src/graphics/SpriteMesh.hpp

   1 #ifndef GONG_GRPAHICS_SPRITEMESH_HPP_
   2 #define GONG_GRPAHICS_SPRITEMESH_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 graphics {
  13
  14 class SpriteMesh {
  15
  16 public:
  17         using Position = glm::vec3;
  18         using TexCoord = glm::vec2;
  19         using Index = unsigned short;
  20
  21         using Positions = std::vector<Position>;
  22         using TexCoords = std::vector<TexCoord>;
  23         using Indices = std::vector<Index>;
  24
  25         enum Attribute {
  26                 ATTRIB_VERTEX,
  27                 ATTRIB_TEXCOORD,
  28                 ATTRIB_INDEX,
  29                 ATTRIB_COUNT,
  30         };
  31
  32         struct Buffer {
  33
  34                 Positions vertices;
  35                 TexCoords coords;
  36                 Indices indices;
  37
  38                 void Clear() noexcept {
  39                         vertices.clear();
  40                         coords.clear();
  41                         indices.clear();
  42                 }
  43
  44                 void Reserve(size_t p, size_t i) {
  45                         vertices.reserve(p);
  46                         coords.reserve(p);
  47                         indices.reserve(i);
  48                 }
  49
  50                 void LoadRect(
  51                         float w, float h,
  52                         const glm::vec2 &pivot = glm::vec2(0.0f),
  53                         const glm::vec2 &tex_begin = glm::vec2(0.0f),
  54                         const glm::vec2 &tex_end = glm::vec2(1.0f, 1.0f)
  55                 );
  56
  57         };
  58
  59         using VAO = VertexArray<ATTRIB_COUNT>;
  60
  61 public:
  62         void Update(const Buffer &) noexcept;
  63
  64         bool Empty() const noexcept {
  65                 return vao.Empty();
  66         }
  67
  68         void Draw() const noexcept {
  69                 vao.DrawTriangleElements();
  70         }
  71
  72 private:
  73         VAO vao;
  74
  75 };
  76
  77 }
  78 }
  79
  80 #endif