Add collision culling for Underworld

This should perhaps be handled by a game subsystem that does collision culling in the future, but adds some FPS in big levels for now

src/cdc/math/Vector.cpp

@@ -1,5 +1,7 @@
 #include "Vector.h"
 
+#include <math.h>
+
 void cdc::Vector::operator +=(Vector* b)
 {
 	vec128 = _mm_add_ps(vec128, b->vec128);
@@ -28,4 +30,13 @@ void cdc::Vector::operator *=(float b)
 void cdc::Vector::operator /=(float b)
 {
 	vec128 = _mm_div_ps(vec128, _mm_shuffle_ps(_mm_set_ss(b), _mm_set_ss(b), _MM_SHUFFLE(0, 0, 0, 0)));
+}
+
+float cdc::Vector::operator -(cdc::Vector* b)
+{
+	// https://stackoverflow.com/a/2264878/9398242
+	auto diff = _mm_sub_ps(vec128, b->vec128);
+	auto sqr = _mm_mul_ps(diff, diff);
+
+	return sqrtf(sqr.m128_f32[0] + sqr.m128_f32[1] + sqr.m128_f32[2]);
 }

src/cdc/math/Vector.h

@@ -27,6 +27,8 @@ namespace cdc
 
 		void operator *=(float b);
 		void operator /=(float b);
+
+		float operator -(cdc::Vector* b);
 	};
 
 	class Vector2 : public Vector

src/modules/Draw.cpp

@@ -151,6 +151,10 @@ void Draw::OnDraw()
 			ImGui::Checkbox("Player collision", &m_drawPlayerCollision);
 			ImGui::Checkbox("Enemy collision", &m_drawEnemyCollision);
 
+#ifdef TR8
+			ImGui::Checkbox("Cull close collision", &m_cull);
+#endif
+
 			ImGui::InputInt("Terrain group", &m_terrainGroup);
 		}
 
@@ -385,6 +389,7 @@ void Draw::DrawCollision(Level* level)
 void Draw::DrawCollision(TerrainGroup* terrainGroup, int flags)
 {
 	auto mesh = terrainGroup->mesh;
+	auto player = Game::GetPlayerInstance();
 
 	// Draw all mesh faces
 	for (int i = 0; i < mesh->m_numFaces; i++)
@@ -396,6 +401,13 @@ void Draw::DrawCollision(TerrainGroup* terrainGroup, int flags)
 		auto y = GetVertice(face->i1, mesh, &mesh->m_position);
 		auto z = GetVertice(face->i2, mesh, &mesh->m_position);
 
+#ifdef TR8
+		if (m_cull && (!player || (player->position - &x) > kCollisionFar))
+		{
+			continue;
+		}
+#endif
+
 		// Draw the face
 		auto color = flags & kEnemyCollision ? RGBA(255, 0, 255, 10) : RGBA(0, 255, 0, 10);
 		DrawTriangle(&x, &y, &z, color);

src/modules/Draw.h

@@ -28,6 +28,7 @@ class Draw : public Module
 	// Collision options
 	bool m_drawPlayerCollision = true;
 	bool m_drawEnemyCollision = true;
+	bool m_cull = true;
 
 	int m_terrainGroup = -1;
 
@@ -53,4 +54,6 @@ class Draw : public Module
 constexpr auto kEnemyCollision = 0x4000;
 #else
 constexpr auto kEnemyCollision = 0x800;
-#endif
+#endif
+
+constexpr auto kCollisionFar = 20000;

src/render/DrawBatcher.cpp

@@ -4,7 +4,7 @@ DrawBatcher* DrawBatcher::s_batcher = nullptr;
 
 DrawBatcher::DrawBatcher() : m_vertices()
 {
-	m_vertices.reserve(0x2000);
+	m_vertices.reserve(0x4000);
 }
 
 void DrawBatcher::DrawTriangles(DRAWVERTEX* verts, int numtris) noexcept

tests/TestMath.cpp

@@ -0,0 +1,16 @@
+#include <catch_amalgamated.hpp>
+#include <math.h>
+
+#include "cdc/math/Vector.h"
+
+TEST_CASE("vector3")
+{
+	SECTION("can calculate distance")
+	{
+		auto first  = cdc::Vector3{ 100.f, 11.f, 300.f };
+		auto second = cdc::Vector3{ 400.f, 10.f, 230.f };
+		auto distance = first - &second;
+
+		REQUIRE(floor(distance) == 308);
+	}
+}