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         int capture_lock;
  41         u32 id_base;
  42
  43         // User input
  44         ui_px mouse[2];
  45         int click_state;        // 0: released, 1: on down, 2: pressed, 3: on release
  46 };
  47
  48 // Rect controls
  49 // ==========================================================
  50
  51 static void ui_rect_copy( ui_rect src, ui_rect dst )
  52 {
  53         dst[0] = src[0];
  54         dst[1] = src[1];
  55         dst[2] = src[2];
  56         dst[3] = src[3];
  57 }
  58
  59 static void ui_rect_pad( ui_ctx *ctx, ui_rect rect, ui_px pad )
  60 {
  61         rect[0] += pad;
  62         rect[1] += pad;
  63         rect[2] -= pad*2;
  64         rect[3] -= pad*2;
  65 }
  66
  67 static void ui_vis_rect( ui_rect rect, u32 colour )
  68 {
  69         v2f p0;
  70         v2f p1;
  71
  72         p0[0] = rect[0];
  73         p0[1] = rect[1];
  74         p1[0] = rect[0]+rect[2];
  75         p1[1] = rect[1]+rect[3];
  76
  77         vg_line( p0, (v2f){p1[0],p0[1]}, colour );
  78         vg_line( (v2f){p1[0],p0[1]}, p1, colour );
  79         vg_line( p1, (v2f){p0[0],p1[1]}, colour );
  80         vg_line( (v2f){p0[0],p1[1]}, p0, colour );
  81 }
  82
  83 static void ui_new_node( ui_ctx *ctx )
  84 {
  85         if( ctx->stack_count == vg_list_size( ctx->stack ) )
  86                 vg_exiterr( "[UI] Stack overflow while creating box!" );
  87
  88         struct ui_qnode *parent = &ctx->stack[ ctx->stack_count-1 ];
  89         struct ui_qnode *node = &ctx->stack[ ctx->stack_count++ ];
  90         ui_rect_copy( ctx->cursor, node->rect );
  91
  92         if( parent->mouse_over )
  93         {
  94                 if( ctx->mouse[0] >= node->rect[0] && ctx->mouse[0] <= node->rect[0]+node->rect[2] &&
  95                          ctx->mouse[1] >= node->rect[1] && ctx->mouse[1] <= node->rect[1]+node->rect[3] )
  96                         node->mouse_over = 1;
  97                 else
  98                         node->mouse_over = 0;
  99         }
 100         else
 101         {
 102                 node->mouse_over = 0;
 103         }
 104 }
 105
 106 static int ui_hasmouse( ui_ctx *ctx )
 107 {
 108         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 109         return (node->mouse_over && (node->capture_id == ctx->capture_mouse_id));
 110 }
 111
 112 static void ui_end( ui_ctx *ctx )
 113 {
 114         struct ui_qnode *node = &ctx->stack[ --ctx->stack_count ];
 115
 116         ui_rect_copy( node->rect, ctx->cursor );
 117         ui_vis_rect( ctx->cursor, (node->mouse_over && (node->capture_id == ctx->capture_mouse_id))? 0xffff0000: 0xff0000ff );
 118 }
 119
 120 static void ui_end_down( ui_ctx *ctx )
 121 {
 122         ui_px height = ctx->stack[ ctx->stack_count ].rect[3];
 123         ui_end( ctx );
 124         ctx->cursor[1] += height;
 125 }
 126
 127 static void ui_end_right( ui_ctx *ctx )
 128 {
 129         ui_px width = ctx->stack[ ctx->stack_count ].rect[2];
 130         ui_end( ctx );
 131         ctx->cursor[0] += width;
 132 }
 133
 134 static void ui_align_right( ui_ctx *ctx )
 135 {
 136         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 137         ctx->cursor[0] = node->rect[0] + node->rect[2] - ctx->cursor[2];
 138 }
 139
 140 static void ui_clamp_rect( ui_rect parent, ui_rect dest )
 141 {
 142         dest[0] = vg_min( parent[0] + parent[2] - dest[2], dest[0] );
 143         dest[1] = vg_min( parent[1] + parent[3] - dest[3], dest[1] );
 144         dest[0] = vg_max( parent[0], dest[0] );
 145         dest[1] = vg_max( parent[1], dest[1] );
 146 }
 147
 148 static u32 ui_group_id( ui_ctx *ctx, u32 lesser_unique )
 149 {
 150         return ctx->id_base | lesser_unique;
 151 }
 152
 153 static void ui_capture_mouse( ui_ctx *ctx, u32 id )
 154 {
 155         u32 group_uid = ui_group_id(ctx,id);
 156
 157         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 158         node->capture_id = group_uid;
 159
 160         if( !ctx->capture_lock && node->mouse_over )
 161         {
 162                 ctx->capture_mouse_id = group_uid;
 163         }
 164 }
 165
 166 // API control
 167 // ====================================================================
 168
 169 static void ui_begin( ui_ctx *ctx, ui_px res_x, ui_px res_y )
 170 {
 171         ctx->cursor[0] = 0;
 172         ctx->cursor[1] = 0;
 173         ctx->cursor[2] = res_x;
 174         ctx->cursor[3] = res_y;
 175
 176         ui_rect_copy( ctx->cursor, ctx->stack[0].rect );
 177         ctx->stack[0].mouse_over = 1;
 178
 179         ctx->stack_count = 1;
 180 }
 181
 182 static void ui_resolve( ui_ctx *ctx )
 183 {
 184         if( ctx->stack_count-1 )
 185                 vg_exiterr( "[UI] Mismatched node create/drestroy!" );
 186
 187         if( ctx->click_state == 3 || ctx->click_state == 0 )
 188         {
 189                 ctx->capture_lock = 0;
 190         }
 191 }
 192
 193 // User Input piping
 194 // ====================================================================
 195
 196 static void ui_set_mouse( ui_ctx *ctx, int x, int y, int click_state )
 197 {
 198         ctx->mouse[0] = x;
 199         ctx->mouse[1] = y;
 200
 201         ctx->click_state = click_state;
 202 }
 203
 204 // High level controls
 205 // ====================================================================
 206
 207 struct ui_window
 208 {
 209         const char *title;
 210         ui_rect transform;
 211
 212         int     drag;
 213         ui_px drag_offset[2];
 214 };
 215
 216 static int ui_button( ui_ctx *ctx, u32 id )
 217 {
 218         ui_new_node( ctx );
 219         {
 220                 ui_capture_mouse( ctx, id );
 221
 222                 if( ui_hasmouse(ctx) )
 223                 {
 224                         if( ctx->click_state == 1 )
 225                                 ctx->capture_lock = 1;
 226                         else if( ctx->capture_lock && ctx->click_state == 3 )
 227                         {
 228                                 return 1;
 229                         }
 230                 }
 231         }
 232
 233         return 0;
 234 }
 235
 236 static int ui_window( ui_ctx *ctx, struct ui_window *window, u32 control_group )
 237 {
 238         ctx->id_base = control_group << 16;
 239
 240         if( window->drag )
 241         {
 242                 window->transform[0] = ctx->mouse[0]+window->drag_offset[0];
 243                 window->transform[1] = ctx->mouse[1]+window->drag_offset[1];
 244
 245                 ui_clamp_rect( ctx->stack[0].rect, window->transform );
 246
 247                 if( ctx->click_state == 0 || ctx->click_state == 3 )
 248                 {
 249                         window->drag = 0;
 250                 }
 251         }
 252
 253         ui_rect_copy( window->transform, ctx->cursor );
 254
 255         ui_new_node( ctx );
 256         {
 257                 ui_capture_mouse( ctx, __COUNTER__ );
 258
 259                 // Drag bar
 260                 ctx->cursor[3] = 25;
 261                 ui_new_node( ctx );
 262                 {
 263                         ui_capture_mouse( ctx, __COUNTER__ );
 264
 265                         // title..
 266
 267                         // Close button
 268                         ctx->cursor[2] = 25;
 269                         ui_align_right( ctx );
 270                         ui_rect_pad( ctx, ctx->cursor, 4 );
 271
 272                         if( ui_button( ctx, __COUNTER__ ) )
 273                         {
 274                                 vg_info( "Click clacked\n" );
 275                         }
 276                         ui_end( ctx );
 277
 278                         if( ui_hasmouse( ctx ) )
 279                         {
 280                                 // start drag
 281                                 if( ctx->click_state == 1 )
 282                                 {
 283                                         window->drag = 1;
 284                                         window->drag_offset[0] = window->transform[0]-ctx->mouse[0];
 285                                         window->drag_offset[1] = window->transform[1]-ctx->mouse[1];
 286                                 }
 287                         }
 288                 }
 289                 ui_end( ctx );
 290         }
 291
 292         return 1;
 293 }
 294
 295 static void ui_test(void)
 296 {
 297         /*
 298                 +------------------------------------------------------+
 299                 | Central Market                                    [x]|
 300                 +------+--------------+-+------------------------------+
 301                 | Buy  | Balance      |#| [filters] [favorites]        |
 302                 | <>_  | () 2,356     |#|----------------------------+-+
 303                 |------|--------------|#| [] potion of madness     4 |#|
 304                 | Sell | \ Main sword |#|----------------------------|#|
 305                 | _*^  |--------------|#| [] Balance of time      23 | |
 306                 |------| * Side arm   |#|----------------------------| |
 307                 | 235  |--------------| | [] Strength          5,300 | |
 308                 |      | () Sheild    | |----------------------------| |
 309                 |      |--------------| | [] Bewilder          2,126 | |
 310                 |      [ & Spells     ] |----------------------------| |
 311                 |      |--------------| | [] Eternal flames        6 | |
 312                 +------+--------------+-+----------------------------+-+
 313         */
 314
 315         static ui_ctx ctx = { .padding = 8 };
 316
 317         ui_begin( &ctx, vg_window_x, vg_window_y );
 318
 319         // TODO: Find a more elegent form for this
 320         int mouse_state = 0;
 321         if( vg_get_button( "primary" ) ) mouse_state = 2;
 322         if( vg_get_button_down( "primary" ) ) mouse_state = 1;
 323         if( vg_get_button_up( "primary" ) ) mouse_state = 3;
 324
 325         ui_set_mouse( &ctx, vg_mouse[0], vg_mouse[1], mouse_state );
 326
 327         static struct ui_window window =
 328         {
 329                 .transform = { 20, 20, 500, 350 },
 330                 .title = "Central Market"
 331         };
 332
 333         if( ui_window( &ctx, &window, __COUNTER__ ) )
 334         {
 335                 // Contents
 336         }
 337         ui_end( &ctx );
 338
 339         ui_resolve( &ctx );
 340
 341         m3x3f view = M3X3_IDENTITY;
 342         m3x3_translate( view, (v3f){ -1.0f, 1.0f, 0.0f } );
 343         m3x3_scale( view, (v3f){ 1.0f/((float)vg_window_x*0.5f), -1.0f/((float)vg_window_y*0.5f), 1.0f } );
 344         vg_lines_drawall( (float*)view );
 345 }