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 {
  24    .name = "[vg] lines",
  25    .link = NULL,
  26    .vs =
  27    {
  28       .orig_file = NULL,
  29       .static_src =
  30
  31         "uniform mat4 uPv;"
  32         "layout (location=0) in vec3 a_co;"
  33         "layout (location=1) in vec4 a_colour;"
  34         ""
  35         "out vec4 s_colour;"
  36         ""
  37         "void main()"
  38         "{"
  39         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  40         "  s_colour = a_colour;"
  41         "       gl_Position = vert_pos;"
  42         "}"
  43    },
  44    .fs =
  45    {
  46       .orig_file = NULL,
  47       .static_src =
  48
  49         "out vec4 FragColor;"
  50         ""
  51         "in vec4 s_colour;"
  52         ""
  53         "void main()"
  54         "{"
  55         "       FragColor = s_colour;"
  56         "}"
  57    }
  58 };
  59
  60
  61 struct
  62 {
  63    u32 draw,
  64        allow_input;
  65
  66    struct vg_lines_vert
  67    {
  68       v3f co;
  69       u32 colour;
  70    }
  71    *vertex_buffer;
  72
  73         GLuint vao, vbo;
  74 }
  75 static vg_lines;
  76
  77 VG_STATIC void vg_lines_init(void)
  78 {
  79    vg_info( "vg_lines_init\n" );
  80
  81    vg_var_push( (struct vg_var){
  82       .name = "vg_lines",
  83       .data = &vg_lines.draw,
  84       .data_type = k_var_dtype_i32,
  85       .opt_i32 = { .min=0, .max=1, .clamp=1 },
  86       .persistent = 1
  87    });
  88
  89    vg_shader_register( &_shader_lines );
  90
  91    vg_acquire_thread_sync();
  92    {
  93       glGenVertexArrays( 1, &vg_lines.vao );
  94       glGenBuffers( 1, &vg_lines.vbo );
  95       glBindVertexArray( vg_lines.vao );
  96       glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  97
  98       u32 size = 50000 * sizeof( struct vg_lines_vert );
  99
 100       vg_lines.vertex_buffer =
 101          vg_create_linear_allocator(vg_mem.rtmemory, size, VG_MEMORY_REALTIME);
 102
 103       glBufferData( GL_ARRAY_BUFFER, size, NULL, GL_DYNAMIC_DRAW );
 104       glBindVertexArray( vg_lines.vao );
 105       VG_CHECK_GL_ERR();
 106
 107       /* Pointers */
 108       glVertexAttribPointer(
 109          0,
 110          3,
 111          GL_FLOAT,
 112          GL_FALSE,
 113          sizeof( struct vg_lines_vert ),
 114          (void *)0
 115       );
 116       glEnableVertexAttribArray( 0 );
 117
 118       glVertexAttribPointer(
 119          1,
 120          4,
 121          GL_UNSIGNED_BYTE,
 122          GL_TRUE,
 123          sizeof( struct vg_lines_vert ),
 124          (void*)(offsetof( struct vg_lines_vert, colour ))
 125       );
 126       glEnableVertexAttribArray( 1 );
 127
 128       VG_CHECK_GL_ERR();
 129       vg_success( "done\n" );
 130    }
 131
 132    vg_release_thread_sync();
 133    vg_lines.allow_input = 1;
 134 }
 135
 136 VG_STATIC void vg_lines_drawall( void )
 137 {
 138         glUseProgram( _shader_lines.id );
 139
 140    glUniformMatrix4fv( glGetUniformLocation( _shader_lines.id, "uPv" ),
 141      1, GL_FALSE, (float *)vg.pv );
 142
 143         glBindVertexArray( vg_lines.vao );
 144         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 145
 146    u32 bufusage = vg_linear_get_cur(vg_lines.vertex_buffer);
 147
 148         glBufferSubData( GL_ARRAY_BUFFER, 0, bufusage, vg_lines.vertex_buffer );
 149
 150         glEnable( GL_BLEND );
 151         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 152         glBlendEquation( GL_FUNC_ADD );
 153
 154    if( vg_lines.draw )
 155       glDrawArrays( GL_LINES, 0, bufusage / sizeof(struct vg_lines_vert) );
 156
 157         glDisable( GL_BLEND );
 158    vg_linear_clear( vg_lines.vertex_buffer );
 159 }
 160
 161 VG_STATIC void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 162 {
 163    if( !vg_lines.allow_input )
 164       return;
 165
 166    u32 size = 2 * sizeof(struct vg_lines_vert);
 167         struct vg_lines_vert *v = vg_linear_alloc( vg_lines.vertex_buffer, size );
 168
 169         v3_copy( from, v[0].co );
 170         v3_copy( to, v[1].co );
 171
 172         v[0].colour = fc;
 173         v[1].colour = tc;
 174 }
 175
 176 VG_STATIC void vg_line( line_co from, line_co to, u32 colour )
 177 {
 178         vg_line2( from, to, colour, colour );
 179 }
 180
 181 VG_STATIC void line_tangent_basis( v3f n, v3f tx, v3f ty )
 182 {
 183    /* Compute tangent basis (box2d) */
 184    if( fabsf( n[0] ) >= 0.57735027f )
 185    {
 186       tx[0] =  n[1];
 187       tx[1] = -n[0];
 188       tx[2] =  0.0f;
 189    }
 190    else
 191    {
 192       tx[0] =  0.0f;
 193       tx[1] =  n[2];
 194       tx[2] = -n[1];
 195    }
 196
 197    v3_normalize( tx );
 198    v3_cross( n, tx, ty );
 199 }
 200
 201 VG_STATIC void vg_line_arrow( line_co co, line_co dir, float size, u32 colour )
 202 {
 203    v3f p1, tx, ty, p2, p3;
 204    v3_muladds( co, dir, size, p1 );
 205    line_tangent_basis( dir, tx, ty );
 206
 207    v3_muladds( p1, dir, -size * 0.125f, p2 );
 208    v3_muladds( p2, ty,  size * 0.125f, p3 );
 209    v3_muladds( p2, ty, -size * 0.125f, p2 );
 210
 211    vg_line( co, p1, colour );
 212    vg_line( p1, p2, colour );
 213    vg_line( p1, p3, colour );
 214 }
 215
 216 VG_STATIC void vg_line_boxf( boxf box, u32 colour )
 217 {
 218    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 219
 220    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 221    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 222    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 223    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 224
 225    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 226    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 227    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 228    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 229
 230    vg_line( p000, p001, colour );
 231    vg_line( p001, p011, colour );
 232    vg_line( p011, p010, colour );
 233    vg_line( p010, p000, colour );
 234
 235    vg_line( p100, p101, colour );
 236    vg_line( p101, p111, colour );
 237    vg_line( p111, p110, colour );
 238    vg_line( p110, p100, colour );
 239
 240    vg_line( p100, p000, colour );
 241    vg_line( p101, p001, colour );
 242    vg_line( p110, p010, colour );
 243    vg_line( p111, p011, colour );
 244 }
 245
 246 VG_STATIC void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour )
 247 {
 248    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 249
 250    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 251    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 252    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 253    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 254
 255    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 256    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 257    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 258    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 259
 260    m4x3_mulv( m, p000, p000 );
 261    m4x3_mulv( m, p001, p001 );
 262    m4x3_mulv( m, p010, p010 );
 263    m4x3_mulv( m, p011, p011 );
 264    m4x3_mulv( m, p100, p100 );
 265    m4x3_mulv( m, p101, p101 );
 266    m4x3_mulv( m, p110, p110 );
 267    m4x3_mulv( m, p111, p111 );
 268
 269    vg_line( p000, p001, colour );
 270    vg_line( p001, p011, colour );
 271    vg_line( p011, p010, colour );
 272    vg_line( p010, p000, colour );
 273
 274    vg_line( p100, p101, colour );
 275    vg_line( p101, p111, colour );
 276    vg_line( p111, p110, colour );
 277    vg_line( p110, p100, colour );
 278
 279    vg_line( p100, p000, colour );
 280    vg_line( p101, p001, colour );
 281    vg_line( p110, p010, colour );
 282    vg_line( p111, p011, colour );
 283
 284    vg_line( p000, p110, colour );
 285    vg_line( p100, p010, colour );
 286 }
 287
 288 VG_STATIC void vg_line_cross(v3f pos,u32 colour, float scale)
 289 {
 290    v3f p0, p1;
 291    v3_add( (v3f){ scale,0.0f,0.0f}, pos, p0 );
 292    v3_add( (v3f){-scale,0.0f,0.0f}, pos, p1 );
 293    vg_line( p0, p1, colour );
 294    v3_add( (v3f){0.0f, scale,0.0f}, pos, p0 );
 295    v3_add( (v3f){0.0f,-scale,0.0f}, pos, p1 );
 296    vg_line( p0, p1, colour );
 297    v3_add( (v3f){0.0f,0.0f, scale}, pos, p0 );
 298    v3_add( (v3f){0.0f,0.0f,-scale}, pos, p1 );
 299    vg_line( p0, p1, colour );
 300 }
 301
 302 VG_STATIC void vg_line_pt3( v3f pt, float size, u32 colour )
 303 {
 304    boxf box =
 305    {
 306       { pt[0]-size, pt[1]-size, pt[2]-size },
 307       { pt[0]+size, pt[1]+size, pt[2]+size }
 308    };
 309
 310    vg_line_boxf( box, colour );
 311 }
 312
 313 #endif /* VG_LINES_H */