vg/vg_ui.h

   1 // Copyright (C) 2021 Harry Godden (hgn) - All Rights Reserved
   2 /*
   3
   4         Concurrent UI buffer system
   5         Coordinate space:
   6
   7    0,0 --- +(res:x)
   8          |
   9          |
  10          |
  11 +(res:y)
  12
  13 */
  14
  15 #define UI_AUTO_FILL 0
  16
  17 // Types
  18 // ================================================================
  19 typedef i16                             ui_px;
  20 typedef u32                             ui_colour;
  21 typedef ui_px                           ui_rect[4];
  22 typedef struct ui_ctx   ui_ctx;
  23
  24 struct ui_ctx
  25 {
  26         ui_px padding;
  27
  28         struct ui_qnode
  29         {
  30                 ui_rect                 rect;
  31                 ui_colour       colour;
  32                 int                     mouse_over;
  33                 int                     capture_id;
  34         }
  35         stack[ 32 ];
  36
  37         ui_rect cursor;
  38         u32 stack_count;
  39         u32 capture_mouse_id;
  40
  41         // User input
  42         ui_px mouse[2];
  43         int click_state;        // 0: released, 1: on down, 2: pressed, 3: on release
  44 };
  45
  46 // Rect controls
  47 // ==========================================================
  48
  49 static void ui_rect_copy( ui_rect src, ui_rect dst )
  50 {
  51         dst[0] = src[0];
  52         dst[1] = src[1];
  53         dst[2] = src[2];
  54         dst[3] = src[3];
  55 }
  56
  57 static void ui_rect_pad( ui_ctx *ctx, ui_rect rect )
  58 {
  59         rect[0] += ctx->padding;
  60         rect[1] += ctx->padding;
  61         rect[2] -= ctx->padding*2;
  62         rect[3] -= ctx->padding*2;
  63 }
  64
  65 static void ui_vis_rect( ui_rect rect, u32 colour )
  66 {
  67         v2f p0;
  68         v2f p1;
  69
  70         p0[0] = rect[0];
  71         p0[1] = rect[1];
  72         p1[0] = rect[0]+rect[2];
  73         p1[1] = rect[1]+rect[3];
  74
  75         vg_line( p0, (v2f){p1[0],p0[1]}, colour );
  76         vg_line( (v2f){p1[0],p0[1]}, p1, colour );
  77         vg_line( p1, (v2f){p0[0],p1[1]}, colour );
  78         vg_line( (v2f){p0[0],p1[1]}, p0, colour );
  79 }
  80
  81 static void ui_new_node( ui_ctx *ctx )
  82 {
  83         if( ctx->stack_count == vg_list_size( ctx->stack ) )
  84                 vg_exiterr( "[UI] Stack overflow while creating box!" );
  85
  86         struct ui_qnode *parent = &ctx->stack[ ctx->stack_count-1 ];
  87         struct ui_qnode *node = &ctx->stack[ ctx->stack_count++ ];
  88         ui_rect_copy( ctx->cursor, node->rect );
  89
  90         if( parent->mouse_over )
  91         {
  92                 if( ctx->mouse[0] >= node->rect[0] && ctx->mouse[0] <= node->rect[0]+node->rect[2] &&
  93                          ctx->mouse[1] >= node->rect[1] && ctx->mouse[1] <= node->rect[1]+node->rect[3] )
  94                         node->mouse_over = 1;
  95                 else
  96                         node->mouse_over = 0;
  97         }
  98 }
  99
 100 static int ui_hasmouse( ui_ctx *ctx )
 101 {
 102         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 103         return (node->mouse_over && (node->capture_id == ctx->capture_mouse_id));
 104 }
 105
 106 static void ui_end( ui_ctx *ctx )
 107 {
 108         struct ui_qnode *node = &ctx->stack[ --ctx->stack_count ];
 109
 110         ui_rect_copy( node->rect, ctx->cursor );
 111         ui_vis_rect( ctx->cursor, (node->mouse_over && (node->capture_id == ctx->capture_mouse_id))? 0xffff0000: 0xff0000ff );
 112 }
 113
 114 static void ui_end_down( ui_ctx *ctx )
 115 {
 116         ui_px height = ctx->stack[ ctx->stack_count ].rect[3];
 117         ui_end( ctx );
 118         ctx->cursor[1] += height;
 119 }
 120
 121 static void ui_end_right( ui_ctx *ctx )
 122 {
 123         ui_px width = ctx->stack[ ctx->stack_count ].rect[2];
 124         ui_end( ctx );
 125         ctx->cursor[0] += width;
 126 }
 127
 128 static void ui_capture_mouse( ui_ctx *ctx, int id )
 129 {
 130         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 131         node->capture_id = id;
 132
 133         if( node->mouse_over )
 134         {
 135                 ctx->capture_mouse_id = id;
 136         }
 137 }
 138
 139 // API control
 140 // ====================================================================
 141
 142 static void ui_begin( ui_ctx *ctx, ui_px res_x, ui_px res_y )
 143 {
 144         ctx->cursor[0] = 0;
 145         ctx->cursor[1] = 0;
 146         ctx->cursor[2] = res_x;
 147         ctx->cursor[3] = res_y;
 148
 149         ui_rect_copy( ctx->cursor, ctx->stack[0].rect );
 150         ctx->stack[0].mouse_over = 1;
 151
 152         ctx->stack_count = 1;
 153 }
 154
 155 static void ui_resolve( ui_ctx *ctx )
 156 {
 157         if( ctx->stack_count-1 )
 158                 vg_exiterr( "[UI] Mismatched node create/drestroy!" );
 159 }
 160
 161 // User Input piping
 162 // ====================================================================
 163
 164 static void ui_set_mouse( ui_ctx *ctx, int x, int y, int click_state )
 165 {
 166         ctx->mouse[0] = x;
 167         ctx->mouse[1] = y;
 168
 169         ctx->click_state = click_state;
 170 }
 171
 172 static void ui_test(void)
 173 {
 174         /*
 175                 +------------------------------------------------------+
 176                 | Central Market                                    [x]|
 177                 +------+--------------+-+------------------------------+
 178                 | Buy  | Balance      |#| [filters] [favorites]        |
 179                 | <>_  | () 2,356     |#|----------------------------+-+
 180                 |------|--------------|#| [] potion of madness     4 |#|
 181                 | Sell | \ Main sword |#|----------------------------|#|
 182                 | _*^  |--------------|#| [] Balance of time      23 | |
 183                 |------| * Side arm   |#|----------------------------| |
 184                 | 235  |--------------| | [] Strength          5,300 | |
 185                 |      | () Sheild    | |----------------------------| |
 186                 |      |--------------| | [] Bewilder          2,126 | |
 187                 |      [ & Spells     ] |----------------------------| |
 188                 |      |--------------| | [] Eternal flames        6 | |
 189                 +------+--------------+-+----------------------------+-+
 190         */
 191
 192         ui_ctx ctx = { .padding = 8 };
 193
 194         ui_begin( &ctx, vg_window_x, vg_window_y );
 195
 196         // TODO: Find a more elegent form for this
 197         int mouse_state = 0;
 198         if( vg_get_button( "primary" ) ) mouse_state = 2;
 199         if( vg_get_button_down( "primary" ) ) mouse_state = 1;
 200         if( vg_get_button_up( "primary" ) ) mouse_state = 3;
 201
 202         ui_set_mouse( &ctx, vg_mouse[0], vg_mouse[1], mouse_state );
 203
 204         static ui_px window_x = 20;
 205         static ui_px window_y = 20;
 206         static int window_drag = 0;
 207         static ui_px drag_offset[2];
 208
 209         if( window_drag )
 210         {
 211                 window_x = ctx.mouse[0]+drag_offset[0];
 212                 window_y = ctx.mouse[1]+drag_offset[1];
 213
 214                 if( ctx.click_state == 0 )
 215                 {
 216                         window_drag = 0;
 217                 }
 218         }
 219
 220         ctx.cursor[0] = window_x;
 221         ctx.cursor[1] = window_y;
 222         ctx.cursor[2] = 500;
 223         ctx.cursor[3] = 350;
 224
 225         ui_new_node( &ctx );
 226         {
 227                 ctx.cursor[0] += 20;
 228                 ctx.cursor[1] += 20;
 229                 ctx.cursor[2] = 150;
 230                 ctx.cursor[3] = 25;
 231
 232                 ui_capture_mouse( &ctx, 1 );
 233
 234                 ui_new_node( &ctx );
 235                 {
 236                         ui_capture_mouse( &ctx, 2 );
 237
 238                         if( ui_hasmouse( &ctx ) )
 239                         {
 240                                 if( ctx.click_state == 1 ) // start drag
 241                                 {
 242                                         window_drag = 1;
 243                                         drag_offset[0] = window_x-ctx.mouse[0];
 244                                         drag_offset[1] = window_y-ctx.mouse[1];
 245                                 }
 246                         }
 247                 }
 248                 ui_end( &ctx );
 249         }
 250         ui_end( &ctx );
 251
 252         ui_resolve( &ctx );
 253
 254         m3x3f view = M3X3_IDENTITY;
 255         m3x3_translate( view, (v3f){ -1.0f, 1.0f, 0.0f } );
 256         m3x3_scale( view, (v3f){ 1.0f/((float)vg_window_x*0.5f), -1.0f/((float)vg_window_y*0.5f), 1.0f } );
 257         vg_lines_drawall( (float*)view );
 258 }