vg_lines.c

   1 /* Copyright (C) 2021-2024 Harry Godden (hgn) - All Rights Reserved */
   2
   3 #pragma once
   4 #include "vg_lines.h"
   5 #include "vg_shader.h"
   6 #include "vg_engine.h"
   7 #include "vg_async.h"
   8
   9 struct vg_lines vg_lines;
  10
  11 /*
  12  * FIXME: The line buffer sometimes overflows. Low priority
  13  */
  14
  15 static struct vg_shader _shader_lines = {
  16    .name = "[vg] lines",
  17    .vs = {
  18       .orig_file = NULL,
  19       .static_src =
  20
  21         "uniform mat4 uPv;"
  22         "layout (location=0) in vec3 a_co;"
  23         "layout (location=1) in vec4 a_colour;"
  24         ""
  25         "out vec4 s_colour;"
  26         ""
  27         "void main()"
  28         "{"
  29         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  30         "  s_colour = a_colour;"
  31         "       gl_Position = vert_pos;"
  32         "}"
  33    },
  34    .fs = {
  35       .orig_file = NULL,
  36       .static_src =
  37
  38         "out vec4 FragColor;"
  39         ""
  40         "in vec4 s_colour;"
  41         ""
  42         "void main()"
  43         "{"
  44         "       FragColor = s_colour;"
  45         "}"
  46    }
  47 };
  48
  49 #define VG_LINES_BUFFER_SIZE 50000 * sizeof( struct vg_lines_vert )
  50
  51 static void async_vg_lines_init( void *payload, u32 payload_size )
  52 {
  53    glGenVertexArrays( 1, &vg_lines.vao );
  54    glGenBuffers( 1, &vg_lines.vbo );
  55    glBindVertexArray( vg_lines.vao );
  56    glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  57
  58    glBufferData( GL_ARRAY_BUFFER, VG_LINES_BUFFER_SIZE, NULL, GL_DYNAMIC_DRAW );
  59    glBindVertexArray( vg_lines.vao );
  60    VG_CHECK_GL_ERR();
  61
  62    /* Pointers */
  63    glVertexAttribPointer(
  64       0,
  65       3,
  66       GL_FLOAT,
  67       GL_FALSE,
  68       sizeof( struct vg_lines_vert ),
  69       (void *)0
  70    );
  71    glEnableVertexAttribArray( 0 );
  72
  73    glVertexAttribPointer(
  74       1,
  75       4,
  76       GL_UNSIGNED_BYTE,
  77       GL_TRUE,
  78       sizeof( struct vg_lines_vert ),
  79       (void*)(offsetof( struct vg_lines_vert, colour ))
  80    );
  81    glEnableVertexAttribArray( 1 );
  82
  83    VG_CHECK_GL_ERR();
  84 }
  85
  86 void vg_lines_init(void)
  87 {
  88    vg_lines.vertex_buffer =
  89       vg_create_linear_allocator( vg_mem.rtmemory,
  90                                   VG_LINES_BUFFER_SIZE, VG_MEMORY_REALTIME);
  91
  92    vg_async_call( async_vg_lines_init, NULL, 0 );
  93
  94    vg_console_reg_var( "vg_lines", &vg_lines.render, k_var_dtype_i32,
  95                        VG_VAR_CHEAT );
  96    vg_shader_register( &_shader_lines );
  97 }
  98
  99 void vg_lines_drawall( void )
 100 {
 101         glUseProgram( _shader_lines.id );
 102
 103    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 104      1, GL_FALSE, (float *)vg.pv );
 105
 106         glBindVertexArray( vg_lines.vao );
 107         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 108
 109    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 110         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 111
 112         glEnable( GL_BLEND );
 113         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 114         glBlendEquation( GL_FUNC_ADD );
 115
 116    if( vg_lines.render )
 117       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 118
 119         glDisable( GL_BLEND );
 120    vg_linear_clear( vg_lines.vertex_buffer );
 121 }
 122
 123 void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 124 {
 125    if( !vg_lines.enabled ) return;
 126
 127    u32 size = 2 * sizeof(struct vg_lines_vert);
 128         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 129
 130         v3_copy( from, v[0].co );
 131         v3_copy( to, v[1].co );
 132
 133         v[0].colour = fc;
 134         v[1].colour = tc;
 135 }
 136
 137 void vg_line( line_co from, line_co to, u32 colour )
 138 {
 139    if( !vg_lines.enabled ) return;
 140
 141         vg_line2( from, to, colour, colour );
 142 }
 143
 144 void vg_line_arrow( line_co co, line_co dir, float size, u32 colour )
 145 {
 146    if( !vg_lines.enabled ) return;
 147
 148    v3f p1, tx, ty, p2, p3;
 149    v3_muladds( co, dir, size, p1 );
 150    v3_tangent_basis( dir, tx, ty );
 151
 152    v3_muladds( p1, dir, -size * 0.125f, p2 );
 153    v3_muladds( p2, ty,  size * 0.125f, p3 );
 154    v3_muladds( p2, ty, -size * 0.125f, p2 );
 155
 156    vg_line( co, p1, colour );
 157    vg_line( p1, p2, colour );
 158    vg_line( p1, p3, colour );
 159 }
 160
 161 void vg_line_box_verts( boxf box, v3f verts[8] )
 162 {
 163    if( !vg_lines.enabled ) return;
 164
 165    for( u32 i=0; i<8; i++ ){
 166       for( u32 j=0; j<3; j++ ){
 167          verts[i][j] = i&(0x1<<j)? box[1][j]: box[0][j];
 168       }
 169    }
 170 }
 171
 172 void vg_line_mesh( v3f verts[], u32 indices[][2], u32 indice_count,u32 colour ){
 173    if( !vg_lines.enabled ) return;
 174
 175    for( u32 i=0; i<indice_count; i++ ){
 176       vg_line( verts[indices[i][0]], verts[indices[i][1]], colour );
 177    }
 178 }
 179
 180 void vg_line_boxf( boxf box, u32 colour )
 181 {
 182    if( !vg_lines.enabled ) return;
 183
 184    v3f verts[8];
 185    vg_line_box_verts( box, verts );
 186    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 187                        {4,5},{5,7},{7,6},{6,4},
 188                        {4,0},{5,1},{6,2},{7,3}};
 189
 190    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 191 }
 192
 193 void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour )
 194 {
 195    if( !vg_lines.enabled ) return;
 196
 197    v3f verts[8];
 198    vg_line_box_verts( box, verts );
 199
 200    for( u32 i=0; i<8; i++ ){
 201       m4x3_mulv( m, verts[i], verts[i] );
 202    }
 203
 204    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 205                        {4,5},{5,7},{7,6},{6,4},
 206                        {4,0},{5,1},{6,2},{7,3}};
 207
 208    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 209 }
 210
 211 void vg_line_cross(v3f pos,u32 colour, float scale)
 212 {
 213    if( !vg_lines.enabled ) return;
 214
 215    v3f p0, p1;
 216    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 217    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 218    vg_line( p0, p1, colour );
 219    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 220    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 221    vg_line( p0, p1, colour );
 222    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 223    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 224    vg_line( p0, p1, colour );
 225 }
 226
 227 void vg_line_point( v3f pt, float size, u32 colour )
 228 {
 229    if( !vg_lines.enabled ) return;
 230
 231    boxf box =
 232    {
 233       { pt[0]-size, pt[1]-size, pt[2]-size },
 234       { pt[0]+size, pt[1]+size, pt[2]+size }
 235    };
 236
 237    vg_line_boxf( box, colour );
 238 }
 239
 240
 241 void vg_line_sphere( m4x3f m, float radius, u32 colour )
 242 {
 243    if( !vg_lines.enabled ) return;
 244
 245    v3f ly = { 0.0f, 0.0f, radius },
 246        lx = { 0.0f, radius, 0.0f },
 247        lz = { 0.0f, 0.0f, radius };
 248
 249    for( int i=0; i<16; i++ ){
 250       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 251             s = sinf(t),
 252             c = cosf(t);
 253
 254       v3f py = { s*radius, 0.0f, c*radius },
 255           px = { s*radius, c*radius, 0.0f },
 256           pz = { 0.0f, s*radius, c*radius };
 257
 258       v3f p0, p1, p2, p3, p4, p5;
 259       m4x3_mulv( m, py, p0 );
 260       m4x3_mulv( m, ly, p1 );
 261       m4x3_mulv( m, px, p2 );
 262       m4x3_mulv( m, lx, p3 );
 263       m4x3_mulv( m, pz, p4 );
 264       m4x3_mulv( m, lz, p5 );
 265
 266       vg_line( p0, p1, colour == 0x00? 0xff00ff00: colour );
 267       vg_line( p2, p3, colour == 0x00? 0xff0000ff: colour );
 268       vg_line( p4, p5, colour == 0x00? 0xffff0000: colour );
 269
 270       v3_copy( py, ly );
 271       v3_copy( px, lx );
 272       v3_copy( pz, lz );
 273    }
 274 }
 275
 276 void vg_line_capsule( m4x3f m, float radius, float h, u32 colour )
 277 {
 278    if( !vg_lines.enabled ) return;
 279
 280    v3f ly = { 0.0f, 0.0f, radius },
 281        lx = { 0.0f, radius, 0.0f },
 282        lz = { 0.0f, 0.0f, radius };
 283
 284    float s0 = sinf(0.0f)*radius,
 285          c0 = cosf(0.0f)*radius;
 286
 287    v3f p0, p1, up, right, forward;
 288    m3x3_mulv( m, (v3f){0.0f,1.0f,0.0f}, up );
 289    m3x3_mulv( m, (v3f){1.0f,0.0f,0.0f}, right );
 290    m3x3_mulv( m, (v3f){0.0f,0.0f,-1.0f}, forward );
 291    v3_muladds( m[3], up, -h*0.5f+radius, p0 );
 292    v3_muladds( m[3], up,  h*0.5f-radius, p1 );
 293
 294    v3f a0, a1, b0, b1;
 295    v3_muladds( p0, right, radius, a0 );
 296    v3_muladds( p1, right, radius, a1 );
 297    v3_muladds( p0, forward, radius, b0 );
 298    v3_muladds( p1, forward, radius, b1 );
 299    vg_line( a0, a1, colour );
 300    vg_line( b0, b1, colour );
 301
 302    v3_muladds( p0, right, -radius, a0 );
 303    v3_muladds( p1, right, -radius, a1 );
 304    v3_muladds( p0, forward, -radius, b0 );
 305    v3_muladds( p1, forward, -radius, b1 );
 306    vg_line( a0, a1, colour );
 307    vg_line( b0, b1, colour );
 308
 309    for( int i=0; i<16; i++ ){
 310       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 311             s1 = sinf(t)*radius,
 312             c1 = cosf(t)*radius;
 313
 314       v3f e0 = { s0, 0.0f, c0 },
 315           e1 = { s1, 0.0f, c1 },
 316           e2 = { s0, c0, 0.0f },
 317           e3 = { s1, c1, 0.0f },
 318           e4 = { 0.0f, c0, s0 },
 319           e5 = { 0.0f, c1, s1 };
 320
 321       m3x3_mulv( m, e0, e0 );
 322       m3x3_mulv( m, e1, e1 );
 323       m3x3_mulv( m, e2, e2 );
 324       m3x3_mulv( m, e3, e3 );
 325       m3x3_mulv( m, e4, e4 );
 326       m3x3_mulv( m, e5, e5 );
 327
 328       v3_add( p0, e0, a0 );
 329       v3_add( p0, e1, a1 );
 330       v3_add( p1, e0, b0 );
 331       v3_add( p1, e1, b1 );
 332
 333       vg_line( a0, a1, colour );
 334       vg_line( b0, b1, colour );
 335
 336       if( c0 < 0.0f ){
 337          v3_add( p0, e2, a0 );
 338          v3_add( p0, e3, a1 );
 339          v3_add( p0, e4, b0 );
 340          v3_add( p0, e5, b1 );
 341       }
 342       else{
 343          v3_add( p1, e2, a0 );
 344          v3_add( p1, e3, a1 );
 345          v3_add( p1, e4, b0 );
 346          v3_add( p1, e5, b1 );
 347       }
 348
 349       vg_line( a0, a1, colour );
 350       vg_line( b0, b1, colour );
 351
 352       s0 = s1;
 353       c0 = c1;
 354    }
 355 }