1 files changed, 200 insertions, 0 deletions
diff --git a/engine-ocean/Game/Components/CollisionComponents/BoundingTriangle.cpp b/engine-ocean/Game/Components/CollisionComponents/BoundingTriangle.cpp
new file mode 100644
index 0000000..519d9c7
--- /dev/null
+++ b/engine-ocean/Game/Components/CollisionComponents/BoundingTriangle.cpp
@@ -0,0 +1,200 @@
+#include "boundingtriangle.h"
+#include "Graphics/global.h"
+#include "Graphics/modeltransform.h"
+#include <iostream>
+#include "glm/gtx/hash.hpp"
+
+// ONLY FOR ENVIRONMENTS
+BoundingTriangle::BoundingTriangle(const std::vector<glm::vec3> &obj_data,
+                                   const std::shared_ptr<ModelTransform> &mt,
+                                   bool isGround) :
+    obj_mt(mt),
+    m_isGround(isGround)
+{
+    populateTriangleData(obj_data);
+    calculateBounds(obj_data);
+    //m_datasize = obj_data.size();
+}
+
+glm::vec3 BoundingTriangle::getRandomSurfacePos(){
+    int randomIndex = std::floor(Global::graphics.generateRandomNumbers(0, m_triangles.size()-1));
+    int randomVertex = std::floor(Global::graphics.generateRandomNumbers(0, 3));
+
+    Triangle randomTri = m_triangles[randomIndex];
+
+    if (glm::dot(glm::vec3(0,1,0), randomTri.normal) > 0.2f){
+        switch(randomVertex){
+            case 0:
+                return randomTri.vertexA;
+            break;
+            case 1:
+                return randomTri.vertexB;
+            break;
+            default:
+                return randomTri.vertexC;
+            break;
+        }
+    } else {
+        // do again until returning a surface triangle
+        getRandomSurfacePos();
+    }
+}
+
+
+void BoundingTriangle::addTriangle(const glm::vec3 &vertexA, const glm::vec3 &vertexB, const glm::vec3 &vertexC){
+    Triangle tri;
+    tri.vertexA = vertexA;
+    tri.vertexB = vertexB;
+    tri.vertexC = vertexC;
+
+    tri.edge1 = vertexB - vertexA; // edge ab
+    tri.edge2 = vertexC - vertexA; // edge bc
+    tri.normal = glm::normalize(glm::cross(tri.edge1, tri.edge2));
+    tri.bounds = calculateTriangleBounds(vertexA, vertexB, vertexC);
+
+    // if triangle is a ground triangle
+    if (m_isGround){
+       if (glm::dot(glm::vec3(0,1,0), tri.normal) > 0.2f){
+           //std::cout << "area: " << getArea(vertexA, vertexB, vertexC) << std::endl;
+           tesselateTriangle(vertexA, vertexB, vertexC);
+       }
+    }
+
+    m_triangles.push_back(tri);
+}
+
+float BoundingTriangle::getArea(const glm::vec3 &A, const glm::vec3 &B, const glm::vec3 &C){
+    glm::vec3 AB = B-A;
+    glm::vec3 AC = C-A;
+    return .5f*glm::length((glm::cross(AB,AC)));
+
+}
+
+glm::vec3 BoundingTriangle::getCentroid(const glm::vec3 &A, const glm::vec3 &B, const glm::vec3 &C){
+    return .333f*(A + B + C);
+}
+
+// tesselation into smaller triangles
+void BoundingTriangle::tesselateTriangle(const glm::vec3 &A, const glm::vec3 &B, const glm::vec3 &C){
+    float min_area = 1.5f;
+
+    // add centroid if area is small enough
+    if (getArea(A,B,C) <= min_area){
+        m_surface_points.push_back(getCentroid(A, B, C));
+        return;
+    }
+
+    // otherwise divide triangle in 4 (tesselate)
+
+        glm::vec3 ab_mid = .5f*(A+B);
+        glm::vec3 ac_mid = .5f*(A+C);
+        glm::vec3 bc_mid = .5f*(B+C);
+        m_surface_points.push_back(ab_mid);
+        m_surface_points.push_back(ac_mid);
+        m_surface_points.push_back(bc_mid);
+
+        tesselateTriangle(ab_mid, ac_mid, A);
+        tesselateTriangle(bc_mid, ab_mid, B);
+        tesselateTriangle(bc_mid, ac_mid, C);
+        tesselateTriangle(ab_mid, ac_mid, bc_mid);
+}
+
+
+void BoundingTriangle::populateTriangleData(const std::vector<glm::vec3> &obj_data){
+    for (int i=0; i<obj_data.size(); i += 3){
+        // convert to worldspace
+        glm::mat4 modelMat = obj_mt->getModelMatrix();
+        glm::vec3 v1 = modelMat*glm::vec4(obj_data[i],1.0);
+        glm::vec3 v2 = modelMat*glm::vec4(obj_data[i+1],1.0);
+        glm::vec3 v3 = modelMat*glm::vec4(obj_data[i+2],1.0);
+
+        // make triangle
+        addTriangle(v1, v2, v3);
+    }
+
+//    m_surface_points.reserve(m_unique_surface_points.size());
+//    std::copy(m_unique_surface_points.begin(), m_unique_surface_points.end(), m_surface_points.begin());
+}
+
+Bounds3f BoundingTriangle::calculateTriangleBounds(const glm::vec3 &vertexA,
+                                                   const glm::vec3 &vertexB,
+                                                   const glm::vec3 &vertexC){
+    Bounds3f bounds;
+
+    float max_x, min_x = vertexA.x;
+    float max_y, min_y = vertexA.y;
+    float max_z, min_z = vertexA.z;
+
+    if (vertexB.x > max_x) max_x = vertexB.x;
+    if (vertexB.y > max_y) max_y = vertexB.y;
+    if (vertexB.z > max_z) max_z = vertexB.z;
+
+    if (vertexC.x > max_x) max_x = vertexC.x;
+    if (vertexC.y > max_y) max_y = vertexC.y;
+    if (vertexC.z > max_z) max_z = vertexC.z;
+
+    if (vertexB.x < min_x) min_x = vertexB.x;
+    if (vertexB.y < min_y) min_y = vertexB.y;
+    if (vertexB.z < min_z) min_z = vertexB.z;
+
+    if (vertexC.x < min_x) min_x = vertexC.x;
+    if (vertexC.y < min_y) min_y = vertexC.y;
+    if (vertexC.z < min_z) min_z = vertexC.z;
+
+
+    bounds.max = glm::vec3(max_x, max_y, max_z);
+    bounds.min = glm::vec3(min_x, min_y, min_z);
+
+    return bounds;
+}
+
+void BoundingTriangle::calculateBounds(const std::vector<glm::vec3> &obj_data){
+    max_x = obj_data[0].x;
+    min_x = obj_data[0].x;
+    max_y = obj_data[0].y;
+    min_y = obj_data[0].y;
+    max_z = obj_data[0].z;
+    min_z = obj_data[0].z;
+
+    for (const glm::vec3 &v : obj_data){
+        // check max
+        if (v.x > max_x){
+            max_x = v.x;
+        }
+        if (v.y > max_y){
+            max_y = v.y;
+        }
+        if (v.z > max_z){
+            max_z = v.z;
+        }
+
+        // check mins
+        if (v.x < min_x){
+            min_x = v.x;
+        }
+        if (v.y < min_y){
+            min_y = v.y;
+        }
+        if (v.z < min_z){
+            min_z = v.z;
+        }
+    }
+}
+
+Bounds3f BoundingTriangle::getMeshBounds(){
+    Bounds3f bounds;
+    bounds.max = glm::vec3(max_x, max_y, max_z);
+    bounds.min = glm::vec3(min_x, min_y, min_z);
+    return bounds;
+}
+
+std::vector<glm::vec3> BoundingTriangle::getSurfacePoints(){
+    if (!m_isGround){
+        std::cout << "getting surface points of not-ground object!" << std::endl;
+    }
+    return m_surface_points;
+}
+
+std::vector<Triangle> BoundingTriangle::getTriangleData(){
+    return m_triangles;
+}