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 typedef v3f line_co;
  10
  11 #define VG__RED   0xff0000ff
  12 #define VG__GREEN 0xff00ff00
  13 #define VG__BLUE  0xffff0000
  14 #define VG__WHITE 0xffffffff
  15 #define VG__BLACK 0xff000000
  16 #define VG__CLEAR 0x00ffffff
  17 #define VG__PINK  0xffff00ff
  18 #define VG__YELOW 0xff00ffff
  19 #define VG__CYAN  0xffffff00
  20 #define VG__NONE  0x00000000
  21
  22 static struct vg_shader _shader_lines = {
  23    .name = "[vg] lines",
  24    .link = NULL,
  25    .vs = {
  26       .orig_file = NULL,
  27       .static_src =
  28
  29         "uniform mat4 uPv;"
  30         "layout (location=0) in vec3 a_co;"
  31         "layout (location=1) in vec4 a_colour;"
  32         ""
  33         "out vec4 s_colour;"
  34         ""
  35         "void main()"
  36         "{"
  37         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  38         "  s_colour = a_colour;"
  39         "       gl_Position = vert_pos;"
  40         "}"
  41    },
  42    .fs = {
  43       .orig_file = NULL,
  44       .static_src =
  45
  46         "out vec4 FragColor;"
  47         ""
  48         "in vec4 s_colour;"
  49         ""
  50         "void main()"
  51         "{"
  52         "       FragColor = s_colour;"
  53         "}"
  54    }
  55 };
  56
  57 struct{
  58    u32 draw,
  59        allow_input;
  60
  61    struct vg_lines_vert{
  62       v3f co;
  63       u32 colour;
  64    }
  65    *vertex_buffer;
  66
  67         GLuint vao, vbo;
  68 }
  69 static vg_lines;
  70
  71 VG_STATIC void async_vg_lines_init( void *payload, u32 payload_size )
  72 {
  73    glGenVertexArrays( 1, &vg_lines.vao );
  74    glGenBuffers( 1, &vg_lines.vbo );
  75    glBindVertexArray( vg_lines.vao );
  76    glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  77
  78    u32 size = 50000 * sizeof( struct vg_lines_vert );
  79
  80    vg_lines.vertex_buffer =
  81       vg_create_linear_allocator(vg_mem.rtmemory, size, VG_MEMORY_REALTIME);
  82
  83    glBufferData( GL_ARRAY_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    vg_success( "done\n" );
 110
 111    vg_lines.allow_input = 1;
 112 }
 113
 114 VG_STATIC void vg_lines_init(void)
 115 {
 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 VG_STATIC void vg_lines_drawall( void )
 125 {
 126         glUseProgram( _shader_lines.id );
 127
 128    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 129      1, GL_FALSE, (float *)vg.pv );
 130
 131         glBindVertexArray( vg_lines.vao );
 132         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 133
 134    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 135
 136         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 137
 138         glEnable( GL_BLEND );
 139         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 140         glBlendEquation( GL_FUNC_ADD );
 141
 142    if( vg_lines.draw )
 143       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 144
 145         glDisable( GL_BLEND );
 146    vg_linear_clear( vg_lines.vertex_buffer );
 147 }
 148
 149 VG_STATIC void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 150 {
 151    if( !vg_lines.allow_input )
 152       return;
 153
 154    u32 size = 2 * sizeof(struct vg_lines_vert);
 155         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 156
 157         v3_copy( from, v[0].co );
 158         v3_copy( to, v[1].co );
 159
 160         v[0].colour = fc;
 161         v[1].colour = tc;
 162 }
 163
 164 VG_STATIC void vg_line( line_co from, line_co to, u32 colour )
 165 {
 166         vg_line2( from, to, colour, colour );
 167 }
 168
 169 VG_STATIC void line_tangent_basis( v3f n, v3f tx, v3f ty )
 170 {
 171    /* Compute tangent basis (box2d) */
 172    if( fabsf( n[0] ) >= 0.57735027f ){
 173       tx[0] =  n[1];
 174       tx[1] = -n[0];
 175       tx[2] =  0.0f;
 176    }
 177    else{
 178       tx[0] =  0.0f;
 179       tx[1] =  n[2];
 180       tx[2] = -n[1];
 181    }
 182
 183    v3_normalize( tx );
 184    v3_cross( n, tx, ty );
 185 }
 186
 187 VG_STATIC void vg_line_arrow( line_co co, line_co dir, float size, u32 colour )
 188 {
 189    v3f p1, tx, ty, p2, p3;
 190    v3_muladds( co, dir, size, p1 );
 191    line_tangent_basis( dir, tx, ty );
 192
 193    v3_muladds( p1, dir, -size * 0.125f, p2 );
 194    v3_muladds( p2, ty,  size * 0.125f, p3 );
 195    v3_muladds( p2, ty, -size * 0.125f, p2 );
 196
 197    vg_line( co, p1, colour );
 198    vg_line( p1, p2, colour );
 199    vg_line( p1, p3, colour );
 200 }
 201
 202 VG_STATIC void vg_line_boxf( boxf box, u32 colour )
 203 {
 204    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 205
 206    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 207    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 208    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 209    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 210
 211    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 212    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 213    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 214    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 215
 216    vg_line( p000, p001, colour );
 217    vg_line( p001, p011, colour );
 218    vg_line( p011, p010, colour );
 219    vg_line( p010, p000, colour );
 220
 221    vg_line( p100, p101, colour );
 222    vg_line( p101, p111, colour );
 223    vg_line( p111, p110, colour );
 224    vg_line( p110, p100, colour );
 225
 226    vg_line( p100, p000, colour );
 227    vg_line( p101, p001, colour );
 228    vg_line( p110, p010, colour );
 229    vg_line( p111, p011, colour );
 230 }
 231
 232 VG_STATIC void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour )
 233 {
 234    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 235
 236    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 237    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 238    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 239    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 240
 241    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 242    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 243    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 244    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 245
 246    m4x3_mulv( m, p000, p000 );
 247    m4x3_mulv( m, p001, p001 );
 248    m4x3_mulv( m, p010, p010 );
 249    m4x3_mulv( m, p011, p011 );
 250    m4x3_mulv( m, p100, p100 );
 251    m4x3_mulv( m, p101, p101 );
 252    m4x3_mulv( m, p110, p110 );
 253    m4x3_mulv( m, p111, p111 );
 254
 255    vg_line( p000, p001, colour );
 256    vg_line( p001, p011, colour );
 257    vg_line( p011, p010, colour );
 258    vg_line( p010, p000, colour );
 259
 260    vg_line( p100, p101, colour );
 261    vg_line( p101, p111, colour );
 262    vg_line( p111, p110, colour );
 263    vg_line( p110, p100, colour );
 264
 265    vg_line( p100, p000, colour );
 266    vg_line( p101, p001, colour );
 267    vg_line( p110, p010, colour );
 268    vg_line( p111, p011, colour );
 269
 270    vg_line( p000, p110, colour );
 271    vg_line( p100, p010, colour );
 272 }
 273
 274 VG_STATIC void vg_line_cross(v3f pos,u32 colour, float scale)
 275 {
 276    v3f p0, p1;
 277    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 278    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 279    vg_line( p0, p1, colour );
 280    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 281    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 282    vg_line( p0, p1, colour );
 283    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 284    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 285    vg_line( p0, p1, colour );
 286 }
 287
 288 VG_STATIC void vg_line_pt3( v3f pt, float size, u32 colour )
 289 {
 290    boxf box =
 291    {
 292       { pt[0]-size, pt[1]-size, pt[2]-size },
 293       { pt[0]+size, pt[1]+size, pt[2]+size }
 294    };
 295
 296    vg_line_boxf( box, colour );
 297 }
 298
 299 #endif /* VG_LINES_H */