src/vg/vg_lines.h

   1 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
   2
   3 static int debug_lines_enable = 1;
   4
   5 #ifdef VG_3D
   6  typedef v3f line_co;
   7 #else
   8  typedef v2f line_co;
   9 #endif
  10
  11 static struct vg_shader _shader_lines =
  12 {
  13    .name = "[vg] lines",
  14    .link = NULL,
  15    .vs =
  16    {
  17       .orig_file = NULL,
  18       .static_src =
  19
  20 #ifdef VG_3D
  21         "uniform mat4 uPv;"
  22         "layout (location=0) in vec3 a_co;"
  23 #else
  24         "uniform mat3 uPv;"
  25         "layout (location=0) in vec2 a_co;"
  26 #endif
  27         "layout (location=1) in vec4 a_colour;"
  28         ""
  29         "out vec4 s_colour;"
  30         ""
  31         "void main()"
  32         "{"
  33 #ifdef VG_3D
  34         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  35 #else
  36         "       vec4 vert_pos = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
  37 #endif
  38         "  s_colour = a_colour;"
  39         "       gl_Position = vert_pos;"
  40         "}"
  41    },
  42    .fs =
  43    {
  44       .orig_file = NULL,
  45       .static_src =
  46
  47         "out vec4 FragColor;"
  48         ""
  49         "in vec4 s_colour;"
  50         ""
  51         "void main()"
  52         "{"
  53         "       FragColor = s_colour;"
  54         "}"
  55    }
  56 };
  57
  58 struct
  59 {
  60         struct vg_lines_vert
  61         {
  62 #ifdef VG_3D
  63       v3f co;
  64 #else
  65                 v2f co;
  66 #endif
  67
  68                 u32 colour;
  69         }
  70         *buffer;
  71
  72         GLuint vao, vbo;
  73         u32 draw_idx, cap, buffer_size;
  74 }
  75 vg_lines;
  76
  77 static void vg_lines_init(void)
  78 {
  79    vg_convar_push( (struct vg_convar){
  80       .name = "debug_lines",
  81       .data = &debug_lines_enable,
  82       .data_type = k_convar_dtype_i32,
  83       .opt_i32 = { .min=0, .max=1, .clamp=1 },
  84       .persistent = 1
  85    });
  86
  87    vg_shader_register( &_shader_lines );
  88
  89         glGenVertexArrays( 1, &vg_lines.vao );
  90         glGenBuffers( 1, &vg_lines.vbo );
  91         glBindVertexArray( vg_lines.vao );
  92
  93         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  94
  95         vg_lines.cap = 50000;
  96         vg_lines.buffer_size = vg_lines.cap * sizeof( struct vg_lines_vert );
  97
  98         glBufferData( GL_ARRAY_BUFFER, vg_lines.buffer_size, NULL, GL_DYNAMIC_DRAW );
  99         glBindVertexArray( vg_lines.vao );
 100
 101         glVertexAttribPointer(
 102                 0,
 103                 sizeof( vg_lines.buffer[0].co ) / sizeof(float),
 104                 GL_FLOAT,
 105                 GL_FALSE,
 106                 sizeof( struct vg_lines_vert ),
 107                 (void *)0
 108         );
 109         glEnableVertexAttribArray( 0 );
 110
 111         glVertexAttribPointer(
 112                 1,
 113                 4,
 114                 GL_UNSIGNED_BYTE,
 115                 GL_TRUE,
 116                 sizeof( struct vg_lines_vert ),
 117                 (void*)(offsetof( struct vg_lines_vert, colour ))
 118         );
 119         glEnableVertexAttribArray( 1 );
 120         vg_lines.buffer = malloc( vg_lines.buffer_size );
 121 }
 122
 123 static void vg_lines_free(void)
 124 {
 125         glDeleteVertexArrays( 1, &vg_lines.vao );
 126         glDeleteBuffers( 1, &vg_lines.vbo );
 127
 128         free( vg_lines.buffer );
 129 }
 130
 131 static void vg_lines_drawall( float* projection )
 132 {
 133         glUseProgram( _shader_lines.id );
 134
 135 #ifdef VG_3D
 136    glUniformMatrix4fv
 137 #else
 138         glUniformMatrix3fv
 139 #endif
 140    ( glGetUniformLocation( _shader_lines.id, "uPv" ), 1, GL_FALSE, projection );
 141
 142         glBindVertexArray( vg_lines.vao );
 143         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 144
 145         glBufferSubData( GL_ARRAY_BUFFER, 0, vg_lines.draw_idx *
 146          sizeof(struct vg_lines_vert), vg_lines.buffer );
 147
 148         glEnable( GL_BLEND );
 149         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 150         glBlendEquation( GL_FUNC_ADD );
 151
 152    if( debug_lines_enable )
 153       glDrawArrays( GL_LINES, 0, vg_lines.draw_idx );
 154
 155         glDisable( GL_BLEND );
 156         vg_lines.draw_idx = 0;
 157 }
 158
 159 static void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 160 {
 161         struct vg_lines_vert *v = &vg_lines.buffer[vg_lines.draw_idx];
 162
 163 #ifdef VG_3D
 164         v3_copy( from, v[0].co );
 165         v3_copy( to, v[1].co );
 166 #else
 167         v2_copy( from, v[0].co );
 168         v2_copy( to, v[1].co );
 169 #endif
 170
 171         v[0].colour = fc;
 172         v[1].colour = tc;
 173
 174         vg_lines.draw_idx += 2;
 175 }
 176
 177 static void vg_line( line_co from, line_co to, u32 colour )
 178 {
 179         vg_line2( from, to, colour, colour );
 180 }
 181
 182 static void vg_line_box( line_co min, line_co max, u32 colour )
 183 {
 184 #ifdef VG_3D
 185    /* TODO... */
 186 #else
 187         vg_line( min, (v2f){min[0],max[1]}, colour );
 188         vg_line( (v2f){min[0],max[1]}, max, colour );
 189         vg_line( max, (v2f){max[0],min[1]}, colour );
 190         vg_line( (v2f){max[0],min[1]}, min, colour );
 191 #endif
 192 }
 193
 194 static void vg_line_boxf( boxf box, u32 colour )
 195 {
 196    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 197
 198    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 199    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 200    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 201    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 202
 203    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 204    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 205    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 206    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 207
 208    vg_line( p000, p001, colour );
 209    vg_line( p001, p011, colour );
 210    vg_line( p011, p010, colour );
 211    vg_line( p010, p000, colour );
 212
 213    vg_line( p100, p101, colour );
 214    vg_line( p101, p111, colour );
 215    vg_line( p111, p110, colour );
 216    vg_line( p110, p100, colour );
 217
 218    vg_line( p100, p000, colour );
 219    vg_line( p101, p001, colour );
 220    vg_line( p110, p010, colour );
 221    vg_line( p111, p011, colour );
 222 }
 223
 224 static void vg_line_boxf_transformed( m4x3f m, boxf box, u32 colour )
 225 {
 226    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 227
 228    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 229    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 230    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 231    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 232
 233    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 234    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 235    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 236    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 237
 238    m4x3_mulv( m, p000, p000 );
 239    m4x3_mulv( m, p001, p001 );
 240    m4x3_mulv( m, p010, p010 );
 241    m4x3_mulv( m, p011, p011 );
 242    m4x3_mulv( m, p100, p100 );
 243    m4x3_mulv( m, p101, p101 );
 244    m4x3_mulv( m, p110, p110 );
 245    m4x3_mulv( m, p111, p111 );
 246
 247    vg_line( p000, p001, colour );
 248    vg_line( p001, p011, colour );
 249    vg_line( p011, p010, colour );
 250    vg_line( p010, p000, colour );
 251
 252    vg_line( p100, p101, colour );
 253    vg_line( p101, p111, colour );
 254    vg_line( p111, p110, colour );
 255    vg_line( p110, p100, colour );
 256
 257    vg_line( p100, p000, colour );
 258    vg_line( p101, p001, colour );
 259    vg_line( p110, p010, colour );
 260    vg_line( p111, p011, colour );
 261
 262    vg_line( p000, p110, colour );
 263    vg_line( p100, p010, colour );
 264 }
 265
 266 static void vg_line_pt3( v3f pt, float size, u32 colour )
 267 {
 268    boxf box =
 269    {
 270       { pt[0]-size, pt[1]-size, pt[2]-size },
 271       { pt[0]+size, pt[1]+size, pt[2]+size }
 272    };
 273
 274    vg_line_boxf( box, colour );
 275 }