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 draw,
  63        allow_input;
  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 static void async_vg_lines_init( void *payload, u32 payload_size ){
  76    glGenVertexArrays( 1, &vg_lines.vao );
  77    glGenBuffers( 1, &vg_lines.vbo );
  78    glBindVertexArray( vg_lines.vao );
  79    glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  80
  81    u32 size = 50000 * sizeof( struct vg_lines_vert );
  82
  83    vg_lines.vertex_buffer =
  84       vg_create_linear_allocator(vg_mem.rtmemory, size, VG_MEMORY_REALTIME);
  85
  86    glBufferData( GL_ARRAY_BUFFER, size, NULL, GL_DYNAMIC_DRAW );
  87    glBindVertexArray( vg_lines.vao );
  88    VG_CHECK_GL_ERR();
  89
  90    /* Pointers */
  91    glVertexAttribPointer(
  92       0,
  93       3,
  94       GL_FLOAT,
  95       GL_FALSE,
  96       sizeof( struct vg_lines_vert ),
  97       (void *)0
  98    );
  99    glEnableVertexAttribArray( 0 );
 100
 101    glVertexAttribPointer(
 102       1,
 103       4,
 104       GL_UNSIGNED_BYTE,
 105       GL_TRUE,
 106       sizeof( struct vg_lines_vert ),
 107       (void*)(offsetof( struct vg_lines_vert, colour ))
 108    );
 109    glEnableVertexAttribArray( 1 );
 110
 111    VG_CHECK_GL_ERR();
 112    vg_lines.allow_input = 1;
 113 }
 114
 115 static void vg_lines_init(void){
 116    vg_async_call( async_vg_lines_init, NULL, 0 );
 117
 118    vg_console_reg_var( "vg_lines", &vg_lines.draw, k_var_dtype_i32,
 119                        VG_VAR_CHEAT );
 120    vg_shader_register( &_shader_lines );
 121
 122 }
 123
 124 static void vg_lines_drawall( void ){
 125         glUseProgram( _shader_lines.id );
 126
 127    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 128      1, GL_FALSE, (float *)vg.pv );
 129
 130         glBindVertexArray( vg_lines.vao );
 131         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 132
 133    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 134
 135         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 136
 137         glEnable( GL_BLEND );
 138         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 139         glBlendEquation( GL_FUNC_ADD );
 140
 141    if( vg_lines.draw )
 142       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 143
 144         glDisable( GL_BLEND );
 145    vg_linear_clear( vg_lines.vertex_buffer );
 146 }
 147
 148 static void vg_line2( line_co from, line_co to, u32 fc, u32 tc ){
 149    if( !vg_lines.allow_input ) return;
 150    if( !vg_lines.draw ) return;
 151
 152    u32 size = 2 * sizeof(struct vg_lines_vert);
 153         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 154
 155         v3_copy( from, v[0].co );
 156         v3_copy( to, v[1].co );
 157
 158         v[0].colour = fc;
 159         v[1].colour = tc;
 160 }
 161
 162 static void vg_line( line_co from, line_co to, u32 colour ){
 163         vg_line2( from, to, colour, colour );
 164 }
 165
 166 static void vg_line_arrow( line_co co, line_co dir, float size, u32 colour ){
 167    v3f p1, tx, ty, p2, p3;
 168    v3_muladds( co, dir, size, p1 );
 169    v3_tangent_basis( dir, tx, ty );
 170
 171    v3_muladds( p1, dir, -size * 0.125f, p2 );
 172    v3_muladds( p2, ty,  size * 0.125f, p3 );
 173    v3_muladds( p2, ty, -size * 0.125f, p2 );
 174
 175    vg_line( co, p1, colour );
 176    vg_line( p1, p2, colour );
 177    vg_line( p1, p3, colour );
 178 }
 179
 180 static void vg_line_box_verts( boxf box, v3f verts[8] ){
 181    for( u32 i=0; i<8; i++ ){
 182       for( u32 j=0; j<3; j++ ){
 183          verts[i][j] = i&(0x1<<j)? box[1][j]: box[0][j];
 184       }
 185    }
 186 }
 187
 188 static void vg_line_mesh( v3f verts[], u32 indices[][2], u32 indice_count,
 189                              u32 colour ){
 190    for( u32 i=0; i<indice_count; i++ ){
 191       vg_line( verts[indices[i][0]], verts[indices[i][1]], colour );
 192    }
 193 }
 194
 195 static void vg_line_boxf( boxf box, u32 colour ){
 196    v3f verts[8];
 197    vg_line_box_verts( box, verts );
 198    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 199                        {4,5},{5,7},{7,6},{6,4},
 200                        {4,0},{5,1},{6,2},{7,3}};
 201
 202    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 203 }
 204
 205 static void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour ){
 206    v3f verts[8];
 207    vg_line_box_verts( box, verts );
 208
 209    for( u32 i=0; i<8; i++ ){
 210       m4x3_mulv( m, verts[i], verts[i] );
 211    }
 212
 213    u32 indices[][2] = {{0,1},{1,3},{3,2},{2,0},
 214                        {4,5},{5,7},{7,6},{6,4},
 215                        {4,0},{5,1},{6,2},{7,3}};
 216
 217    vg_line_mesh( verts, indices, vg_list_size(indices), colour );
 218 }
 219
 220 static void vg_line_cross(v3f pos,u32 colour, float scale){
 221    v3f p0, p1;
 222    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 223    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 224    vg_line( p0, p1, colour );
 225    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 226    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 227    vg_line( p0, p1, colour );
 228    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 229    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 230    vg_line( p0, p1, colour );
 231 }
 232
 233 static void vg_line_point( v3f pt, float size, u32 colour ){
 234    boxf box =
 235    {
 236       { pt[0]-size, pt[1]-size, pt[2]-size },
 237       { pt[0]+size, pt[1]+size, pt[2]+size }
 238    };
 239
 240    vg_line_boxf( box, colour );
 241 }
 242
 243
 244 static void vg_line_sphere( m4x3f m, float radius, u32 colour ){
 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 static void vg_line_capsule( m4x3f m, float radius, float h, u32 colour ){
 277    v3f ly = { 0.0f, 0.0f, radius },
 278        lx = { 0.0f, radius, 0.0f },
 279        lz = { 0.0f, 0.0f, radius };
 280
 281    float s0 = sinf(0.0f)*radius,
 282          c0 = cosf(0.0f)*radius;
 283
 284    v3f p0, p1, up, right, forward;
 285    m3x3_mulv( m, (v3f){0.0f,1.0f,0.0f}, up );
 286    m3x3_mulv( m, (v3f){1.0f,0.0f,0.0f}, right );
 287    m3x3_mulv( m, (v3f){0.0f,0.0f,-1.0f}, forward );
 288    v3_muladds( m[3], up, -h*0.5f+radius, p0 );
 289    v3_muladds( m[3], up,  h*0.5f-radius, p1 );
 290
 291    v3f a0, a1, b0, b1;
 292    v3_muladds( p0, right, radius, a0 );
 293    v3_muladds( p1, right, radius, a1 );
 294    v3_muladds( p0, forward, radius, b0 );
 295    v3_muladds( p1, forward, radius, b1 );
 296    vg_line( a0, a1, colour );
 297    vg_line( b0, b1, colour );
 298
 299    v3_muladds( p0, right, -radius, a0 );
 300    v3_muladds( p1, right, -radius, a1 );
 301    v3_muladds( p0, forward, -radius, b0 );
 302    v3_muladds( p1, forward, -radius, b1 );
 303    vg_line( a0, a1, colour );
 304    vg_line( b0, b1, colour );
 305
 306    for( int i=0; i<16; i++ ){
 307       float t = ((float)(i+1) * (1.0f/16.0f)) * VG_PIf * 2.0f,
 308             s1 = sinf(t)*radius,
 309             c1 = cosf(t)*radius;
 310
 311       v3f e0 = { s0, 0.0f, c0 },
 312           e1 = { s1, 0.0f, c1 },
 313           e2 = { s0, c0, 0.0f },
 314           e3 = { s1, c1, 0.0f },
 315           e4 = { 0.0f, c0, s0 },
 316           e5 = { 0.0f, c1, s1 };
 317
 318       m3x3_mulv( m, e0, e0 );
 319       m3x3_mulv( m, e1, e1 );
 320       m3x3_mulv( m, e2, e2 );
 321       m3x3_mulv( m, e3, e3 );
 322       m3x3_mulv( m, e4, e4 );
 323       m3x3_mulv( m, e5, e5 );
 324
 325       v3_add( p0, e0, a0 );
 326       v3_add( p0, e1, a1 );
 327       v3_add( p1, e0, b0 );
 328       v3_add( p1, e1, b1 );
 329
 330       vg_line( a0, a1, colour );
 331       vg_line( b0, b1, colour );
 332
 333       if( c0 < 0.0f ){
 334          v3_add( p0, e2, a0 );
 335          v3_add( p0, e3, a1 );
 336          v3_add( p0, e4, b0 );
 337          v3_add( p0, e5, b1 );
 338       }
 339       else{
 340          v3_add( p1, e2, a0 );
 341          v3_add( p1, e3, a1 );
 342          v3_add( p1, e4, b0 );
 343          v3_add( p1, e5, b1 );
 344       }
 345
 346       vg_line( a0, a1, colour );
 347       vg_line( b0, b1, colour );
 348
 349       s0 = s1;
 350       c0 = c1;
 351    }
 352 }
 353
 354 #endif /* VG_LINES_H */