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    .link = NULL,
  18    .vs = {
  19       .orig_file = NULL,
  20       .static_src =
  21
  22         "uniform mat4 uPv;"
  23         "layout (location=0) in vec3 a_co;"
  24         "layout (location=1) in vec4 a_colour;"
  25         ""
  26         "out vec4 s_colour;"
  27         ""
  28         "void main()"
  29         "{"
  30         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  31         "  s_colour = a_colour;"
  32         "       gl_Position = vert_pos;"
  33         "}"
  34    },
  35    .fs = {
  36       .orig_file = NULL,
  37       .static_src =
  38
  39         "out vec4 FragColor;"
  40         ""
  41         "in vec4 s_colour;"
  42         ""
  43         "void main()"
  44         "{"
  45         "       FragColor = s_colour;"
  46         "}"
  47    }
  48 };
  49
  50 #define VG_LINES_BUFFER_SIZE 50000 * sizeof( struct vg_lines_vert )
  51
  52 static void async_vg_lines_init( void *payload, u32 payload_size )
  53 {
  54    glGenVertexArrays( 1, &vg_lines.vao );
  55    glGenBuffers( 1, &vg_lines.vbo );
  56    glBindVertexArray( vg_lines.vao );
  57    glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  58
  59    glBufferData( GL_ARRAY_BUFFER, VG_LINES_BUFFER_SIZE, NULL, GL_DYNAMIC_DRAW );
  60    glBindVertexArray( vg_lines.vao );
  61    VG_CHECK_GL_ERR();
  62
  63    /* Pointers */
  64    glVertexAttribPointer(
  65       0,
  66       3,
  67       GL_FLOAT,
  68       GL_FALSE,
  69       sizeof( struct vg_lines_vert ),
  70       (void *)0
  71    );
  72    glEnableVertexAttribArray( 0 );
  73
  74    glVertexAttribPointer(
  75       1,
  76       4,
  77       GL_UNSIGNED_BYTE,
  78       GL_TRUE,
  79       sizeof( struct vg_lines_vert ),
  80       (void*)(offsetof( struct vg_lines_vert, colour ))
  81    );
  82    glEnableVertexAttribArray( 1 );
  83
  84    VG_CHECK_GL_ERR();
  85 }
  86
  87 void vg_lines_init(void)
  88 {
  89    vg_lines.vertex_buffer =
  90       vg_create_linear_allocator( vg_mem.rtmemory,
  91                                   VG_LINES_BUFFER_SIZE, VG_MEMORY_REALTIME);
  92
  93    vg_async_call( async_vg_lines_init, NULL, 0 );
  94
  95    vg_console_reg_var( "vg_lines", &vg_lines.render, k_var_dtype_i32,
  96                        VG_VAR_CHEAT );
  97    vg_shader_register( &_shader_lines );
  98 }
  99
 100 void vg_lines_drawall( void )
 101 {
 102         glUseProgram( _shader_lines.id );
 103
 104    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 105      1, GL_FALSE, (float *)vg.pv );
 106
 107         glBindVertexArray( vg_lines.vao );
 108         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 109
 110    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 111         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 112
 113         glEnable( GL_BLEND );
 114         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 115         glBlendEquation( GL_FUNC_ADD );
 116
 117    if( vg_lines.render )
 118       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 119
 120         glDisable( GL_BLEND );
 121    vg_linear_clear( vg_lines.vertex_buffer );
 122 }
 123
 124 void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 125 {
 126    if( !vg_lines.enabled ) return;
 127
 128    u32 size = 2 * sizeof(struct vg_lines_vert);
 129         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 130
 131         v3_copy( from, v[0].co );
 132         v3_copy( to, v[1].co );
 133
 134         v[0].colour = fc;
 135         v[1].colour = tc;
 136 }
 137
 138 void vg_line( line_co from, line_co to, u32 colour )
 139 {
 140    if( !vg_lines.enabled ) return;
 141
 142         vg_line2( from, to, colour, colour );
 143 }
 144
 145 void vg_line_arrow( line_co co, line_co dir, float size, u32 colour )
 146 {
 147    if( !vg_lines.enabled ) return;
 148
 149    v3f p1, tx, ty, p2, p3;
 150    v3_muladds( co, dir, size, p1 );
 151    v3_tangent_basis( dir, tx, ty );
 152
 153    v3_muladds( p1, dir, -size * 0.125f, p2 );
 154    v3_muladds( p2, ty,  size * 0.125f, p3 );
 155    v3_muladds( p2, ty, -size * 0.125f, p2 );
 156
 157    vg_line( co, p1, colour );
 158    vg_line( p1, p2, colour );
 159    vg_line( p1, p3, colour );
 160 }
 161
 162 void vg_line_box_verts( boxf box, v3f verts[8] )
 163 {
 164    if( !vg_lines.enabled ) return;
 165
 166    for( u32 i=0; i<8; i++ ){
 167       for( u32 j=0; j<3; j++ ){
 168          verts[i][j] = i&(0x1<<j)? box[1][j]: box[0][j];
 169       }
 170    }
 171 }
 172
 173 void vg_line_mesh( v3f verts[], u32 indices[][2], u32 indice_count,u32 colour ){
 174    if( !vg_lines.enabled ) return;
 175
 176    for( u32 i=0; i<indice_count; i++ ){
 177       vg_line( verts[indices[i][0]], verts[indices[i][1]], colour );
 178    }
 179 }
 180
 181 void vg_line_boxf( boxf box, u32 colour )
 182 {
 183    if( !vg_lines.enabled ) return;
 184
 185    v3f verts[8];
 186    vg_line_box_verts( box, verts );
 187    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 188                        {4,5},{5,7},{7,6},{6,4},
 189                        {4,0},{5,1},{6,2},{7,3}};
 190
 191    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 192 }
 193
 194 void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour )
 195 {
 196    if( !vg_lines.enabled ) return;
 197
 198    v3f verts[8];
 199    vg_line_box_verts( box, verts );
 200
 201    for( u32 i=0; i<8; i++ ){
 202       m4x3_mulv( m, verts[i], verts[i] );
 203    }
 204
 205    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 206                        {4,5},{5,7},{7,6},{6,4},
 207                        {4,0},{5,1},{6,2},{7,3}};
 208
 209    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 210 }
 211
 212 void vg_line_cross(v3f pos,u32 colour, float scale)
 213 {
 214    if( !vg_lines.enabled ) return;
 215
 216    v3f p0, p1;
 217    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 218    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 219    vg_line( p0, p1, colour );
 220    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 221    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 222    vg_line( p0, p1, colour );
 223    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 224    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 225    vg_line( p0, p1, colour );
 226 }
 227
 228 void vg_line_point( v3f pt, float size, u32 colour )
 229 {
 230    if( !vg_lines.enabled ) return;
 231
 232    boxf box =
 233    {
 234       { pt[0]-size, pt[1]-size, pt[2]-size },
 235       { pt[0]+size, pt[1]+size, pt[2]+size }
 236    };
 237
 238    vg_line_boxf( box, colour );
 239 }
 240
 241
 242 void vg_line_sphere( m4x3f m, float radius, u32 colour )
 243 {
 244    if( !vg_lines.enabled ) return;
 245
 246    v3f ly = { 0.0f, 0.0f, radius },
 247        lx = { 0.0f, radius, 0.0f },
 248        lz = { 0.0f, 0.0f, radius };
 249
 250    for( int i=0; i<16; i++ ){
 251       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 252             s = sinf(t),
 253             c = cosf(t);
 254
 255       v3f py = { s*radius, 0.0f, c*radius },
 256           px = { s*radius, c*radius, 0.0f },
 257           pz = { 0.0f, s*radius, c*radius };
 258
 259       v3f p0, p1, p2, p3, p4, p5;
 260       m4x3_mulv( m, py, p0 );
 261       m4x3_mulv( m, ly, p1 );
 262       m4x3_mulv( m, px, p2 );
 263       m4x3_mulv( m, lx, p3 );
 264       m4x3_mulv( m, pz, p4 );
 265       m4x3_mulv( m, lz, p5 );
 266
 267       vg_line( p0, p1, colour == 0x00? 0xff00ff00: colour );
 268       vg_line( p2, p3, colour == 0x00? 0xff0000ff: colour );
 269       vg_line( p4, p5, colour == 0x00? 0xffff0000: colour );
 270
 271       v3_copy( py, ly );
 272       v3_copy( px, lx );
 273       v3_copy( pz, lz );
 274    }
 275 }
 276
 277 void vg_line_capsule( m4x3f m, float radius, float h, u32 colour )
 278 {
 279    if( !vg_lines.enabled ) return;
 280
 281    v3f ly = { 0.0f, 0.0f, radius },
 282        lx = { 0.0f, radius, 0.0f },
 283        lz = { 0.0f, 0.0f, radius };
 284
 285    float s0 = sinf(0.0f)*radius,
 286          c0 = cosf(0.0f)*radius;
 287
 288    v3f p0, p1, up, right, forward;
 289    m3x3_mulv( m, (v3f){0.0f,1.0f,0.0f}, up );
 290    m3x3_mulv( m, (v3f){1.0f,0.0f,0.0f}, right );
 291    m3x3_mulv( m, (v3f){0.0f,0.0f,-1.0f}, forward );
 292    v3_muladds( m[3], up, -h*0.5f+radius, p0 );
 293    v3_muladds( m[3], up,  h*0.5f-radius, p1 );
 294
 295    v3f a0, a1, b0, b1;
 296    v3_muladds( p0, right, radius, a0 );
 297    v3_muladds( p1, right, radius, a1 );
 298    v3_muladds( p0, forward, radius, b0 );
 299    v3_muladds( p1, forward, radius, b1 );
 300    vg_line( a0, a1, colour );
 301    vg_line( b0, b1, colour );
 302
 303    v3_muladds( p0, right, -radius, a0 );
 304    v3_muladds( p1, right, -radius, a1 );
 305    v3_muladds( p0, forward, -radius, b0 );
 306    v3_muladds( p1, forward, -radius, b1 );
 307    vg_line( a0, a1, colour );
 308    vg_line( b0, b1, colour );
 309
 310    for( int i=0; i<16; i++ ){
 311       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 312             s1 = sinf(t)*radius,
 313             c1 = cosf(t)*radius;
 314
 315       v3f e0 = { s0, 0.0f, c0 },
 316           e1 = { s1, 0.0f, c1 },
 317           e2 = { s0, c0, 0.0f },
 318           e3 = { s1, c1, 0.0f },
 319           e4 = { 0.0f, c0, s0 },
 320           e5 = { 0.0f, c1, s1 };
 321
 322       m3x3_mulv( m, e0, e0 );
 323       m3x3_mulv( m, e1, e1 );
 324       m3x3_mulv( m, e2, e2 );
 325       m3x3_mulv( m, e3, e3 );
 326       m3x3_mulv( m, e4, e4 );
 327       m3x3_mulv( m, e5, e5 );
 328
 329       v3_add( p0, e0, a0 );
 330       v3_add( p0, e1, a1 );
 331       v3_add( p1, e0, b0 );
 332       v3_add( p1, e1, b1 );
 333
 334       vg_line( a0, a1, colour );
 335       vg_line( b0, b1, colour );
 336
 337       if( c0 < 0.0f ){
 338          v3_add( p0, e2, a0 );
 339          v3_add( p0, e3, a1 );
 340          v3_add( p0, e4, b0 );
 341          v3_add( p0, e5, b1 );
 342       }
 343       else{
 344          v3_add( p1, e2, a0 );
 345          v3_add( p1, e3, a1 );
 346          v3_add( p1, e4, b0 );
 347          v3_add( p1, e5, b1 );
 348       }
 349
 350       vg_line( a0, a1, colour );
 351       vg_line( b0, b1, colour );
 352
 353       s0 = s1;
 354       c0 = c1;
 355    }
 356 }