src/graphics/PrimitiveMesh.hpp

   1 #ifndef GONG_GRAPHICS_PRIMITIVEMESH_HPP_
   2 #define GONG_GRAPHICS_PRIMITIVEMESH_HPP_
   3
   4 #include "glm.hpp"
   5 #include "VertexArray.hpp"
   6
   7 #include <vector>
   8 #include <GL/glew.h>
   9
  10
  11 namespace gong {
  12 namespace geometry {
  13         struct AABB;
  14 }
  15 namespace graphics {
  16
  17 class PrimitiveMesh {
  18
  19 public:
  20         using Position = glm::vec3;
  21         using Color = TVEC4<unsigned char, glm::precision(0)>;
  22         using Index = unsigned short;
  23
  24         using Positions = std::vector<Position>;
  25         using Colors = std::vector<Color>;
  26         using Indices = std::vector<Index>;
  27
  28         enum Attribute {
  29                 ATTRIB_VERTEX,
  30                 ATTRIB_COLOR,
  31                 ATTRIB_INDEX,
  32                 ATTRIB_COUNT,
  33         };
  34
  35         struct Buffer {
  36
  37                 Positions vertices;
  38                 Colors colors;
  39                 Indices indices;
  40
  41                 void Clear() noexcept {
  42                         vertices.clear();
  43                         colors.clear();
  44                         indices.clear();
  45                 }
  46
  47                 void Reserve(size_t p, size_t i) {
  48                         vertices.reserve(p);
  49                         colors.reserve(p);
  50                         indices.reserve(i);
  51                 }
  52
  53                 void FillRect(
  54                         float w, float h,
  55                         const Color &color = Color(0),
  56                         const glm::vec2 &pivot = glm::vec2(0.0f)
  57                 );
  58
  59                 void OutlineBox(
  60                         const geometry::AABB &,
  61                         const Color &color = Color(0)
  62                 );
  63
  64         };
  65
  66         using VAO = VertexArray<ATTRIB_COUNT>;
  67
  68 public:
  69         void Update(const Buffer &) noexcept;
  70
  71         bool Empty() const noexcept {
  72                 return vao.Empty();
  73         }
  74
  75         void DrawLines() const noexcept;
  76         void DrawTriangles() const noexcept {
  77                 vao.DrawTriangleElements();
  78         }
  79
  80 private:
  81         VAO vao;
  82
  83 };
  84
  85 }
  86 }
  87
  88 #endif