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
  14    f64 anim_start;
  15    f32 visibility;
  16    enum pointcloud_anim{
  17       k_pointcloud_anim_opening = 0,
  18       k_pointcloud_anim_hiding  = 1,
  19       k_pointcloud_anim_idle    = 2
  20    }
  21    anim;
  22 }
  23 static pointcloud;
  24
  25 #pragma pack(push,1)
  26 struct pointcloud_vert{
  27    i16 pos[4];    /* float[ -1 -> 1 ] */
  28    u8  colour[4]; /* float[  0 -> 1 ] */
  29 };
  30 #pragma pack(pop)
  31
  32 typedef struct pointcloud_vert pointcloud_vert;
  33 typedef struct pointcloud_buffer pointcloud_buffer;
  34
  35 struct pointcloud_buffer{
  36    u32 max, count;
  37    boxf boundary;
  38
  39    enum pointcloud_op{
  40       k_pointcloud_op_clear,
  41       k_pointcloud_op_append
  42    }
  43    op;
  44    pointcloud_vert buf[];
  45 };
  46
  47 static void async_pointcloud_sub( void *payload, u32 size )
  48 {
  49    glBindVertexArray( pointcloud.vao );
  50    glBindBuffer( GL_ARRAY_BUFFER, pointcloud.vbo );
  51
  52    pointcloud_buffer *buf = payload;
  53
  54    u32 start,end,count;
  55    if( buf->op == k_pointcloud_op_append ){
  56       start = pointcloud.count;
  57       end = pointcloud.count + buf->count;
  58    }
  59    else{
  60       start = 0;
  61       end = buf->count;
  62    }
  63
  64    end = VG_MIN(POINTCLOUD_POINTS,end);
  65    count = end-start;
  66
  67    if( count ){
  68       u32 size   = count * sizeof(pointcloud_vert),
  69           offset = start * sizeof(pointcloud_vert);
  70
  71       glBufferSubData( GL_ARRAY_BUFFER, offset, size, buf->buf );
  72       pointcloud.count = end;
  73    }
  74 }
  75
  76 static void async_pointcloud_alloc( void *payload, u32 size )
  77 {
  78    glGenVertexArrays( 1, &pointcloud.vao );
  79    glGenBuffers( 1, &pointcloud.vbo );
  80    glBindVertexArray( pointcloud.vao );
  81
  82    size_t stride = sizeof( pointcloud_vert );
  83
  84    glBindBuffer( GL_ARRAY_BUFFER, pointcloud.vbo );
  85    glBufferData( GL_ARRAY_BUFFER, stride * POINTCLOUD_POINTS,
  86                  NULL, GL_DYNAMIC_DRAW );
  87
  88    /* 0: coordinates */
  89    glVertexAttribPointer( 0, 4, GL_SHORT, GL_TRUE, stride, (void*)0 );
  90    glEnableVertexAttribArray( 0 );
  91
  92    /* 1: colour */
  93    glVertexAttribPointer( 1, 4, GL_UNSIGNED_BYTE, GL_TRUE,
  94                      stride, (void *)offsetof(pointcloud_vert, colour) );
  95    glEnableVertexAttribArray( 1 );
  96    VG_CHECK_GL_ERR();
  97 }
  98
  99 static void pointcloud_init(void)
 100 {
 101    vg_async_call( async_pointcloud_alloc, NULL, 0 );
 102    shader_point_map_register();
 103 }
 104
 105 static void pointcloud_render( world_instance *world, camera *cam, m4x3f model )
 106 {
 107    if( pointcloud.anim != k_pointcloud_anim_idle ){
 108       f32 const k_transition = 1.0f;
 109       f32 t = (vg.time - pointcloud.anim_start) / k_transition;
 110
 111       if( pointcloud.anim == k_pointcloud_anim_hiding ){
 112          if( t > 1.0f ){
 113             pointcloud.visibility = 0.0f;
 114             pointcloud.anim = k_pointcloud_anim_idle;
 115          }
 116          else pointcloud.visibility = 1.0f-t;
 117       }
 118       else if( pointcloud.anim == k_pointcloud_anim_opening ){
 119          if( t > 1.0f ){
 120             pointcloud.visibility = 1.0f;
 121             pointcloud.anim = k_pointcloud_anim_idle;
 122          }
 123          else pointcloud.visibility = t;
 124       }
 125    }
 126
 127    if( pointcloud.visibility == 0.0f ) return;
 128
 129    m4x4f upvmprev;
 130    m4x3_expand( model, upvmprev );
 131    m4x4_mul( cam->mtx_prev.pv, upvmprev, upvmprev );
 132
 133    shader_point_map_use();
 134    shader_point_map_uPv( cam->mtx.pv );
 135    shader_point_map_uPvmPrev( upvmprev );
 136    shader_point_map_uMdl( model );
 137    shader_point_map_uCamera( cam->pos );
 138    shader_point_map_uAnim( (v4f){ 32, 1.0f-pointcloud.visibility,
 139                                   0.0f, vg.time } );
 140
 141    glBindVertexArray( pointcloud.vao );
 142    glEnable( GL_PROGRAM_POINT_SIZE );
 143    glDrawArrays( GL_POINTS, 0, pointcloud.count );
 144 }
 145
 146 #endif /* POINTCLOUD_H */