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