 t, int n, float x) { + switch (n) { + case 0: + tris.push_back(t); + break; + case P1_OUT: + case P2_OUT: + case P3_OUT: + case P2_OUT | P3_OUT: + case P1_OUT | P3_OUT: + case P1_OUT | P2_OUT: + { + DerivedVertex4* q1; + DerivedVertex4* q2; + DerivedVertex4* q3; + switch (n) { + case P1_OUT: + case P2_OUT | P3_OUT: + q1 = &t.derived_vertex1; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex3; + break; + case P2_OUT: + case P1_OUT | P3_OUT: + q1 = &t.derived_vertex2; + q2 = &t.derived_vertex1; + q3 = &t.derived_vertex3; + break; + case P3_OUT: + case P1_OUT | P2_OUT: + q1 = &t.derived_vertex3; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex1; + break; + } + engine::math::Vector4 dq2 = q1->point - q2->point; + float fac2 = (x - q2->point.x) / dq2.x; + float r2w = 1.f / (fac2 / q1->point.w + (1.f - fac2) / q2->point.w); + float fac2_b = r2w * fac2 / q1->point.w; + DerivedVertex4 r2{ + { + x, + q2->point.y + fac2 * dq2.y, + fac2_b * q1->point.z + (1.f - fac2_b) * q2->point.z, + r2w + }, + fac2_b * q1->b0 + (1.f - fac2_b) * q2->b0, + fac2_b * q1->b1 + (1.f - fac2_b) * q2->b1 + }; + engine::math::Vector4 dq3 = q1->point - q3->point; + float fac3 = (x - q3->point.x) / dq3.x; + float r3w = 1.f / (fac3 / q1->point.w + (1.f - fac3) / q3->point.w); + float fac3_b = r3w * fac3 / q1->point.w; + DerivedVertex4 r3{ + { + x, + q3->point.y + fac3 * dq3.y, + fac3_b * q1->point.z + (1.f - fac3_b) * q3->point.z, + r3w + }, + fac3_b * q1->b0 + (1.f - fac3_b) * q3->b0, + fac3_b * q1->b1 + (1.f - fac3_b) * q3->b1 + }; + switch (n) { + case P1_OUT: + tris.push_back({r3, *q2, *q3}); + tris.push_back({r3, r2, *q2}); + break; + case P2_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P3_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P2_OUT | P3_OUT: + tris.push_back({*q1, r2, r3}); + break; + case P1_OUT | P3_OUT: + tris.push_back({*q1, r3, r2}); + break; + case P1_OUT | P2_OUT: + tris.push_back({*q1, r3, r2}); + break; + } + } + break; + case P1_OUT | P2_OUT | P3_OUT: + break; + } +} + +static void _perspective_crop_y(std::vector& tris, TriangleDerivedVertex4 t, int n, float y) { + switch (n) { + case 0: + tris.push_back(t); + break; + case P1_OUT: + case P2_OUT: + case P3_OUT: + case P2_OUT | P3_OUT: + case P1_OUT | P3_OUT: + case P1_OUT | P2_OUT: + { + DerivedVertex4* q1; + DerivedVertex4* q2; + DerivedVertex4* q3; + switch (n) { + case P1_OUT: + case P2_OUT | P3_OUT: + q1 = &t.derived_vertex1; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex3; + break; + case P2_OUT: + case P1_OUT | P3_OUT: + q1 = &t.derived_vertex2; + q2 = &t.derived_vertex1; + q3 = &t.derived_vertex3; + break; + case P3_OUT: + case P1_OUT | P2_OUT: + q1 = &t.derived_vertex3; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex1; + break; + } + engine::math::Vector4 dq2 = q1->point - q2->point; + float fac2 = (y - q2->point.y) / dq2.y; + float r2w = 1.f / (fac2 / q1->point.w + (1.f - fac2) / q2->point.w); + float fac2_b = r2w * fac2 / q1->point.w; + DerivedVertex4 r2{ + { + q2->point.x + fac2 * dq2.x, + y, + fac2_b * q1->point.z + (1.f - fac2_b) * q2->point.z, + r2w + }, + fac2_b * q1->b0 + (1.f - fac2_b) * q2->b0, + fac2_b * q1->b1 + (1.f - fac2_b) * q2->b1 + }; + engine::math::Vector4 dq3 = q1->point - q3->point; + float fac3 = (y - q3->point.y) / dq3.y; + float r3w = 1.f / (fac3 / q1->point.w + (1.f - fac3) / q3->point.w); + float fac3_b = r3w * fac3 / q1->point.w; + DerivedVertex4 r3{ + { + q3->point.x + fac3 * dq3.x, + y, + fac3_b * q1->point.z + (1.f - fac3_b) * q3->point.z, + r3w + }, + fac3_b * q1->b0 + (1.f - fac3_b) * q3->b0, + fac3_b * q1->b1 + (1.f - fac3_b) * q3->b1 + }; + switch (n) { + case P1_OUT: + tris.push_back({r3, *q2, *q3}); + tris.push_back({r3, r2, *q2}); + break; + case P2_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P3_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P2_OUT | P3_OUT: + tris.push_back({*q1, r2, r3}); + break; + case P1_OUT | P3_OUT: + tris.push_back({*q1, r3, r2}); + break; + case P1_OUT | P2_OUT: + tris.push_back({*q1, r3, r2}); + break; + } + } + break; + case P1_OUT | P2_OUT | P3_OUT: + break; + } +} + +std::vector TriangleDerivedVertex4::perspective_crop_xy_out(float x1, float x2, float y1, float y2) const { + std::vector tris_final; + std::vector tris1; + _perspective_crop_x(tris1, *this, (derived_vertex1.point.x < x1) | ((derived_vertex2.point.x < x1) << 1) | ((derived_vertex3.point.x < x1) << 2), x1); + for (auto t1 : tris1) { + std::vector tris2; + _perspective_crop_x(tris2, t1, (t1.derived_vertex1.point.x > x2) | ((t1.derived_vertex2.point.x > x2) << 1) | ((t1.derived_vertex3.point.x > x2) << 2), x2); + for (auto t2 : tris2) { + std::vector tris3; + _perspective_crop_y(tris3, t2, (t2.derived_vertex1.point.y < y1) | ((t2.derived_vertex2.point.y < y1) << 1) | ((t2.derived_vertex3.point.y < y1) << 2), y1); + for (auto t3 : tris3) + _perspective_crop_y(tris_final, t3, (t3.derived_vertex1.point.y > y2) | ((t3.derived_vertex2.point.y > y2) << 1) | ((t3.derived_vertex3.point.y > y2) << 2), y2); + } + } + return tris_final; +} + +static void _crop_z(std::vector& tris, TriangleDerivedVertex4 t, int n, float z) { + switch (n) { + case 0: + tris.push_back(t); + break; + case P1_OUT: + case P2_OUT: + case P3_OUT: + case P2_OUT | P3_OUT: + case P1_OUT | P3_OUT: + case P1_OUT | P2_OUT: + { + DerivedVertex4* q1; + DerivedVertex4* q2; + DerivedVertex4* q3; + switch (n) { + case P1_OUT: + case P2_OUT | P3_OUT: + q1 = &t.derived_vertex1; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex3; + break; + case P2_OUT: + case P1_OUT | P3_OUT: + q1 = &t.derived_vertex2; + q2 = &t.derived_vertex1; + q3 = &t.derived_vertex3; + break; + case P3_OUT: + case P1_OUT | P2_OUT: + q1 = &t.derived_vertex3; + q2 = &t.derived_vertex2; + q3 = &t.derived_vertex1; + break; + } + engine::math::Vector4 dq2 = q1->point - q2->point; + float fac2 = (z - q2->point.z) / dq2.z; + DerivedVertex4 r2{ + { + q2->point.x + fac2 * dq2.x, + q2->point.y + fac2 * dq2.y, + z, + q2->point.w + fac2 * dq2.w + }, + fac2 * q1->b0 + (1.f - fac2) * q2->b0, + fac2 * q1->b1 + (1.f - fac2) * q2->b1 + }; + engine::math::Vector4 dq3 = q1->point - q3->point; + float fac3 = (z - q3->point.z) / dq3.z; + DerivedVertex4 r3{ + { + q3->point.x + fac3 * dq3.x, + q3->point.y + fac3 * dq3.y, + z, + q3->point.w + fac3 * dq3.w + }, + fac3 * q1->b0 + (1.f - fac3) * q3->b0, + fac3 * q1->b1 + (1.f - fac3) * q3->b1 + }; + switch (n) { + case P1_OUT: + tris.push_back({r3, *q2, *q3}); + tris.push_back({r3, r2, *q2}); + break; + case P2_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P3_OUT: + tris.push_back({r2, *q3, *q2}); + tris.push_back({r2, r3, *q3}); + break; + case P2_OUT | P3_OUT: + tris.push_back({*q1, r2, r3}); + break; + case P1_OUT | P3_OUT: + tris.push_back({*q1, r3, r2}); + break; + case P1_OUT | P2_OUT: + tris.push_back({*q1, r3, r2}); + break; + } + } + break; + case P1_OUT | P2_OUT | P3_OUT: + break; + } +} + +std::vector TriangleDerivedVertex4::crop_z_out(float z1, float z2) const { + std::vector tris; + _crop_z(tris, *this, (derived_vertex1.point.z < z1) | ((derived_vertex2.point.z < z1) << 1) | ((derived_vertex3.point.z < z1) << 2), z1); + std::vector tris2; + for (auto t : tris) + _crop_z(tris2, t, (t.derived_vertex1.point.z > z2) | ((t.derived_vertex2.point.z > z2) << 1) | ((t.derived_vertex3.point.z > z2) << 2), z2); + return tris2; +} +#undef P1_OUT +#undef P2_OUT +#undef P3_OUT + +TriangleDerivedVertex4 TriangleDerivedVertex4::div_by_w() const { + return {derived_vertex1.div_by_w(), derived_vertex2.div_by_w(), derived_vertex3.div_by_w()}; +} -- cgit v1.2.3