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 SHADER_DEFINE( vg_line_shader,
  12 #ifdef VG_3D
  13         "uniform mat4 uPv;"
  14         "layout (location=0) in vec3 a_co;"
  15 #else
  16         "uniform mat3 uPv;"
  17         "layout (location=0) in vec2 a_co;"
  18 #endif
  19         "layout (location=1) in vec4 a_colour;"
  20         ""
  21         "out vec4 s_colour;"
  22         ""
  23         "void main()"
  24         "{"
  25 #ifdef VG_3D
  26         "       vec4 vert_pos = uPv * vec4( a_co, 1.0 );"
  27 #else
  28         "       vec4 vert_pos = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
  29 #endif
  30         "  s_colour = a_colour;"
  31         "       gl_Position = vert_pos;"
  32         "}",
  33
  34         // FRAGMENT
  35         "out vec4 FragColor;"
  36         ""
  37         "in vec4 s_colour;"
  38         ""
  39         "void main()"
  40         "{"
  41         "       FragColor = s_colour;"
  42         "}"
  43         ,
  44         UNIFORMS({ "uPv" })
  45 )
  46
  47 struct
  48 {
  49         struct vg_lines_vert
  50         {
  51 #ifdef VG_3D
  52       v3f co;
  53 #else
  54                 v2f co;
  55 #endif
  56
  57                 u32 colour;
  58         }
  59         *buffer;
  60
  61         GLuint vao, vbo;
  62         u32 draw_idx, cap, buffer_size;
  63 }
  64 vg_lines;
  65
  66 static void vg_lines_init(void)
  67 {
  68    vg_convar_push( (struct vg_convar){
  69       .name = "debug_lines",
  70       .data = &debug_lines_enable,
  71       .data_type = k_convar_dtype_i32,
  72       .opt_i32 = { .min=0, .max=1, .clamp=1 },
  73       .persistent = 1
  74    });
  75
  76         SHADER_INIT( vg_line_shader );
  77
  78         glGenVertexArrays( 1, &vg_lines.vao );
  79         glGenBuffers( 1, &vg_lines.vbo );
  80         glBindVertexArray( vg_lines.vao );
  81
  82         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
  83
  84         vg_lines.cap = 50000;
  85         vg_lines.buffer_size = vg_lines.cap * sizeof( struct vg_lines_vert );
  86
  87         glBufferData( GL_ARRAY_BUFFER, vg_lines.buffer_size, NULL, GL_DYNAMIC_DRAW );
  88         glBindVertexArray( vg_lines.vao );
  89
  90         glVertexAttribPointer(
  91                 0,
  92                 sizeof( vg_lines.buffer[0].co ) / sizeof(float),
  93                 GL_FLOAT,
  94                 GL_FALSE,
  95                 sizeof( struct vg_lines_vert ),
  96                 (void *)0
  97         );
  98         glEnableVertexAttribArray( 0 );
  99
 100         glVertexAttribPointer(
 101                 1,
 102                 4,
 103                 GL_UNSIGNED_BYTE,
 104                 GL_TRUE,
 105                 sizeof( struct vg_lines_vert ),
 106                 (void*)(offsetof( struct vg_lines_vert, colour ))
 107         );
 108         glEnableVertexAttribArray( 1 );
 109         vg_lines.buffer = malloc( vg_lines.buffer_size );
 110 }
 111
 112 static void vg_lines_free(void)
 113 {
 114         glDeleteVertexArrays( 1, &vg_lines.vao );
 115         glDeleteBuffers( 1, &vg_lines.vbo );
 116
 117         free( vg_lines.buffer );
 118 }
 119
 120 static void vg_lines_drawall( float* projection )
 121 {
 122         SHADER_USE( vg_line_shader );
 123
 124 #ifdef VG_3D
 125    glUniformMatrix4fv
 126 #else
 127         glUniformMatrix3fv
 128 #endif
 129    ( SHADER_UNIFORM( vg_line_shader, "uPv" ), 1, GL_FALSE, projection );
 130
 131         glBindVertexArray( vg_lines.vao );
 132         glBindBuffer( GL_ARRAY_BUFFER, vg_lines.vbo );
 133
 134         glBufferSubData( GL_ARRAY_BUFFER, 0, vg_lines.draw_idx *
 135          sizeof(struct vg_lines_vert), vg_lines.buffer );
 136
 137         glEnable( GL_BLEND );
 138         glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 139         glBlendEquation( GL_FUNC_ADD );
 140
 141    if( debug_lines_enable )
 142       glDrawArrays( GL_LINES, 0, vg_lines.draw_idx );
 143
 144         glDisable( GL_BLEND );
 145         vg_lines.draw_idx = 0;
 146 }
 147
 148 static void vg_line2( line_co from, line_co to, u32 fc, u32 tc )
 149 {
 150         struct vg_lines_vert *v = &vg_lines.buffer[vg_lines.draw_idx];
 151
 152 #ifdef VG_3D
 153         v3_copy( from, v[0].co );
 154         v3_copy( to, v[1].co );
 155 #else
 156         v2_copy( from, v[0].co );
 157         v2_copy( to, v[1].co );
 158 #endif
 159
 160         v[0].colour = fc;
 161         v[1].colour = tc;
 162
 163         vg_lines.draw_idx += 2;
 164 }
 165
 166 static void vg_line( line_co from, line_co to, u32 colour )
 167 {
 168         vg_line2( from, to, colour, colour );
 169 }
 170
 171 static void vg_line_box( line_co min, line_co max, u32 colour )
 172 {
 173 #ifdef VG_3D
 174    /* TODO... */
 175 #else
 176         vg_line( min, (v2f){min[0],max[1]}, colour );
 177         vg_line( (v2f){min[0],max[1]}, max, colour );
 178         vg_line( max, (v2f){max[0],min[1]}, colour );
 179         vg_line( (v2f){max[0],min[1]}, min, colour );
 180 #endif
 181 }
 182
 183 static void vg_line_boxf( boxf box, u32 colour )
 184 {
 185    v3f p000, p001, p010, p011, p100, p101, p110, p111;
 186
 187    p000[0]=box[0][0];p000[1]=box[0][1];p000[2]=box[0][2];
 188    p001[0]=box[0][0];p001[1]=box[0][1];p001[2]=box[1][2];
 189    p010[0]=box[0][0];p010[1]=box[1][1];p010[2]=box[0][2];
 190    p011[0]=box[0][0];p011[1]=box[1][1];p011[2]=box[1][2];
 191
 192    p100[0]=box[1][0];p100[1]=box[0][1];p100[2]=box[0][2];
 193    p101[0]=box[1][0];p101[1]=box[0][1];p101[2]=box[1][2];
 194    p110[0]=box[1][0];p110[1]=box[1][1];p110[2]=box[0][2];
 195    p111[0]=box[1][0];p111[1]=box[1][1];p111[2]=box[1][2];
 196
 197    vg_line( p000, p001, colour );
 198    vg_line( p001, p011, colour );
 199    vg_line( p011, p010, colour );
 200    vg_line( p010, p000, colour );
 201
 202    vg_line( p100, p101, colour );
 203    vg_line( p101, p111, colour );
 204    vg_line( p111, p110, colour );
 205    vg_line( p110, p100, colour );
 206
 207    vg_line( p100, p000, colour );
 208    vg_line( p101, p001, colour );
 209    vg_line( p110, p010, colour );
 210    vg_line( p111, p011, colour );
 211 }
 212
 213 static void vg_line_pt3( v3f pt, float size, u32 colour )
 214 {
 215    boxf box =
 216    {
 217       { pt[0]-size, pt[1]-size, pt[2]-size },
 218       { pt[0]+size, pt[1]+size, pt[2]+size }
 219    };
 220
 221    vg_line_boxf( box, colour );
 222 }