Starting work on capsules.

src/dawn/display/mesh/CMakeLists.txt

@@ -6,6 +6,7 @@
 # Sources
 target_sources(${DAWN_TARGET_NAME}
   PRIVATE
+    CapsuleMesh.cpp
     CubeMesh.cpp
     TriangleMesh.cpp
     QuadMesh.cpp

src/dawn/display/mesh/CapsuleMesh.cpp

@@ -0,0 +1,99 @@
+// Copyright (c) 2023 Dominic Masters
+// 
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+#include "CapsuleMesh.hpp"
+
+using namespace Dawn;
+
+void CapsuleMesh::calculateRing(
+  int32_t segments,
+  float_t height,
+  float_t radius,
+  float_t dr,
+  float_t y,
+  float_t dy,
+  std::vector<glm::vec3> *positions
+) {
+  assertNotNull(positions);
+  float_t segIncr = 1.0f / (float_t)(segments - 1);
+  for(int32_t s = 0; s < segments; s++ ) {
+    float_t x = cosf(MATH_PI * 2 * s * segIncr) * dr;
+    float_t z = sinf(MATH_PI * 2 * s * segIncr) * dr;
+    positions->emplace_back(glm::vec3(radius * x, radius * y + height * dy, radius * z ));
+  }
+}
+
+void CapsuleMesh::create(
+  Mesh *mesh,
+  float_t radius,
+  float_t height
+) {
+  assertNotNull(mesh);
+
+  std::vector<glm::vec3> positions;
+  std::vector<meshindice_t> indices;
+
+  int32_t slices = 12;
+  int32_t segments = 12;
+  int32_t ringsBody = slices + 1;
+  int32_t ringsTotal = slices + ringsBody;
+
+  positions.reserve(segments * ringsTotal);
+  indices.reserve((segments - 1) * (ringsTotal - 1) * 6);
+
+  float_t bodyIncr = 1.0f / (float_t)(ringsBody - 1);
+  float_t ringIncr = 1.0f / (float_t)(slices - 1);
+  for(int32_t r = 0; r < slices / 2; r++) {
+    calculateRing(
+      segments,
+      height,
+      radius,
+      sinf(MATH_PI * r * ringIncr),
+      sinf(MATH_PI * (r * ringIncr - 0.5f)),
+      -0.5f,
+      &positions
+    );
+  }
+
+  for(int32_t r = 0; r < ringsBody; r++ ) {
+    calculateRing(
+      segments,
+      height,
+      radius,
+      1.0f,
+      0.0f,
+      r * bodyIncr - 0.5f,
+      &positions
+    );
+  }
+
+  for(int32_t r = slices / 2; r < slices; r++) {
+    calculateRing(
+      segments,
+      height,
+      radius,
+      sinf(MATH_PI * r * ringIncr),
+      sinf(MATH_PI * (r * ringIncr - 0.5f)),
+      0.5f,
+      &positions
+    );
+  }
+
+  for(int32_t r = 0; r < ringsTotal - 1; r++ ) {
+    for(int32_t s = 0; s < segments - 1; s++ ) {
+      indices.push_back( (uint32_t)(r * segments + ( s + 1 )) );
+      indices.push_back( (uint32_t)(r * segments + ( s + 0 )) );
+      indices.push_back( (uint32_t)(( r + 1 ) * segments + ( s + 1 )) );
+
+      indices.push_back( (uint32_t)(( r + 1 ) * segments + ( s + 0 )) );
+      indices.push_back( (uint32_t)(( r + 1 ) * segments + ( s + 1 )) );
+      indices.push_back( (uint32_t)(r * segments + s) );
+    }
+  }
+
+  mesh->createBuffers(positions.size(), indices.size());
+  mesh->bufferPositions(0, positions.data(), positions.size());
+  mesh->bufferIndices(0, indices.data(), indices.size());
+}

src/dawn/display/mesh/CapsuleMesh.hpp

@@ -0,0 +1,30 @@
+// Copyright (c) 2023 Dominic Masters
+// 
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+#pragma once
+#include "display/mesh/Mesh.hpp"
+#include "util/mathutils.hpp"
+
+namespace Dawn {
+  class CapsuleMesh {
+    protected:
+      static void calculateRing(
+        int32_t segments,
+        float_t height,
+        float_t radius,
+        float_t dr,
+        float_t y,
+        float_t dy,
+        std::vector<glm::vec3> *positions
+      );
+
+    public:
+      static void create(
+        Mesh *mesh,
+        float_t radius,
+        float_t height
+      );
+  };
+}