pointcloud.h

   1 #ifndef POINTCLOUD_H
   2 #define POINTCLOUD_H
   3
   4 #include "common.h"
   5 #include "world.h"
   6 #include "shaders/point_map.h"
   7
   8 #define POINTCLOUD_POINTS 250000
   9
  10 struct pointcloud{
  11    GLuint vao, vbo;
  12    u32 count;
  13    v4f control;
  14 }
  15 static pointcloud = { .control = {0.0f,0.0f,0.0f,1.0f} };
  16
  17 #pragma pack(push,1)
  18 struct pointcloud_vert{
  19    i16 pos[4];    /* float[ -1 -> 1 ] */
  20    u8  colour[4]; /* float[  0 -> 1 ] */
  21 };
  22 #pragma pack(pop)
  23
  24 typedef struct pointcloud_vert pointcloud_vert;
  25 typedef struct pointcloud_buffer pointcloud_buffer;
  26
  27 struct pointcloud_buffer{
  28    u32 max, count;
  29    boxf boundary;
  30
  31    enum pointcloud_op{
  32       k_pointcloud_op_clear,
  33       k_pointcloud_op_append
  34    }
  35    op;
  36    pointcloud_vert buf[];
  37 };
  38
  39 static void async_pointcloud_sub( void *payload, u32 size )
  40 {
  41    glBindVertexArray( pointcloud.vao );
  42    glBindBuffer( GL_ARRAY_BUFFER, pointcloud.vbo );
  43
  44    pointcloud_buffer *buf = payload;
  45
  46    u32 start,end,count;
  47    if( buf->op == k_pointcloud_op_append ){
  48       start = pointcloud.count;
  49       end = pointcloud.count + buf->count;
  50    }
  51    else{
  52       start = 0;
  53       end = buf->count;
  54    }
  55
  56    end = VG_MIN(POINTCLOUD_POINTS,end);
  57    count = end-start;
  58
  59    if( count ){
  60       u32 size   = count * sizeof(pointcloud_vert),
  61           offset = start * sizeof(pointcloud_vert);
  62
  63       glBufferSubData( GL_ARRAY_BUFFER, offset, size, buf->buf );
  64       pointcloud.count = end;
  65    }
  66 }
  67
  68 static void async_pointcloud_alloc( void *payload, u32 size )
  69 {
  70    glGenVertexArrays( 1, &pointcloud.vao );
  71    glGenBuffers( 1, &pointcloud.vbo );
  72    glBindVertexArray( pointcloud.vao );
  73
  74    size_t stride = sizeof( pointcloud_vert );
  75
  76    glBindBuffer( GL_ARRAY_BUFFER, pointcloud.vbo );
  77    glBufferData( GL_ARRAY_BUFFER, stride * POINTCLOUD_POINTS,
  78                  NULL, GL_DYNAMIC_DRAW );
  79
  80    /* 0: coordinates */
  81    glVertexAttribPointer( 0, 4, GL_SHORT, GL_TRUE, stride, (void*)0 );
  82    glEnableVertexAttribArray( 0 );
  83
  84    /* 1: colour */
  85    glVertexAttribPointer( 1, 4, GL_UNSIGNED_BYTE, GL_TRUE,
  86                      stride, (void *)offsetof(pointcloud_vert, colour) );
  87    glEnableVertexAttribArray( 1 );
  88    VG_CHECK_GL_ERR();
  89 }
  90
  91 static void pointcloud_init(void)
  92 {
  93    vg_async_call( async_pointcloud_alloc, NULL, 0 );
  94    shader_point_map_register();
  95 }
  96
  97 static void pointcloud_render( world_instance *world, camera *cam, m4x3f model )
  98 {
  99    m4x4f upvmprev;
 100    m4x3_expand( model, upvmprev );
 101    m4x4_mul( cam->mtx_prev.pv, upvmprev, upvmprev );
 102
 103    shader_point_map_use();
 104    shader_point_map_uPv( cam->mtx.pv );
 105    shader_point_map_uPvmPrev( upvmprev );
 106    shader_point_map_uMdl( model );
 107    shader_point_map_uCamera( cam->pos );
 108    shader_point_map_uTime( (v2f){ vg.time, sinf(vg.time) } );
 109    shader_point_map_uTransform( pointcloud.control );
 110
 111    glBindVertexArray( pointcloud.vao );
 112    glEnable( GL_PROGRAM_POINT_SIZE );
 113    glDrawArrays( GL_POINTS, 0, pointcloud.count );
 114 }
 115
 116 #endif /* POINTCLOUD_H */