vg_rigidbody_view.c

   1 #pragma once
   2 #include "vg_platform.h"
   3 #include "vg_rigidbody.h"
   4 #include "vg_shader.h"
   5 #include "vg_engine.h"
   6 #include "vg_async.h"
   7
   8 static struct vg_shader _shader_rigidbody =
   9 {
  10    .name = "[vg] rigidbody",
  11    .vs = {
  12       .orig_file = NULL,
  13       .static_src =
  14
  15         "uniform mat4 uPv;"
  16    "uniform mat4x3 uMdl;"
  17    "uniform mat4x3 uMdl1;"
  18         "layout (location=0) in vec4 a_co;"
  19         "layout (location=1) in vec3 a_norm;"
  20    "out vec3 aNorm;"
  21    "out vec3 aCo;"
  22         ""
  23         "void main()"
  24         "{"
  25       "vec3 world_pos0 = uMdl  * vec4( a_co.xyz, 1.0 );"
  26       "vec3 world_pos1 = uMdl1 * vec4( a_co.xyz, 1.0 );"
  27       "vec3 co = mix( world_pos0, world_pos1, a_co.w );"
  28            "vec4 vert_pos = uPv * vec4( co, 1.0 );"
  29
  30            "gl_Position = vert_pos;"
  31       "vec3 l = vec3(length(uMdl[0]),length(uMdl[1]),length(uMdl[2]));"
  32       "aNorm = (mat3(uMdl) * a_norm)/l;"
  33       "aCo = a_co.xyz*l;"
  34         "}"
  35    },
  36    .fs = {
  37       .orig_file = NULL,
  38       .static_src =
  39
  40         "out vec4 FragColor;"
  41    "uniform vec4 uColour;"
  42         ""
  43    "in vec3 aNorm;"
  44    "in vec3 aCo;"
  45    // The MIT License
  46    // Copyright © 2017 Inigo Quilez
  47    // Permission is hereby granted, free of charge, to any person obtaining a
  48    // copy of this software and associated documentation files (the "Software"),
  49    // to deal in the Software without restriction, including without limitation
  50    // the rights to use, copy, modify, merge, publish, distribute, sublicense,
  51    // and/or sell copies of the Software, and to permit persons to whom the
  52    // Software is furnished to do so, subject to the following conditions:
  53    // The above copyright notice and this permission notice shall be included in
  54    // all copies or substantial portions of the Software. THE SOFTWARE IS
  55    // PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  56    // INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
  57    // FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  58    // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  59    // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  60    // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  61    // DEALINGS IN THE SOFTWARE.
  62
  63    // Info: https://iquilezles.org/articles/filterableprocedurals
  64    //
  65    // More filtered patterns:  https://www.shadertoy.com/playlist/l3KXR1
  66
  67    "vec3 tri( in vec3 x ){"
  68       "return 1.0-abs(2.0*fract(x/2.0)-1.0);"
  69    "}"
  70
  71    "float checkersTextureGrad( in vec3 p, in vec3 ddx, in vec3 ddy ){"
  72      "vec3 w = max(abs(ddx), abs(ddy)) + 0.0001;" // filter kernel
  73      "vec3 i = (tri(p+0.5*w)-tri(p-0.5*w))/w;"    // analytical integral
  74                                                   //    (box filter)
  75      "return 0.5 - 0.5*i.x*i.y*i.z;"              // xor pattern
  76    "}"
  77         ""
  78         "void main()"
  79         "{"
  80       "vec3 uvw = aCo;"
  81       "vec3 ddx_uvw = dFdx( uvw );"
  82       "vec3 ddy_uvw = dFdy( uvw );"
  83       "float diffuse = checkersTextureGrad( uvw, ddx_uvw, ddy_uvw )*0.5+0.4;"
  84       "float light = dot( vec3(0.8017,0.5345,-0.2672), aNorm )*0.5 + 0.5;"
  85            "FragColor = light * diffuse * uColour;"
  86         "}"
  87    }
  88 };
  89
  90 #pragma pack(push,1)
  91 struct rb_view_vert {
  92    v4f co;
  93    v3f n;
  94 };
  95 #pragma pack(pop)
  96
  97 typedef struct rb_view_vert rb_view_vert;
  98
  99 struct {
 100    GLuint vao, vbo, ebo;
 101    u32 sphere_start, sphere_count,
 102        box_start, box_count;
 103 }
 104 static vg_rb_view;
 105
 106 struct vg_rb_mesh_init {
 107    u32 verts_size, tris_size;
 108    rb_view_vert *verts;
 109    u16 *tris;
 110 };
 111
 112 static void async_vg_rb_view_init( void *payload, u32 payload_size )
 113 {
 114    struct vg_rb_mesh_init *inf = payload;
 115
 116    glGenVertexArrays( 1, &vg_rb_view.vao );
 117    glGenBuffers( 1, &vg_rb_view.vbo );
 118    glGenBuffers( 1, &vg_rb_view.ebo );
 119    glBindVertexArray( vg_rb_view.vao );
 120
 121
 122    glBindBuffer( GL_ARRAY_BUFFER, vg_rb_view.vbo );
 123    glBufferData( GL_ARRAY_BUFFER, inf->verts_size, inf->verts, GL_STATIC_DRAW );
 124    glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, vg_rb_view.ebo );
 125    glBufferData( GL_ELEMENT_ARRAY_BUFFER,
 126                   inf->tris_size, inf->tris, GL_STATIC_DRAW );
 127
 128    /* 0: coordinates */
 129    size_t stride = sizeof(rb_view_vert);
 130    glVertexAttribPointer( 0, 4, GL_FLOAT, GL_FALSE, stride, (void*)0 );
 131    glEnableVertexAttribArray( 0 );
 132
 133    /* 1: normal */
 134    glVertexAttribPointer( 1, 3, GL_FLOAT, GL_FALSE,
 135                           stride, (void *)offsetof(rb_view_vert, n) );
 136    glEnableVertexAttribArray( 1 );
 137
 138    VG_CHECK_GL_ERR();
 139 }
 140
 141 void vg_rb_view_init(void)
 142 {
 143    vg_shader_register( &_shader_rigidbody );
 144
 145    u32 H = 20,
 146        V = 16,
 147        verts_count = 0,
 148        tris_count = 0;
 149
 150    /* box */
 151    verts_count += 4*6;
 152    tris_count += 2*6;
 153    vg_rb_view.box_count = 2*6;
 154    vg_rb_view.box_start = 0;
 155
 156    /* sphere */
 157    verts_count += H*(V-2) + 2;
 158    tris_count  += H*2 + (V-2)*(H*2);
 159    vg_rb_view.sphere_count = H*2 + (V-2)*(H*2);
 160
 161    u32 hdr_size  = vg_align8( sizeof(struct vg_rb_mesh_init) ),
 162        vert_size = vg_align8( verts_count * sizeof(rb_view_vert) ),
 163        tris_size = vg_align8( tris_count * 3 * sizeof(u16) );
 164
 165    vg_async_item *call = vg_async_alloc( hdr_size + vert_size + tris_size );
 166
 167    struct vg_rb_mesh_init *inf = call->payload;
 168    rb_view_vert *verts = ((void *)inf) + hdr_size;
 169    u16 *tris = ((void *)inf) + hdr_size + vert_size;
 170
 171    inf->verts = verts;
 172    inf->tris = tris;
 173    inf->verts_size = vert_size;
 174    inf->tris_size = tris_size;
 175
 176    u32 tri_index = 0,
 177        vert_index = 0;
 178
 179    /* box
 180     * ----------------------------------------------------------- */
 181    for( u32 i=0; i<6; i ++ ){
 182       v3f n = {i%3==0,i%3==1,i%3==2};
 183       if( i >= 3 ) v3_negate( n, n );
 184       v3f v0, v1;
 185       v3_tangent_basis( n, v0, v1 );
 186
 187       rb_view_vert *vs = &verts[vert_index];
 188       vert_index += 4;
 189
 190       for( u32 j=0; j<4; j ++ ){
 191          v3_copy( n, vs[j].n );
 192          v3_muladds( n, v0, j&0x1?1.0f:-1.0f, vs[j].co );
 193          v3_muladds( vs[j].co, v1, j&0x2?1.0f:-1.0f, vs[j].co );
 194          vs[j].co[3] = 0.0f;
 195       }
 196
 197       tris[tri_index*3+0] = i*4+0;
 198       tris[tri_index*3+1] = i*4+1;
 199       tris[tri_index*3+2] = i*4+3;
 200       tris[tri_index*3+3] = i*4+0;
 201       tris[tri_index*3+4] = i*4+3;
 202       tris[tri_index*3+5] = i*4+2;
 203       tri_index += 2;
 204    }
 205
 206    /* sphere / capsule
 207     * ----------------------------------------------------------- */
 208    u32 base = vert_index;
 209    vg_rb_view.sphere_start = tri_index;
 210    v4_copy( (v4f){0,-1,0,0}, verts[vert_index].co );
 211    v3_copy( (v3f){0,-1,0}, verts[vert_index ++].n );
 212
 213    for( u32 x=0; x<H; x ++ ){
 214       tris[tri_index*3+0] = base+0;
 215       tris[tri_index*3+1] = base+1+x;
 216       tris[tri_index*3+2] = base+1+((x+1)%H);
 217       tri_index += 1;
 218    }
 219
 220    for( u32 y=1; y<V-1; y ++ ){
 221       f32 ty = ((f32)y/(f32)(V-1)) * VG_PIf;
 222       u32 ybase = y-1;
 223       for( u32 x=0; x<H; x ++ ){
 224          f32 tx = ((f32)x/(f32)H) * VG_TAUf;
 225
 226          v4f co = { cosf(tx)*sinf(ty), -cosf(ty), sinf(tx)*sinf(ty), y>=(V/2) };
 227          v4_copy( co, verts[vert_index].co );
 228          v4_copy( co, verts[vert_index ++].n );
 229
 230          if( y < V-2 ){
 231             tris[tri_index*3+0] = base+1 + ybase*H + x;
 232             tris[tri_index*3+1] = base+1 + (ybase+1)*H + ((x+1)%H);
 233             tris[tri_index*3+2] = base+1 + ybase*H + ((x+1)%H);
 234             tris[tri_index*3+3] = base+1 + ybase*H + x;
 235             tris[tri_index*3+4] = base+1 + (ybase+1)*H + x;
 236             tris[tri_index*3+5] = base+1 + (ybase+1)*H + ((x+1)%H);
 237             tri_index += 2;
 238          }
 239       }
 240    }
 241
 242    v4_copy( (v4f){0, 1,0,1}, verts[vert_index].co );
 243    v3_copy( (v3f){0, 1,0}, verts[vert_index ++].n );
 244
 245    for( u32 x=0; x<H; x ++ ){
 246       tris[tri_index*3+0] = base + (H*(V-2) + 2)-1;
 247       tris[tri_index*3+1] = base+1 + (V-3)*H+((x+1)%H);
 248       tris[tri_index*3+2] = base+1 + (V-3)*H+x;
 249       tri_index += 1;
 250    }
 251
 252    vg_async_dispatch( call, async_vg_rb_view_init );
 253 }
 254
 255 void vg_rb_view_bind(void)
 256 {
 257    glEnable( GL_CULL_FACE );
 258    glEnable( GL_DEPTH_TEST );
 259
 260         glUseProgram( _shader_rigidbody.id );
 261    glUniformMatrix4fv( glGetUniformLocation( _shader_rigidbody.id, "uPv" ),
 262      1, GL_FALSE, (float *)vg.pv );
 263
 264         glBindVertexArray( vg_rb_view.vao );
 265 }
 266
 267 void vg_rb_view_box( m4x3f mdl, boxf bbx, v4f colour )
 268 {
 269    v3f e;
 270    v3_sub( bbx[1], bbx[0], e );
 271    v3_muls( e, 0.5f, e );
 272
 273    m4x3f mmdl;
 274    m4x3_identity( mmdl );
 275    m3x3_scale( mmdl, e );
 276    v3_add( bbx[0], e, mmdl[3] );
 277    m4x3_mul( mdl, mmdl, mmdl );
 278
 279    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl" ),
 280                          1,GL_FALSE,(float*)mmdl);
 281    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl1" ),
 282                          1,GL_FALSE,(float*)mmdl);
 283    glUniform4fv( glGetUniformLocation( _shader_rigidbody.id, "uColour" ), 1,
 284                  colour );
 285         glDrawElements( GL_TRIANGLES,
 286                    vg_rb_view.box_count*3, GL_UNSIGNED_SHORT,
 287                    (void *)(vg_rb_view.box_start*3*sizeof(u16)) );
 288 }
 289
 290 void vg_rb_view_sphere( m4x3f mdl, f32 r, v4f colour )
 291 {
 292    m4x3f mmdl;
 293    m4x3_copy( mdl, mmdl );
 294    m3x3_scalef( mmdl, r );
 295    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl" ),
 296                          1,GL_FALSE,(float*)mmdl);
 297    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl1" ),
 298                          1,GL_FALSE,(float*)mmdl);
 299    glUniform4fv( glGetUniformLocation( _shader_rigidbody.id, "uColour" ), 1,
 300                  colour );
 301         glDrawElements( GL_TRIANGLES,
 302                    vg_rb_view.sphere_count*3, GL_UNSIGNED_SHORT,
 303                    (void *)(vg_rb_view.sphere_start*3*sizeof(u16)) );
 304 }
 305
 306 void vg_rb_view_capsule( m4x3f mdl, f32 r, f32 h, v4f colour )
 307 {
 308    m4x3f mmdl0, mmdl1;
 309    m4x3_identity( mmdl0 );
 310    m4x3_identity( mmdl1 );
 311    m3x3_scalef( mmdl0, r );
 312    m3x3_scalef( mmdl1, r );
 313    mmdl0[3][1] = -h*0.5f+r;
 314    mmdl1[3][1] =  h*0.5f-r;
 315    m4x3_mul( mdl, mmdl0, mmdl0 );
 316    m4x3_mul( mdl, mmdl1, mmdl1 );
 317
 318    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl" ),
 319                          1,GL_FALSE,(float*)mmdl0);
 320    glUniformMatrix4x3fv( glGetUniformLocation( _shader_rigidbody.id, "uMdl1" ),
 321                          1,GL_FALSE,(float*)mmdl1);
 322    glUniform4fv( glGetUniformLocation( _shader_rigidbody.id, "uColour" ), 1,
 323                  colour );
 324         glDrawElements( GL_TRIANGLES,
 325                    vg_rb_view.sphere_count*3, GL_UNSIGNED_SHORT,
 326                    (void *)(vg_rb_view.sphere_start*3*sizeof(u16)) );
 327 }