water.h

   1 #ifndef WATER_H
   2 #define WATER_H
   3
   4 #define VG_3D
   5 #include "vg/vg.h"
   6
   7 #include "model.h"
   8 #include "render.h"
   9 #include "shaders/water.h"
  10 #include "scene.h"
  11
  12 vg_tex2d tex_water_surf = { .path = "textures/water_surf.qoi" };
  13
  14 static struct
  15 {
  16    GLuint fb, rgb, rb;
  17    glmesh mdl;
  18
  19    GLuint depthmap;
  20    boxf depthbounds;
  21    int depth_computed;
  22
  23    float height;
  24    int enabled;
  25 }
  26 wrender;
  27
  28 static void water_register(void)
  29 {
  30    shader_water_register();
  31 }
  32
  33 static void water_init(void)
  34 {
  35    /* TODO: probably dont do this every time */
  36    create_renderbuffer_std( &wrender.fb, &wrender.rgb, &wrender.rb );
  37    wrender.enabled = 1;
  38 }
  39
  40 static int ray_world( v3f pos, v3f dir, ray_hit *hit );
  41 static void water_compute_depth( boxf bounds )
  42 {
  43    if( !wrender.enabled )
  44       return;
  45
  46 #ifdef VG_RELEASE
  47    int const kres = 512;
  48 #else
  49    int const kres = 64;
  50 #endif
  51
  52    vg_info( "Computing depth map\n" );
  53    u8 *img = malloc( kres*kres );
  54
  55    v3f volume;
  56    v3_sub( bounds[1], bounds[0], volume );
  57    box_copy( bounds, wrender.depthbounds );
  58
  59    for( int y=0; y<kres; y++ )
  60    {
  61       for( int x=0; x<kres; x++ )
  62       {
  63          v3f pos = { x, 0, y };
  64          v3_divs( pos, kres, pos );
  65          v3_muladd( bounds[0], pos, volume, pos );
  66          pos[1] = wrender.height;
  67
  68          ray_hit hit;
  69          hit.dist = INFINITY;
  70          u8 *dst = &img[ y*kres+x ];
  71
  72          if( ray_world( pos, (v3f){0.0f,-1.0f,0.0f}, &hit ))
  73          {
  74             float h = wrender.height - hit.pos[1];
  75             h *= 1.0f/15.0f;
  76             h = vg_clampf( h, 0.0f, 1.0f );
  77             *dst = (u8)(h*255.0f);
  78          }
  79          else
  80             *dst = 0;
  81       }
  82    }
  83
  84    if( wrender.depth_computed )
  85       glDeleteTextures( 1, &wrender.depthmap );
  86
  87    glGenTextures( 1, &wrender.depthmap );
  88    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
  89    glTexImage2D( GL_TEXTURE_2D, 0, GL_RED, kres, kres, 0,
  90          GL_RED, GL_UNSIGNED_BYTE, img );
  91
  92    vg_tex2d_mipmap();
  93    vg_tex2d_linear_mipmap();
  94    vg_tex2d_clamp();
  95
  96    wrender.depth_computed = 1;
  97    free( img );
  98    vg_success( "Done.\n" );
  99 }
 100
 101 static void water_set_surface( glmesh *surf, float height )
 102 {
 103    wrender.mdl = *surf;
 104    wrender.height = height;
 105 }
 106
 107 static void water_fb_resize(void)
 108 {
 109    if( !wrender.enabled )
 110       return;
 111
 112    resize_renderbuffer_std( &wrender.fb, &wrender.rgb, &wrender.rb );
 113 }
 114
 115 static void render_water_texture( m4x3f camera )
 116 {
 117    if( !wrender.enabled )
 118       return;
 119
 120    /* Draw reflection buffa */
 121    glBindFramebuffer( GL_FRAMEBUFFER, wrender.fb );
 122    glClearColor( 0.11f, 0.35f, 0.37f, 1.0f );
 123    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 124
 125    m4x3f new_cam, inverse;
 126    v3_copy( camera[3], new_cam[3] );
 127    new_cam[3][1] -= 2.0f * (camera[3][1] - wrender.height);
 128
 129    m3x3f flip;
 130    m3x3_identity( flip );
 131    flip[1][1] = -1.0f;
 132    m3x3_mul( flip, camera, new_cam );
 133
 134
 135    v3f p0;
 136    m3x3_mulv( new_cam, (v3f){0.0f,0.0f,-1.0f}, p0 );
 137    v3_add( new_cam[3], p0, p0 );
 138    vg_line( new_cam[3], p0, 0xffffffff );
 139
 140    m4x4f view;
 141    vg_line_pt3( new_cam[3], 0.3f, 0xff00ffff );
 142
 143    m4x3_invert_affine( new_cam, inverse );
 144    m4x3_expand( inverse, view );
 145
 146    v4f clippa = { 0.0f, 1.0f, 0.0f, wrender.height-0.1f };
 147    m4x3_mulp( inverse, clippa, clippa );
 148    clippa[3] *= -1.0f;
 149
 150    m4x4f projection;
 151    m4x4_projection( projection,
 152          gpipeline.fov,
 153          (float)vg_window_x / (float)vg_window_y,
 154          0.1f, 900.0f );
 155    plane_clip_projection( projection, clippa );
 156    m4x4_mul( projection, view, projection );
 157
 158    glCullFace( GL_FRONT );
 159    render_world( projection, new_cam );
 160    glCullFace( GL_BACK );
 161 }
 162
 163 static void render_water_surface( m4x4f pv )
 164 {
 165    if( !wrender.enabled )
 166       return;
 167
 168    /* Draw surface */
 169    shader_water_use();
 170
 171    glActiveTexture( GL_TEXTURE0 );
 172    glBindTexture( GL_TEXTURE_2D, wrender.rgb );
 173    shader_water_uTexMain( 0 );
 174
 175    vg_tex2d_bind( &tex_water_surf, 1 );
 176    shader_water_uTexDudv( 1 );
 177    shader_water_uInvRes( (v2f){
 178          1.0f / (float)vg_window_x,
 179          1.0f / (float)vg_window_y });
 180
 181    glActiveTexture( GL_TEXTURE2 );
 182    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
 183    shader_water_uTexDepth( 2 );
 184    shader_water_uDepthBounds( (v4f){
 185          wrender.depthbounds[0][0],
 186          wrender.depthbounds[0][2],
 187          1.0f/ (wrender.depthbounds[1][0]-wrender.depthbounds[0][0]),
 188          1.0f/ (wrender.depthbounds[1][2]-wrender.depthbounds[0][2])} );
 189
 190    shader_water_uTime( vg_time );
 191    shader_water_uPv( pv );
 192
 193    m4x3f full;
 194    m4x3_identity( full );
 195    full[3][1] = wrender.height;
 196
 197    shader_water_uMdl( full );
 198
 199    glEnable(GL_BLEND);
 200    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 201    glBlendEquation(GL_FUNC_ADD);
 202
 203    mesh_bind( &wrender.mdl );
 204    mesh_draw( &wrender.mdl );
 205
 206    glDisable(GL_BLEND);
 207 }
 208
 209 #endif /* WATER_H */