water.h

   1 #include "common.h"
   2 #include "model.h"
   3
   4 static void water_register(void);
   5 static void water_init(void);
   6 static void water_fb_resize(void);
   7 static void water_compute_depth( boxf bounds );
   8 static void water_set_surface( glmesh *surf, float height );
   9 static float water_height(void);
  10
  11 #ifndef WATER_H
  12 #define WATER_H
  13
  14 #include "world.h"
  15 #include "render.h"
  16 #include "shaders/water.h"
  17 #include "scene.h"
  18
  19 vg_tex2d tex_water_surf = { .path = "textures/water_surf.qoi" };
  20
  21 static struct
  22 {
  23    struct framebuffer fbreflect, fbdepth;
  24    glmesh mdl;
  25
  26    GLuint depthmap;
  27    boxf depthbounds;
  28    int depth_computed;
  29
  30    float height;
  31    int enabled;
  32 }
  33 wrender =
  34 {
  35    .fbreflect = { .format = GL_RGB,  .div = 3 },
  36    .fbdepth   = { .format = GL_RGBA, .div = 4 }
  37 };
  38
  39 static float water_height(void)
  40 {
  41    return wrender.height;
  42 }
  43
  44 static void water_register(void)
  45 {
  46    shader_water_register();
  47 }
  48
  49 static void water_init(void)
  50 {
  51    /* TODO: probably dont do this every time */
  52    wrender.enabled = 1;
  53
  54    fb_init( &wrender.fbreflect );
  55    fb_init( &wrender.fbdepth );
  56 }
  57
  58 static void water_fb_resize(void)
  59 {
  60    if( !wrender.enabled )
  61       return;
  62
  63    fb_resize( &wrender.fbreflect );
  64    fb_resize( &wrender.fbdepth );
  65 }
  66
  67 static void water_compute_depth( boxf bounds )
  68 {
  69    if( !wrender.enabled )
  70       return;
  71
  72 #ifdef VG_RELEASE
  73    int const kres = 512;
  74 #else
  75    int const kres = 64;
  76 #endif
  77
  78    vg_info( "Computing depth map\n" );
  79    u8 *img = malloc( kres*kres );
  80
  81    boxf interior;
  82    v3_add(bounds[0],(v3f){1.0f,1.0f,1.0f},interior[0]);
  83    v3_sub(bounds[1],(v3f){1.0f,1.0f,1.0f},interior[1]);
  84
  85    v3f volume;
  86    v3_sub( interior[1], interior[0], volume );
  87    box_copy( interior, wrender.depthbounds );
  88
  89    for( int y=0; y<kres; y++ )
  90    {
  91       for( int x=0; x<kres; x++ )
  92       {
  93          v3f pos = { x, 0.0f, y };
  94          pos[0] += 0.5f;
  95          pos[1] += 0.5f;
  96          v3_divs( pos, kres+1, pos );
  97          v3_muladd( interior[0], pos, volume, pos );
  98          pos[1] = 2000.0f;
  99
 100          ray_hit hit;
 101          hit.dist = INFINITY;
 102          u8 *dst = &img[ y*kres+x ];
 103
 104          if( ray_world( pos, (v3f){0.0f,-1.0f,0.0f}, &hit ))
 105          {
 106             float h = wrender.height - hit.pos[1];
 107             h *= 1.0f/25.0f;
 108             h = vg_clampf( h, 0.0f, 1.0f );
 109             *dst = (u8)(h*255.0f);
 110          }
 111          else
 112          {
 113             *dst = 0;
 114          }
 115       }
 116    }
 117
 118    if( wrender.depth_computed )
 119       glDeleteTextures( 1, &wrender.depthmap );
 120
 121    glGenTextures( 1, &wrender.depthmap );
 122    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
 123    glTexImage2D( GL_TEXTURE_2D, 0, GL_RED, kres, kres, 0,
 124          GL_RED, GL_UNSIGNED_BYTE, img );
 125
 126    vg_tex2d_mipmap();
 127    vg_tex2d_linear_mipmap();
 128    vg_tex2d_clamp();
 129
 130    wrender.depth_computed = 1;
 131    free( img );
 132    vg_success( "Done.\n" );
 133 }
 134
 135 static void water_set_surface( glmesh *surf, float height )
 136 {
 137    wrender.mdl = *surf;
 138    wrender.height = height;
 139 }
 140
 141 static void render_water_texture( m4x3f camera )
 142 {
 143    if( !wrender.enabled )
 144       return;
 145
 146    /* Draw reflection buffa */
 147    fb_use( &wrender.fbreflect );
 148    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 149
 150    m4x3f new_cam, inverse;
 151    v3_copy( camera[3], new_cam[3] );
 152    new_cam[3][1] -= 2.0f * (camera[3][1] - wrender.height);
 153
 154    m3x3f flip;
 155    m3x3_identity( flip );
 156    flip[1][1] = -1.0f;
 157    m3x3_mul( flip, camera, new_cam );
 158
 159
 160    v3f p0;
 161    m3x3_mulv( new_cam, (v3f){0.0f,0.0f,-1.0f}, p0 );
 162    v3_add( new_cam[3], p0, p0 );
 163    vg_line( new_cam[3], p0, 0xffffffff );
 164
 165    m4x4f view;
 166    vg_line_pt3( new_cam[3], 0.3f, 0xff00ffff );
 167
 168    m4x3_invert_affine( new_cam, inverse );
 169    m4x3_expand( inverse, view );
 170
 171    v4f clippa = { 0.0f, 1.0f, 0.0f, wrender.height-0.1f };
 172    m4x3_mulp( inverse, clippa, clippa );
 173    clippa[3] *= -1.0f;
 174
 175    m4x4f projection;
 176    m4x4_projection( projection,
 177          gpipeline.fov,
 178          (float)vg_window_x / (float)vg_window_y,
 179          0.1f, 900.0f );
 180    plane_clip_projection( projection, clippa );
 181    m4x4_mul( projection, view, projection );
 182
 183    glCullFace( GL_FRONT );
 184    render_world( projection, new_cam );
 185    glCullFace( GL_BACK );
 186
 187
 188    /* Draw beneath texture */
 189    fb_use( &wrender.fbdepth );
 190    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 191
 192    m4x3_invert_affine( camera, inverse );
 193    m4x3_expand( inverse, view );
 194
 195    float bias = -(camera[3][1]-wrender.height)*0.1f;
 196    v4f clippb = { 0.0f, -1.0f, 0.0f, -(wrender.height) + bias };
 197    m4x3_mulp( inverse, clippb, clippb );
 198    clippb[3] *= -1.0f;
 199
 200    m4x4_projection( projection,
 201          gpipeline.fov,
 202          (float)vg_window_x / (float)vg_window_y,
 203          0.1f, 900.0f );
 204
 205    plane_clip_projection( projection, clippb );
 206    m4x4_mul( projection, view, projection );
 207    render_world( projection, camera );
 208
 209    glViewport( 0, 0, vg_window_x, vg_window_y );
 210 }
 211
 212 static void render_water_surface( m4x4f pv, m4x3f camera )
 213 {
 214    if( !wrender.enabled )
 215       return;
 216
 217    /* Draw surface */
 218    shader_water_use();
 219
 220    fb_bindtex( &wrender.fbreflect, 0 );
 221    shader_water_uTexMain( 0 );
 222
 223    vg_tex2d_bind( &tex_water_surf, 1 );
 224    shader_water_uTexDudv( 1 );
 225    shader_water_uInvRes( (v2f){
 226          1.0f / (float)vg_window_x,
 227          1.0f / (float)vg_window_y });
 228
 229    glActiveTexture( GL_TEXTURE2 );
 230    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
 231    shader_water_uTexDepth( 2 );
 232    shader_water_uDepthBounds( (v4f){
 233          wrender.depthbounds[0][0],
 234          wrender.depthbounds[0][2],
 235          1.0f/ (wrender.depthbounds[1][0]-wrender.depthbounds[0][0]),
 236          1.0f/ (wrender.depthbounds[1][2]-wrender.depthbounds[0][2])} );
 237
 238    fb_bindtex( &wrender.fbdepth, 3 );
 239    shader_water_uTexBack( 3 );
 240
 241    shader_water_uTime( vg_time );
 242    shader_water_uCamera( camera[3] );
 243    shader_water_uSurfaceY( wrender.height );
 244
 245    shader_water_uPv( pv );
 246
 247    m4x3f full;
 248    m4x3_identity( full );
 249    full[3][1] = wrender.height;
 250
 251    shader_water_uMdl( full );
 252
 253    glEnable(GL_BLEND);
 254    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 255    glBlendEquation(GL_FUNC_ADD);
 256
 257    mesh_bind( &wrender.mdl );
 258    mesh_draw( &wrender.mdl );
 259
 260    glDisable(GL_BLEND);
 261 }
 262
 263 #endif /* WATER_H */