vg_lines.h

   1 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
   2
   3 #ifndef VG_LINES_H
   4 #define VG_LINES_H
   5
   6 #define VG_GAME
   7 #include "vg/vg.h"
   8
   9 /*
  10  * FIXME: The line buffer sometimes overflows. Low priority
  11  */
  12
  13 typedef v3f line_co;
  14
  15 #define VG__RED   0xff0000ff
  16 #define VG__GREEN 0xff00ff00
  17 #define VG__BLUE  0xffff0000
  18 #define VG__WHITE 0xffffffff
  19 #define VG__BLACK 0xff000000
  20 #define VG__CLEAR 0x00ffffff
  21 #define VG__PINK  0xffff00ff
  22 #define VG__YELOW 0xff00ffff
  23 #define VG__CYAN  0xffffff00
  24 #define VG__NONE  0x00000000
  25
  26 static struct vg_shader _shader_lines = {
  27    .name = "[vg] lines",
  28    .link = NULL,
  29    .vs = {
  30       .orig_file = NULL,
  31       .static_src =
  32
  33         "uniform mat4 uPv;"
  34         "layout (location=0) in vec3 a_co;"
  35         "layout (location=1) in vec4 a_colour;"
  36         ""
  37         "out vec4 s_colour;"
  38         ""
  39         "void main()"
  40         "{"
  41         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  42         "  s_colour = a_colour;"
  43         "       gl_Position = vert_pos;"
  44         "}"
  45    },
  46    .fs = {
  47       .orig_file = NULL,
  48       .static_src =
  49
  50         "out vec4 FragColor;"
  51         ""
  52         "in vec4 s_colour;"
  53         ""
  54         "void main()"
  55         "{"
  56         "       FragColor = s_colour;"
  57         "}"
  58    }
  59 };
  60
  61 struct{
  62    u32 enabled,
  63        render;
  64
  65    struct vg_lines_vert{
  66       v3f co;
  67       u32 colour;
  68    }
  69    *vertex_buffer;
  70
  71         GLuint vao, vbo;
  72 }
  73 static vg_lines;
  74
  75 #define VG_LINES_BUFFER_SIZE 50000 * sizeof( struct vg_lines_vert )
  76
  77 static void async_vg_lines_init( void *payload, u32 payload_size ){
  78    glGenVertexArrays( 1, &vg_lines.vao );
  79    glGenBuffers( 1, &vg_lines.vbo );
  80    glBindVertexArray( vg_lines.vao );
  81    glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  82
  83    glBufferData( GL_ARRAY_BUFFER, VG_LINES_BUFFER_SIZE, NULL, GL_DYNAMIC_DRAW );
  84    glBindVertexArray( vg_lines.vao );
  85    VG_CHECK_GL_ERR();
  86
  87    /* Pointers */
  88    glVertexAttribPointer(
  89       0,
  90       3,
  91       GL_FLOAT,
  92       GL_FALSE,
  93       sizeof( struct vg_lines_vert ),
  94       (void *)0
  95    );
  96    glEnableVertexAttribArray( 0 );
  97
  98    glVertexAttribPointer(
  99       1,
 100       4,
 101       GL_UNSIGNED_BYTE,
 102       GL_TRUE,
 103       sizeof( struct vg_lines_vert ),
 104       (void*)(offsetof( struct vg_lines_vert, colour ))
 105    );
 106    glEnableVertexAttribArray( 1 );
 107
 108    VG_CHECK_GL_ERR();
 109 }
 110
 111 static void vg_lines_init(void){
 112    vg_lines.vertex_buffer =
 113       vg_create_linear_allocator( vg_mem.rtmemory,
 114                                   VG_LINES_BUFFER_SIZE, VG_MEMORY_REALTIME);
 115
 116    vg_async_call( async_vg_lines_init, NULL, 0 );
 117
 118    vg_console_reg_var( "vg_lines", &vg_lines.render, k_var_dtype_i32,
 119                        VG_VAR_CHEAT );
 120    vg_shader_register( &_shader_lines );
 121 }
 122
 123 static void vg_lines_drawall( void ){
 124         glUseProgram( _shader_lines.id );
 125
 126    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 127      1, GL_FALSE, (float *)vg.pv );
 128
 129         glBindVertexArray( vg_lines.vao );
 130         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 131
 132    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 133         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 134
 135         glEnable( GL_BLEND );
 136         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 137         glBlendEquation( GL_FUNC_ADD );
 138
 139    if( vg_lines.render )
 140       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 141
 142         glDisable( GL_BLEND );
 143    vg_linear_clear( vg_lines.vertex_buffer );
 144 }
 145
 146 static void vg_line2( line_co from, line_co to, u32 fc, u32 tc ){
 147    if( !vg_lines.enabled ) return;
 148
 149    u32 size = 2 * sizeof(struct vg_lines_vert);
 150         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 151
 152         v3_copy( from, v[0].co );
 153         v3_copy( to, v[1].co );
 154
 155         v[0].colour = fc;
 156         v[1].colour = tc;
 157 }
 158
 159 static void vg_line( line_co from, line_co to, u32 colour ){
 160    if( !vg_lines.enabled ) return;
 161
 162         vg_line2( from, to, colour, colour );
 163 }
 164
 165 static void vg_line_arrow( line_co co, line_co dir, float size, u32 colour ){
 166    if( !vg_lines.enabled ) return;
 167
 168    v3f p1, tx, ty, p2, p3;
 169    v3_muladds( co, dir, size, p1 );
 170    v3_tangent_basis( dir, tx, ty );
 171
 172    v3_muladds( p1, dir, -size * 0.125f, p2 );
 173    v3_muladds( p2, ty,  size * 0.125f, p3 );
 174    v3_muladds( p2, ty, -size * 0.125f, p2 );
 175
 176    vg_line( co, p1, colour );
 177    vg_line( p1, p2, colour );
 178    vg_line( p1, p3, colour );
 179 }
 180
 181 static void vg_line_box_verts( boxf box, v3f verts[8] ){
 182    if( !vg_lines.enabled ) return;
 183
 184    for( u32 i=0; i<8; i++ ){
 185       for( u32 j=0; j<3; j++ ){
 186          verts[i][j] = i&(0x1<<j)? box[1][j]: box[0][j];
 187       }
 188    }
 189 }
 190
 191 static void vg_line_mesh( v3f verts[], u32 indices[][2], u32 indice_count,
 192                              u32 colour ){
 193    if( !vg_lines.enabled ) return;
 194
 195    for( u32 i=0; i<indice_count; i++ ){
 196       vg_line( verts[indices[i][0]], verts[indices[i][1]], colour );
 197    }
 198 }
 199
 200 static void vg_line_boxf( boxf box, u32 colour ){
 201    if( !vg_lines.enabled ) return;
 202
 203    v3f verts[8];
 204    vg_line_box_verts( box, verts );
 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 static void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour ){
 213    if( !vg_lines.enabled ) return;
 214
 215    v3f verts[8];
 216    vg_line_box_verts( box, verts );
 217
 218    for( u32 i=0; i<8; i++ ){
 219       m4x3_mulv( m, verts[i], verts[i] );
 220    }
 221
 222    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 223                        {4,5},{5,7},{7,6},{6,4},
 224                        {4,0},{5,1},{6,2},{7,3}};
 225
 226    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 227 }
 228
 229 static void vg_line_cross(v3f pos,u32 colour, float scale){
 230    if( !vg_lines.enabled ) return;
 231
 232    v3f p0, p1;
 233    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 234    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 235    vg_line( p0, p1, colour );
 236    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 237    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 238    vg_line( p0, p1, colour );
 239    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 240    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 241    vg_line( p0, p1, colour );
 242 }
 243
 244 static void vg_line_point( v3f pt, float size, u32 colour ){
 245    if( !vg_lines.enabled ) return;
 246
 247    boxf box =
 248    {
 249       { pt[0]-size, pt[1]-size, pt[2]-size },
 250       { pt[0]+size, pt[1]+size, pt[2]+size }
 251    };
 252
 253    vg_line_boxf( box, colour );
 254 }
 255
 256
 257 static void vg_line_sphere( m4x3f m, float radius, u32 colour ){
 258    if( !vg_lines.enabled ) return;
 259
 260    v3f ly = { 0.0f, 0.0f, radius },
 261        lx = { 0.0f, radius, 0.0f },
 262        lz = { 0.0f, 0.0f, radius };
 263
 264    for( int i=0; i<16; i++ ){
 265       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 266             s = sinf(t),
 267             c = cosf(t);
 268
 269       v3f py = { s*radius, 0.0f, c*radius },
 270           px = { s*radius, c*radius, 0.0f },
 271           pz = { 0.0f, s*radius, c*radius };
 272
 273       v3f p0, p1, p2, p3, p4, p5;
 274       m4x3_mulv( m, py, p0 );
 275       m4x3_mulv( m, ly, p1 );
 276       m4x3_mulv( m, px, p2 );
 277       m4x3_mulv( m, lx, p3 );
 278       m4x3_mulv( m, pz, p4 );
 279       m4x3_mulv( m, lz, p5 );
 280
 281       vg_line( p0, p1, colour == 0x00? 0xff00ff00: colour );
 282       vg_line( p2, p3, colour == 0x00? 0xff0000ff: colour );
 283       vg_line( p4, p5, colour == 0x00? 0xffff0000: colour );
 284
 285       v3_copy( py, ly );
 286       v3_copy( px, lx );
 287       v3_copy( pz, lz );
 288    }
 289 }
 290
 291 static void vg_line_capsule( m4x3f m, float radius, float h, u32 colour ){
 292    if( !vg_lines.enabled ) return;
 293
 294    v3f ly = { 0.0f, 0.0f, radius },
 295        lx = { 0.0f, radius, 0.0f },
 296        lz = { 0.0f, 0.0f, radius };
 297
 298    float s0 = sinf(0.0f)*radius,
 299          c0 = cosf(0.0f)*radius;
 300
 301    v3f p0, p1, up, right, forward;
 302    m3x3_mulv( m, (v3f){0.0f,1.0f,0.0f}, up );
 303    m3x3_mulv( m, (v3f){1.0f,0.0f,0.0f}, right );
 304    m3x3_mulv( m, (v3f){0.0f,0.0f,-1.0f}, forward );
 305    v3_muladds( m[3], up, -h*0.5f+radius, p0 );
 306    v3_muladds( m[3], up,  h*0.5f-radius, p1 );
 307
 308    v3f a0, a1, b0, b1;
 309    v3_muladds( p0, right, radius, a0 );
 310    v3_muladds( p1, right, radius, a1 );
 311    v3_muladds( p0, forward, radius, b0 );
 312    v3_muladds( p1, forward, radius, b1 );
 313    vg_line( a0, a1, colour );
 314    vg_line( b0, b1, colour );
 315
 316    v3_muladds( p0, right, -radius, a0 );
 317    v3_muladds( p1, right, -radius, a1 );
 318    v3_muladds( p0, forward, -radius, b0 );
 319    v3_muladds( p1, forward, -radius, b1 );
 320    vg_line( a0, a1, colour );
 321    vg_line( b0, b1, colour );
 322
 323    for( int i=0; i<16; i++ ){
 324       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 325             s1 = sinf(t)*radius,
 326             c1 = cosf(t)*radius;
 327
 328       v3f e0 = { s0, 0.0f, c0 },
 329           e1 = { s1, 0.0f, c1 },
 330           e2 = { s0, c0, 0.0f },
 331           e3 = { s1, c1, 0.0f },
 332           e4 = { 0.0f, c0, s0 },
 333           e5 = { 0.0f, c1, s1 };
 334
 335       m3x3_mulv( m, e0, e0 );
 336       m3x3_mulv( m, e1, e1 );
 337       m3x3_mulv( m, e2, e2 );
 338       m3x3_mulv( m, e3, e3 );
 339       m3x3_mulv( m, e4, e4 );
 340       m3x3_mulv( m, e5, e5 );
 341
 342       v3_add( p0, e0, a0 );
 343       v3_add( p0, e1, a1 );
 344       v3_add( p1, e0, b0 );
 345       v3_add( p1, e1, b1 );
 346
 347       vg_line( a0, a1, colour );
 348       vg_line( b0, b1, colour );
 349
 350       if( c0 < 0.0f ){
 351          v3_add( p0, e2, a0 );
 352          v3_add( p0, e3, a1 );
 353          v3_add( p0, e4, b0 );
 354          v3_add( p0, e5, b1 );
 355       }
 356       else{
 357          v3_add( p1, e2, a0 );
 358          v3_add( p1, e3, a1 );
 359          v3_add( p1, e4, b0 );
 360          v3_add( p1, e5, b1 );
 361       }
 362
 363       vg_line( a0, a1, colour );
 364       vg_line( b0, b1, colour );
 365
 366       s0 = s1;
 367       c0 = c1;
 368    }
 369 }
 370
 371 #endif /* VG_LINES_H */