src/client/mesh.c

   1 #include <stddef.h>
   2 #include <stdlib.h>
   3 #include "client/mesh.h"
   4
   5 // upload data to GPU (only done once)
   6 void mesh_upload(Mesh *mesh)
   7 {
   8         glGenVertexArrays(1, &mesh->vao);
   9         glGenBuffers(1, &mesh->vbo);
  10
  11         glBindVertexArray(mesh->vao);
  12         glBindBuffer(GL_ARRAY_BUFFER, mesh->vbo);
  13
  14         glBufferData(GL_ARRAY_BUFFER, mesh->count * mesh->layout->size,
  15                 mesh->data, GL_STATIC_DRAW);
  16
  17         size_t offset = 0;
  18         for (GLuint i = 0; i < mesh->layout->count; i++) {
  19                 VertexAttribute *attrib = &mesh->layout->attributes[i];
  20
  21                 glVertexAttribPointer(i, attrib->length, attrib->type, GL_FALSE,
  22                         mesh->layout->size, (GLvoid *) offset);
  23                 glEnableVertexAttribArray(i);
  24
  25                 offset += attrib->size;
  26         }
  27
  28         glBindBuffer(GL_ARRAY_BUFFER, 0);
  29         glBindVertexArray(0);
  30
  31         if (mesh->free_data)
  32                 free(mesh->data);
  33
  34         mesh->data = NULL;
  35 }
  36
  37 void mesh_render(Mesh *mesh)
  38 {
  39         if (mesh->data)
  40                 mesh_upload(mesh);
  41
  42         // render
  43         glBindVertexArray(mesh->vao);
  44         glDrawArrays(GL_TRIANGLES, 0, mesh->count);
  45 }
  46
  47 void mesh_destroy(Mesh *mesh)
  48 {
  49         if (mesh->data && mesh->free_data)
  50                 free(mesh->data);
  51
  52         if (mesh->vao)
  53                 glDeleteVertexArrays(1, &mesh->vao);
  54
  55         if (mesh->vbo)
  56                 glDeleteBuffers(1, &mesh->vbo);
  57
  58         mesh->vao = mesh->vbo = 0;
  59 }