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