vg_rigidbody_view.h

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