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 = 2 },
  36    .fbdepth   = { .format = GL_RGBA, .div = 2 }
  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    v3f volume;
  82    v3_sub( bounds[1], bounds[0], volume );
  83    box_copy( bounds, wrender.depthbounds );
  84
  85    for( int y=0; y<kres; y++ )
  86    {
  87       for( int x=0; x<kres; x++ )
  88       {
  89          v3f pos = { x, 0, y };
  90          v3_divs( pos, kres, pos );
  91          v3_muladd( bounds[0], pos, volume, pos );
  92          pos[1] = wrender.height;
  93
  94          ray_hit hit;
  95          hit.dist = INFINITY;
  96          u8 *dst = &img[ y*kres+x ];
  97
  98          if( ray_world( pos, (v3f){0.0f,-1.0f,0.0f}, &hit ))
  99          {
 100             float h = wrender.height - hit.pos[1];
 101             h *= 1.0f/15.0f;
 102             h = vg_clampf( h, 0.0f, 1.0f );
 103             *dst = (u8)(h*255.0f);
 104          }
 105          else
 106             *dst = 0;
 107       }
 108    }
 109
 110    if( wrender.depth_computed )
 111       glDeleteTextures( 1, &wrender.depthmap );
 112
 113    glGenTextures( 1, &wrender.depthmap );
 114    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
 115    glTexImage2D( GL_TEXTURE_2D, 0, GL_RED, kres, kres, 0,
 116          GL_RED, GL_UNSIGNED_BYTE, img );
 117
 118    vg_tex2d_mipmap();
 119    vg_tex2d_linear_mipmap();
 120    vg_tex2d_clamp();
 121
 122    wrender.depth_computed = 1;
 123    free( img );
 124    vg_success( "Done.\n" );
 125 }
 126
 127 static void water_set_surface( glmesh *surf, float height )
 128 {
 129    wrender.mdl = *surf;
 130    wrender.height = height;
 131 }
 132
 133 static void render_water_texture( m4x3f camera )
 134 {
 135    if( !wrender.enabled )
 136       return;
 137
 138    /* Draw reflection buffa */
 139    fb_use( &wrender.fbreflect );
 140    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 141
 142    m4x3f new_cam, inverse;
 143    v3_copy( camera[3], new_cam[3] );
 144    new_cam[3][1] -= 2.0f * (camera[3][1] - wrender.height);
 145
 146    m3x3f flip;
 147    m3x3_identity( flip );
 148    flip[1][1] = -1.0f;
 149    m3x3_mul( flip, camera, new_cam );
 150
 151
 152    v3f p0;
 153    m3x3_mulv( new_cam, (v3f){0.0f,0.0f,-1.0f}, p0 );
 154    v3_add( new_cam[3], p0, p0 );
 155    vg_line( new_cam[3], p0, 0xffffffff );
 156
 157    m4x4f view;
 158    vg_line_pt3( new_cam[3], 0.3f, 0xff00ffff );
 159
 160    m4x3_invert_affine( new_cam, inverse );
 161    m4x3_expand( inverse, view );
 162
 163    v4f clippa = { 0.0f, 1.0f, 0.0f, wrender.height-0.1f };
 164    m4x3_mulp( inverse, clippa, clippa );
 165    clippa[3] *= -1.0f;
 166
 167    m4x4f projection;
 168    m4x4_projection( projection,
 169          gpipeline.fov,
 170          (float)vg_window_x / (float)vg_window_y,
 171          0.1f, 900.0f );
 172    plane_clip_projection( projection, clippa );
 173    m4x4_mul( projection, view, projection );
 174
 175    glCullFace( GL_FRONT );
 176    render_world( projection, new_cam );
 177    glCullFace( GL_BACK );
 178
 179
 180    /* Draw beneath texture */
 181    fb_use( &wrender.fbdepth );
 182    glClear( GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT );
 183
 184    m4x3_invert_affine( camera, inverse );
 185    m4x3_expand( inverse, view );
 186
 187    v4f clippb = { 0.0f, -1.0f, 0.0f, -(wrender.height) };
 188    m4x3_mulp( inverse, clippb, clippb );
 189    clippb[3] *= -1.0f;
 190
 191    float depth_loss = camera[3][1]-wrender.height;
 192
 193    m4x4_projection( projection,
 194          gpipeline.fov,
 195          (float)vg_window_x / (float)vg_window_y,
 196          0.1f, 900.0f );
 197
 198    plane_clip_projection( projection, clippb );
 199    m4x4_mul( projection, view, projection );
 200    render_world( projection, camera );
 201
 202    glViewport( 0, 0, vg_window_x, vg_window_y );
 203 }
 204
 205 static void render_water_surface( m4x4f pv, m4x3f camera )
 206 {
 207    if( !wrender.enabled )
 208       return;
 209
 210    /* Draw surface */
 211    shader_water_use();
 212
 213    fb_bindtex( &wrender.fbreflect, 0 );
 214    shader_water_uTexMain( 0 );
 215
 216    vg_tex2d_bind( &tex_water_surf, 1 );
 217    shader_water_uTexDudv( 1 );
 218    shader_water_uInvRes( (v2f){
 219          1.0f / (float)vg_window_x,
 220          1.0f / (float)vg_window_y });
 221
 222    glActiveTexture( GL_TEXTURE2 );
 223    glBindTexture( GL_TEXTURE_2D, wrender.depthmap );
 224    shader_water_uTexDepth( 2 );
 225    shader_water_uDepthBounds( (v4f){
 226          wrender.depthbounds[0][0],
 227          wrender.depthbounds[0][2],
 228          1.0f/ (wrender.depthbounds[1][0]-wrender.depthbounds[0][0]),
 229          1.0f/ (wrender.depthbounds[1][2]-wrender.depthbounds[0][2])} );
 230
 231    fb_bindtex( &wrender.fbdepth, 3 );
 232    shader_water_uTexBack( 3 );
 233
 234    shader_water_uTime( vg_time );
 235    shader_water_uCamera( camera[3] );
 236    shader_water_uSurfaceY( wrender.height );
 237
 238    shader_water_uPv( pv );
 239
 240    m4x3f full;
 241    m4x3_identity( full );
 242    full[3][1] = wrender.height;
 243
 244    shader_water_uMdl( full );
 245
 246    glEnable(GL_BLEND);
 247    glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
 248    glBlendEquation(GL_FUNC_ADD);
 249
 250    mesh_bind( &wrender.mdl );
 251    mesh_draw( &wrender.mdl );
 252
 253    glDisable(GL_BLEND);
 254 }
 255
 256 #endif /* WATER_H */