src/vg/vg_ui.h

   1 /* Copyright (C) 2021-2022 Harry Godden (hgn) - All Rights Reserved */
   2
   3 #ifndef VG_UI_H
   4 #define VG_UI_H
   5
   6 #include "vg/vg.h"
   7 #include "vg/vg_tex.h"
   8 #include "vg/vg_shader.h"
   9
  10 static struct vg_shader _shader_ui =
  11 {
  12    .name = "[vg] ui",
  13    .link = NULL,
  14    .vs =
  15    {
  16       .orig_file = NULL,
  17       .static_src =
  18         "layout (location=0) in vec2 a_co;"
  19         "layout (location=1) in vec2 a_uv;"
  20         "layout (location=2) in vec4 a_colour;"
  21         "layout (location=3) in vec4 a_clip;"
  22         "uniform mat3 uPv;"
  23         ""
  24         "out vec2 aTexCoords;"
  25         "out vec4 aColour;"
  26         "out vec2 aWsp;"
  27         "out vec4 aClip;"
  28         ""
  29         "void main()"
  30         "{"
  31                 "gl_Position = vec4( uPv * vec3( a_co, 1.0 ), 1.0 );"
  32                 "aTexCoords = a_uv * 0.0078125;"
  33                 "aColour = a_colour;"
  34
  35                 "aWsp = a_co;"
  36                 "aClip = a_clip;"
  37         "}",
  38    },
  39    .fs =
  40    {
  41       .orig_file = NULL,
  42       .static_src =
  43         "uniform sampler2D uTexGlyphs;"
  44         "out vec4 FragColor;"
  45         ""
  46         "in vec2 aTexCoords;"
  47         "in vec4 aColour;"
  48         ""
  49         "in vec2 aWsp;"
  50         "in vec4 aClip;"
  51         ""
  52         "void main()"
  53         "{"
  54                 "float clip_blend = step( aWsp.x, aClip.z ) *"
  55                          "step( aWsp.y, aClip.w ) *"
  56                          "step( aClip.x, aWsp.x ) *"
  57                          "step( aClip.y, aWsp.y ); "
  58
  59                 "vec4 glyph = vec4(1.0,1.0,1.0,1.0);"
  60
  61                 "if( aColour.a == 0.0 )"
  62                 "{"
  63                         "glyph = texture( uTexGlyphs, aTexCoords );"
  64                         "glyph.a = smoothstep( 0.47, 0.53, glyph.r );"
  65                 "}"
  66                 "else"
  67                 "{"
  68                         "glyph.a = aColour.a;"
  69                 "}"
  70
  71                 "FragColor = vec4( aColour.rgb, glyph.a*clip_blend );"
  72         "}"
  73    }
  74 };
  75
  76 typedef i16                             ui_px;
  77 typedef u32                             ui_colour;
  78 typedef ui_px                           ui_rect[4];
  79 typedef struct ui_ctx   ui_ctx;
  80 typedef struct ui_colourset ui_colourset;
  81
  82 /* Relative to cursor p0 */
  83 enum ui_text_align
  84 {
  85    k_text_align_left = 0,
  86    k_text_align_right = 1,
  87    k_text_align_center = 2
  88 };
  89
  90 struct ui_colourset
  91 {
  92         union
  93         {
  94                 struct
  95                 {
  96                         ui_colour main;
  97                         ui_colour hover;
  98                         ui_colour active;
  99                 };
 100                 struct
 101                 {
 102                         ui_colour background;
 103                         ui_colour bar;
 104                         ui_colour bar_hover;
 105                 };
 106         };
 107 };
 108
 109 struct ui_ctx
 110 {
 111         struct ui_qnode
 112         {
 113                 ui_rect                 rect;
 114                 ui_colour       colour;
 115                 int                     mouse_over;
 116                 int                     capture_id;
 117         }
 118         stack[ 32 ];
 119
 120         #pragma pack(push,1)
 121         struct ui_vert
 122         {
 123                 ui_px co[2];
 124                 u8 uv[2];
 125                 u32 colour;
 126                 ui_rect clip;
 127         }
 128         *verts;
 129         #pragma pack(pop)
 130
 131    u32 control_id;
 132
 133         u32 num_verts;
 134         u16 *indices;
 135         u32 num_indices;
 136
 137         ui_rect clipping;
 138         ui_rect cursor;
 139         u32 stack_count;
 140         u32 capture_mouse_id;
 141         int capture_lock;
 142
 143
 144         /* User input */
 145         ui_px mouse[2];
 146         int click_state;        /* 0: released, 1: on down, 2: pressed, 3: on release */
 147
 148         ui_colourset *colours;
 149
 150         GLuint vao;
 151         GLuint vbo;
 152         GLuint ebo;
 153
 154         struct ui_image
 155         {
 156                 ui_rect rc;
 157                 GLuint image;
 158         }
 159         images[16];
 160         int image_count;
 161 };
 162
 163 #define UI_GLYPH_SPACING_X 9
 164
 165 static GLuint ui_glyph_texture = 0;
 166 static ui_colourset ui_default_colours = {
 167         .main = 0xff807373,
 168         .hover = 0xff918484,
 169         .active = 0xffad9f9e
 170 };
 171
 172 static ui_ctx ui_global_ctx;
 173
 174 static void ui_init_context( ui_ctx *ctx, int index_buffer_size )
 175 {
 176         u32 vertex_buffer_size = (index_buffer_size+(index_buffer_size/2));
 177
 178         /* Generate the buffer we are gonna be drawing to */
 179         {
 180                 glGenVertexArrays(1, &ctx->vao);
 181                 glGenBuffers( 1, &ctx->vbo );
 182                 glGenBuffers( 1, &ctx->ebo );
 183                 glBindVertexArray( ctx->vao );
 184
 185                 glBindBuffer( GL_ARRAY_BUFFER, ctx->vbo );
 186
 187                 glBufferData( GL_ARRAY_BUFFER,
 188             vertex_buffer_size * sizeof( struct ui_vert ),
 189             NULL, GL_DYNAMIC_DRAW );
 190                 glBindVertexArray( ctx->vao );
 191
 192                 glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ctx->ebo );
 193                 glBufferData( GL_ELEMENT_ARRAY_BUFFER,
 194             index_buffer_size * sizeof( u16 ), NULL, GL_DYNAMIC_DRAW );
 195
 196                 u32 const stride = sizeof( struct ui_vert );
 197
 198                 /* XY */
 199                 glVertexAttribPointer( 0, 2, GL_SHORT, GL_FALSE,
 200             stride, (void *)offsetof( struct ui_vert, co ) );
 201                 glEnableVertexAttribArray( 0 );
 202
 203                 /* UV */
 204                 glVertexAttribPointer( 1, 2, GL_UNSIGNED_BYTE, GL_FALSE,
 205             stride, (void *)offsetof( struct ui_vert, uv ) );
 206                 glEnableVertexAttribArray( 1 );
 207
 208                 /* COLOUR */
 209                 glVertexAttribPointer( 2, 4, GL_UNSIGNED_BYTE, GL_TRUE, stride,
 210             (void *)offsetof( struct ui_vert, colour ) );
 211                 glEnableVertexAttribArray( 2 );
 212
 213                 /* CLIPPING */
 214                 glVertexAttribPointer( 3, 4, GL_SHORT, GL_FALSE, stride,
 215             (void *)offsetof( struct ui_vert, clip ) );
 216                 glEnableVertexAttribArray( 3 );
 217         }
 218
 219         /* Initialize default context */
 220         {
 221                 ctx->verts = (struct ui_vert *)malloc(
 222             vertex_buffer_size * sizeof(struct ui_vert) );
 223                 ctx->indices = (u16*)malloc( index_buffer_size * sizeof(u16) );
 224
 225       if( !ctx->colours )
 226          ctx->colours = &ui_default_colours;
 227         }
 228 }
 229
 230 static void ui_context_free( ui_ctx *ctx )
 231 {
 232         glDeleteVertexArrays( 1, &ctx->vao );
 233         glDeleteBuffers( 1, &ctx->vbo );
 234         glDeleteBuffers( 1, &ctx->ebo );
 235
 236         free( ctx->verts );
 237         free( ctx->indices );
 238 }
 239
 240 static void ui_default_init(void)
 241 {
 242         /* Load default font */
 243    u32 compressed[] = {
 244       #include "vg/vg_pxfont.h"
 245    };
 246
 247    u32 pixels = 0, total = 256*256, data = 0;
 248    u8 *image = malloc( total );
 249
 250    while( pixels < total )
 251    {
 252       for( int b = 31; b >= 0; b-- )
 253       {
 254          image[ pixels ++ ] = (compressed[data] & (0x1 << b))? 0xff: 0x00;
 255
 256          if( pixels >= total )
 257          {
 258             total = 0;
 259             break;
 260          }
 261       }
 262       data++;
 263    }
 264
 265    glGenTextures( 1, &ui_glyph_texture );
 266    glBindTexture( GL_TEXTURE_2D, ui_glyph_texture );
 267
 268    glTexImage2D( GL_TEXTURE_2D, 0, GL_R8, 256, 256, 0,
 269          GL_RED, GL_UNSIGNED_BYTE, image );
 270
 271    vg_tex2d_clamp();
 272    vg_tex2d_nearest();
 273
 274    free( image );
 275
 276    vg_shader_register( &_shader_ui );
 277         ui_init_context( &ui_global_ctx, 20000 );
 278 }
 279
 280 static void ui_default_free(void)
 281 {
 282    glDeleteTextures( 1, &ui_glyph_texture );
 283         ui_context_free( &ui_global_ctx );
 284 }
 285
 286 static struct ui_vert *ui_fill_rect_uv( ui_ctx *ctx, ui_rect rect,
 287       u32 colour, ui_px uv[4] );
 288
 289 static void ui_draw( ui_ctx *ctx, m3x3f view_override )
 290 {
 291         u32 num_indices_normal = ctx->num_indices;
 292
 293         /* Append images to back of buffer */
 294         for( int i = 0; i < ctx->image_count; i ++ )
 295    {
 296                 ui_fill_rect_uv( ctx, ctx->images[i].rc,
 297             0xffffffff, (ui_px[4]){0,0,128,128} );
 298    }
 299
 300         glBindVertexArray( ctx->vao );
 301
 302         glBindBuffer( GL_ARRAY_BUFFER, ctx->vbo );
 303         glBufferSubData( GL_ARRAY_BUFFER, 0,
 304          ctx->num_verts * sizeof( struct ui_vert ), ctx->verts );
 305
 306         glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, ctx->ebo );
 307         glBufferSubData( GL_ELEMENT_ARRAY_BUFFER, 0,
 308          ctx->num_indices * sizeof( u16 ), ctx->indices );
 309
 310         glEnable(GL_BLEND);
 311         glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 312         glBlendEquation(GL_FUNC_ADD);
 313
 314    glUseProgram( _shader_ui.id );
 315
 316         m3x3f view = M3X3_IDENTITY;
 317
 318         if( !view_override )
 319         {
 320                 view_override = view;
 321
 322                 m3x3_translate( view, (v3f){ -1.0f, 1.0f, 0.0f } );
 323                 m3x3_scale( view, (v3f){ 1.0f/((float)vg_window_x*0.5f),
 324                               -1.0f/((float)vg_window_y*0.5f), 1.0f } );
 325         }
 326
 327    /* TODO? */
 328         glUniformMatrix3fv( glGetUniformLocation( _shader_ui.id, "uPv" ), 1,
 329          GL_FALSE, (float *)view_override );
 330
 331         glActiveTexture( GL_TEXTURE0 );
 332         glBindTexture( GL_TEXTURE_2D, ui_glyph_texture );
 333         glUniform1i( glGetUniformLocation( _shader_ui.id, "uTexGlyphs" ), 0 );
 334
 335         glDrawElements( GL_TRIANGLES, num_indices_normal,
 336          GL_UNSIGNED_SHORT, (void*)(0) );
 337
 338         /* Draw image elements */
 339         for( int i = 0; i < ctx->image_count; i ++ )
 340         {
 341                 struct ui_image *img = &ctx->images[i];
 342
 343                 glBindTexture( GL_TEXTURE_2D, img->image );
 344                 glDrawElements( GL_TRIANGLES, 6, GL_UNSIGNED_SHORT,
 345             (void*)( (num_indices_normal + 6*i)*sizeof(u16) ) );
 346         }
 347
 348         glDisable(GL_BLEND);
 349 }
 350
 351 /*
 352  * Rect controls
 353  */
 354 static void ui_rect_copy( ui_rect src, ui_rect dst )
 355 {
 356         dst[0] = src[0];
 357         dst[1] = src[1];
 358         dst[2] = src[2];
 359         dst[3] = src[3];
 360 }
 361
 362 static void ui_rect_pad( ui_rect rect, ui_px pad )
 363 {
 364         rect[0] += pad;
 365         rect[1] += pad;
 366         rect[2] -= pad*2;
 367         rect[3] -= pad*2;
 368 }
 369
 370 /*
 371  * Stack control
 372  */
 373 static struct ui_qnode *ui_current( ui_ctx *ctx )
 374 {
 375         return &ctx->stack[ ctx->stack_count-1 ];
 376 }
 377
 378 static void ui_new_node( ui_ctx *ctx )
 379 {
 380         if( ctx->stack_count == vg_list_size( ctx->stack ) )
 381                 vg_exiterr( "[UI] Stack overflow while creating box!" );
 382
 383         struct ui_qnode *parent = &ctx->stack[ ctx->stack_count-1 ];
 384         struct ui_qnode *node = &ctx->stack[ ctx->stack_count++ ];
 385         ui_rect_copy( ctx->cursor, node->rect );
 386
 387         if( parent->mouse_over )
 388         {
 389                 if( ctx->mouse[0] >= node->rect[0] &&
 390           ctx->mouse[0] < node->rect[0]+node->rect[2] &&
 391                          ctx->mouse[1] >= node->rect[1] &&
 392           ctx->mouse[1] < node->rect[1]+node->rect[3] )
 393                         node->mouse_over = 1;
 394                 else
 395                         node->mouse_over = 0;
 396         }
 397         else
 398         {
 399                 node->mouse_over = 0;
 400         }
 401 }
 402
 403 static int ui_hasmouse( ui_ctx *ctx )
 404 {
 405         struct ui_qnode *node = ui_current( ctx );
 406         return (node->mouse_over && (node->capture_id == ctx->capture_mouse_id));
 407 }
 408
 409 static void ui_end( ui_ctx *ctx )
 410 {
 411         struct ui_qnode *node = &ctx->stack[ --ctx->stack_count ];
 412         ui_rect_copy( node->rect, ctx->cursor );
 413 }
 414
 415 static void ui_end_down( ui_ctx *ctx )
 416 {
 417         ui_px height = ui_current( ctx )->rect[3];
 418         ui_end( ctx );
 419         ctx->cursor[1] += height;
 420 }
 421
 422 static void ui_end_right( ui_ctx *ctx )
 423 {
 424         ui_px width = ui_current( ctx )->rect[2];
 425         ui_end( ctx );
 426         ctx->cursor[0] += width;
 427 }
 428
 429 static void ui_fill_y( ui_ctx *ctx )
 430 {
 431         struct ui_qnode *node = ui_current( ctx );
 432         ctx->cursor[3] = node->rect[3] - (ctx->cursor[1]-node->rect[1]);
 433 }
 434
 435 static void ui_fill_x( ui_ctx *ctx )
 436 {
 437         struct ui_qnode *node = ui_current( ctx );
 438         ctx->cursor[2] = node->rect[2] - (ctx->cursor[0]-node->rect[0]);
 439 }
 440
 441 static void ui_align_bottom( ui_ctx *ctx )
 442 {
 443         struct ui_qnode *node = ui_current( ctx );
 444         ctx->cursor[1] = node->rect[1] + node->rect[3] - ctx->cursor[3];
 445 }
 446
 447 static void ui_align_right( ui_ctx *ctx )
 448 {
 449         struct ui_qnode *node = ui_current( ctx );
 450         ctx->cursor[0] = node->rect[0] + node->rect[2] - ctx->cursor[2];
 451 }
 452
 453 static void ui_align_top( ui_ctx *ctx )
 454 {
 455         ctx->cursor[1] = ui_current( ctx )->rect[1];
 456 }
 457
 458 static void ui_align_left( ui_ctx *ctx )
 459 {
 460         ctx->cursor[0] = ui_current( ctx )->rect[0];
 461 }
 462
 463 static void ui_clamp_rect( ui_rect parent, ui_rect dest )
 464 {
 465         dest[0] = vg_min( parent[0] + parent[2] - dest[2], dest[0] );
 466         dest[1] = vg_min( parent[1] + parent[3] - dest[3], dest[1] );
 467         dest[0] = vg_max( parent[0], dest[0] );
 468         dest[1] = vg_max( parent[1], dest[1] );
 469 }
 470
 471 static void ui_capture_mouse( ui_ctx *ctx, u32 id )
 472 {
 473         struct ui_qnode *node = &ctx->stack[ ctx->stack_count-1 ];
 474         node->capture_id = id;
 475
 476         if( !ctx->capture_lock && node->mouse_over )
 477         {
 478                 ctx->capture_mouse_id = id;
 479         }
 480 }
 481
 482 static int ui_want_mouse( ui_ctx *ctx )
 483 {
 484         return ctx->capture_mouse_id == 0? 0: 1;
 485 }
 486
 487 static void ui_set_clip( ui_ctx *ctx, ui_rect clip )
 488 {
 489         ctx->clipping[0] = clip[0];
 490         ctx->clipping[1] = clip[1];
 491         ctx->clipping[2] = clip[0] + clip[2];
 492         ctx->clipping[3] = clip[1] + clip[3];
 493 }
 494
 495 static void ui_release_clip( ui_ctx *ctx )
 496 {
 497         ctx->clipping[0] = -32000;
 498         ctx->clipping[1] = -32000;
 499         ctx->clipping[2] =  32000;
 500         ctx->clipping[3] =  32000;
 501 }
 502
 503 static struct ui_vert *ui_fill_rect_uv( ui_ctx *ctx, ui_rect rect,
 504       u32 colour, ui_px uv[4] )
 505 {
 506         struct ui_vert *vertices = &ctx->verts[ ctx->num_verts ];
 507         vertices[0].co[0] = rect[0];
 508         vertices[0].co[1] = rect[1];
 509         vertices[0].uv[0] = uv[0];
 510         vertices[0].uv[1] = uv[1];
 511         vertices[0].colour = colour;
 512         vertices[1].co[0] = rect[0]+rect[2];
 513         vertices[1].co[1] = rect[1];
 514         vertices[1].uv[0] = uv[2];
 515         vertices[1].uv[1] = uv[1];
 516         vertices[1].colour = colour;
 517         vertices[2].co[0] = rect[0]+rect[2];
 518         vertices[2].co[1] = rect[1]+rect[3];
 519         vertices[2].uv[0] = uv[2];
 520         vertices[2].uv[1] = uv[3];
 521         vertices[2].colour = colour;
 522         vertices[3].co[0] = rect[0];
 523         vertices[3].co[1] = rect[1]+rect[3];
 524         vertices[3].uv[0] = uv[0];
 525         vertices[3].uv[1] = uv[3];
 526         vertices[3].colour = colour;
 527         u16 ind_start = ctx->num_verts;
 528         u16 *indices = &ctx->indices[ ctx->num_indices ];
 529
 530         ui_rect_copy( ctx->clipping, vertices[0].clip );
 531         ui_rect_copy( ctx->clipping, vertices[1].clip );
 532         ui_rect_copy( ctx->clipping, vertices[2].clip );
 533         ui_rect_copy( ctx->clipping, vertices[3].clip );
 534
 535         indices[0] = ind_start+0;
 536         indices[1] = ind_start+2;
 537         indices[2] = ind_start+1;
 538
 539         indices[3] = ind_start+0;
 540         indices[4] = ind_start+3;
 541         indices[5] = ind_start+2;
 542
 543         ctx->num_indices += 6;
 544         ctx->num_verts += 4;
 545
 546         return vertices;
 547 }
 548
 549 static struct ui_vert *ui_fill_rect( ui_ctx *ctx, ui_rect rect, u32 colour )
 550 {
 551         return ui_fill_rect_uv( ctx, rect, colour, (ui_px[4]){ 4,4, 4,4 } );
 552 }
 553
 554 static ui_px ui_text_line_offset( const char *str, ui_px scale,
 555       enum ui_text_align align )
 556 {
 557    if( align == k_text_align_left )
 558       return 0;
 559
 560    int length = 0;
 561    const char *_c = str;
 562    char c;
 563
 564    while( (c = *(_c ++)) )
 565       if( c >= 32 && c <= 126 )
 566          length ++;
 567       else if( c == '\n' )
 568          break;
 569
 570    if( align == k_text_align_right )
 571       return -length * scale*8;
 572    else
 573       return (-length * scale*8) / 2;
 574 }
 575
 576 static void ui_text( ui_ctx *ctx, ui_px pos[2],
 577       const char *str, ui_px scale, enum ui_text_align align )
 578 {
 579         ui_rect text_cursor;
 580         u32 current_colour = 0x00ffffff;
 581
 582    const char *_c = str;
 583         u8 c;
 584
 585         text_cursor[0] = pos[0] + ui_text_line_offset( str, scale, align );
 586         text_cursor[1] = pos[1];
 587         text_cursor[2] = 8*scale;
 588         text_cursor[3] = 14*scale;
 589
 590         while( (c = *(_c ++)) )
 591         {
 592                 if( c == '\n' )
 593                 {
 594                         text_cursor[1] += 14*scale;
 595                         text_cursor[0] = pos[0] + ui_text_line_offset( _c, scale, align );
 596                         continue;
 597                 }
 598                 else if( c >= 33 )
 599                 {
 600                         u8 glyph_base[2];
 601                         u8 glyph_index = c;
 602                         glyph_base[0] = glyph_index & 0xf;
 603                         glyph_base[1] = (glyph_index-glyph_base[0])>>4;
 604
 605                         glyph_base[0] *= 8;
 606                         glyph_base[1] *= 8;
 607
 608                         ui_fill_rect_uv( ctx, text_cursor, current_colour, (ui_px[4])
 609             {
 610                glyph_base[0]+2,
 611                glyph_base[1]+1,
 612                glyph_base[0]+6,
 613                glyph_base[1]+8
 614             });
 615                 }
 616                 else if( c == '\x1B' )
 617                 {
 618                         _c ++;
 619                         u16 colour_id = 0;
 620                         for( int i = 0; i < 3; i ++ )
 621                         {
 622                                 if( _c[i] )
 623                                 {
 624                                         if( _c[i] == 'm' )
 625                                         {
 626                                                 _c = _c + i + 1;
 627
 628                                                 switch( colour_id )
 629                                                 {
 630                                                         case '0': current_colour = 0x00ffffff; break;
 631                                                         case '3'|'1'<<8: current_colour = 0x00201fee; break;
 632                                                         case '3'|'2'<<8: current_colour = 0x0037e420; break;
 633                                                         case '3'|'3'<<8: current_colour = 0x000ed8e2; break;
 634                                                         case '3'|'4'<<8: current_colour = 0x00f15010; break;
 635                                                         case '3'|'5'<<8: current_colour = 0x00ee20ee; break;
 636                                                         case '3'|'6'<<8: current_colour = 0x00eeee20; break;
 637                                                         case '3'|'7'<<8: current_colour = 0x00ffffff; break;
 638                                                 }
 639
 640                                                 break;
 641                                         }
 642
 643                                         colour_id |= _c[i] << (i*8);
 644                                 }
 645                                 else
 646                                 {
 647                                         _c = _c +i;
 648                                         break;
 649                                 }
 650                         }
 651
 652          continue;
 653                 }
 654       else if( c == '\t' )
 655       {
 656          text_cursor[0] += UI_GLYPH_SPACING_X*scale*4;
 657          continue;
 658       }
 659
 660         text_cursor[0] += UI_GLYPH_SPACING_X*scale;
 661         }
 662 }
 663
 664 /*
 665  * API Control
 666  */
 667 static void ui_begin( ui_ctx *ctx, ui_px res_x, ui_px res_y )
 668 {
 669         ctx->cursor[0] = 0;
 670         ctx->cursor[1] = 0;
 671         ctx->cursor[2] = res_x;
 672         ctx->cursor[3] = res_y;
 673
 674         ui_rect_copy( ctx->cursor, ctx->stack[0].rect );
 675         ctx->stack[0].mouse_over = 1;
 676
 677         ctx->stack_count = 1;
 678
 679         ctx->num_verts = 0;
 680         ctx->num_indices = 0;
 681
 682         ui_release_clip( ctx );
 683
 684         if( ctx->click_state == 0 )
 685                 ctx->capture_mouse_id = 0;
 686
 687         ctx->image_count = 0;
 688 }
 689
 690 static void ui_resolve( ui_ctx *ctx )
 691 {
 692         if( ctx->stack_count-1 )
 693                 vg_exiterr( "[UI] Mismatched node create/drestroy!" );
 694
 695         if( ctx->click_state == 3 || ctx->click_state == 0 )
 696         {
 697                 ctx->capture_lock = 0;
 698         }
 699 }
 700
 701 static void ui_set_mouse( ui_ctx *ctx, int x, int y, int click_state )
 702 {
 703         ctx->mouse[0] = x;
 704         ctx->mouse[1] = y;
 705
 706         ctx->click_state = click_state;
 707 }
 708
 709 /*
 710  * High level controls
 711  */
 712 struct ui_window
 713 {
 714         const char *title;
 715         ui_rect transform;
 716
 717         int     drag;
 718         ui_px drag_offset[2];
 719 };
 720
 721 enum button_state
 722 {
 723         k_button_released = 0,
 724         k_button_start_click,
 725         k_button_click,
 726         k_button_hold
 727 };
 728
 729 static int ui_button( ui_ctx *ctx )
 730 {
 731    u32 uid = ctx->control_id ++;
 732
 733         ui_new_node( ctx );
 734         {
 735                 ui_capture_mouse( ctx, uid );
 736
 737                 if( ui_hasmouse(ctx) )
 738                 {
 739                         ui_fill_rect( ctx, ctx->cursor, ctx->colours->hover );
 740
 741                         if( ctx->click_state == 1 )
 742                         {
 743                                 ctx->capture_lock = 1;
 744                                 return k_button_start_click;
 745                         }
 746                         else if( ctx->capture_lock && ctx->click_state == 3 )
 747                                 return k_button_click;
 748                         else if( ctx->capture_lock && ctx->click_state == 2 )
 749                                 return k_button_hold;
 750
 751          return k_button_click;
 752                 }
 753                 else
 754                         ui_fill_rect( ctx, ctx->cursor, ctx->colours->main );
 755         }
 756
 757         return k_button_released;
 758 }
 759
 760 static int ui_window( ui_ctx *ctx, struct ui_window *window, u32 control_group )
 761 {
 762         if( window->drag )
 763         {
 764                 window->transform[0] = ctx->mouse[0]+window->drag_offset[0];
 765                 window->transform[1] = ctx->mouse[1]+window->drag_offset[1];
 766
 767                 ui_clamp_rect( ctx->stack[0].rect, window->transform );
 768
 769                 if( ctx->click_state == 0 || ctx->click_state == 3 )
 770                 {
 771                         window->drag = 0;
 772                 }
 773         }
 774
 775         ui_rect_copy( window->transform, ctx->cursor );
 776
 777         ui_new_node( ctx );
 778         {
 779                 ui_capture_mouse( ctx, ctx->control_id ++ );
 780
 781                 /* Drag bar */
 782                 ctx->cursor[3] = 25;
 783                 ui_new_node( ctx );
 784                 {
 785                         ui_capture_mouse( ctx, ctx->control_id ++ );
 786
 787                         struct ui_vert *drag_bar = ui_fill_rect( ctx, ctx->cursor, 0xff555555 );
 788
 789                         /* title.. */
 790                         ctx->cursor[0] += 2;
 791                         ctx->cursor[1] += 2;
 792                         ui_text( ctx, ctx->cursor, window->title, 2, 0 );
 793
 794                         /* Close button */
 795                         ctx->cursor[3] = 25;
 796                         ctx->cursor[2] = 25;
 797                         ui_align_right( ctx );
 798                         ui_align_top( ctx );
 799                         ui_rect_pad( ctx->cursor, 4 );
 800
 801                         if( ui_button( ctx ) )
 802                         {
 803                                 vg_info( "Click clacked\n" );
 804                         }
 805                         ctx->cursor[0] += 2;
 806                         ui_text( ctx, ctx->cursor, "x", 2, 0 );
 807                         ui_end( ctx );
 808
 809                         if( ui_hasmouse( ctx ) )
 810                         {
 811                                 drag_bar[0].colour = 0xff777777;
 812                                 drag_bar[1].colour = 0xff777777;
 813                                 drag_bar[2].colour = 0xff777777;
 814                                 drag_bar[3].colour = 0xff777777;
 815
 816                                 /* start drag */
 817                                 if( ctx->click_state == 1 )
 818                                 {
 819                                         window->drag = 1;
 820                                         window->drag_offset[0] = window->transform[0]-ctx->mouse[0];
 821                                         window->drag_offset[1] = window->transform[1]-ctx->mouse[1];
 822                                 }
 823                         }
 824                 }
 825                 ui_end_down( ctx );
 826         }
 827
 828         return 1;
 829 }
 830
 831 static void ui_push_image( ui_ctx *ctx, ui_rect rc, GLuint image )
 832 {
 833         struct ui_image *img = &ctx->images[ ctx->image_count ++ ];
 834         ui_rect_copy( rc, img->rc );
 835         img->image = image;
 836 }
 837
 838 struct ui_slider
 839 {
 840    float *data;
 841    float min, max;
 842 };
 843
 844 struct ui_slider_vector
 845 {
 846    float *data, min, max;
 847    struct ui_slider sub[4];
 848    u32 len;
 849 };
 850
 851 struct ui_checkbox
 852 {
 853    int *data;
 854 };
 855
 856 static void ui_slider( ui_ctx *ctx, struct ui_slider *slider )
 857 {
 858    ui_new_node( ctx );
 859
 860    ui_px slider_start = ctx->cursor[0];
 861
 862    float const ftotal = ctx->cursor[2],
 863                fwidth = ftotal*0.25f,
 864                fmove  = ftotal - fwidth,
 865                fstart = fwidth*0.5f,
 866                frange = slider->max-slider->min,
 867                fpos   = (*slider->data - slider->min) / frange;
 868
 869    ui_fill_rect( ctx, ctx->cursor, 0xff111111 );
 870    ctx->cursor[2] = fwidth;
 871    ctx->cursor[0] = slider_start + fpos * fmove;
 872
 873    u32 uid = ctx->control_id ++;
 874    int status = ui_button( ctx );
 875    if( ctx->capture_lock && (ctx->capture_mouse_id == uid))
 876    {
 877       float ui_new = ctx->mouse[0],
 878             local  = ui_new - (slider_start + fstart),
 879             zo     = vg_clampf(local / fmove,0.0f,1.0f);
 880
 881       *slider->data = vg_lerpf( slider->min, slider->max, zo );
 882    }
 883
 884    ctx->cursor[0] += 4;
 885    ctx->cursor[1] += 4;
 886
 887    char buf[12];
 888    snprintf( buf, 12, "%.2f", *slider->data );
 889    ui_text( ctx, ctx->cursor, buf, 1, 0 );
 890    ui_end_down( ctx );
 891    ui_end_down( ctx );
 892 }
 893
 894 static void ui_slider_vector( ui_ctx *ctx, struct ui_slider_vector *slider )
 895 {
 896    for( int i=0; i<slider->len; i++ )
 897    {
 898       slider->sub[i].data = &slider->data[i];
 899       slider->sub[i].min = slider->min;
 900       slider->sub[i].max = slider->max;
 901       ui_slider( ctx, &slider->sub[i] );
 902    }
 903 }
 904
 905 static void ui_checkbox( ui_ctx *ctx, struct ui_checkbox *cb )
 906 {
 907    if( ui_button(ctx) == k_button_click )
 908       *cb->data ^= 0x1;
 909
 910    ui_new_node(ctx);
 911    ui_rect_pad( ctx->cursor, 4 );
 912    if( *cb->data )
 913       ui_fill_rect( ctx, ctx->cursor, 0xff00e052 );
 914    else
 915       ui_fill_rect( ctx, ctx->cursor, 0xff0052e0 );
 916
 917    ui_end(ctx);
 918    ui_end_down(ctx);
 919 }
 920
 921 /* Shortnames */
 922 #define gui_draw(...) ui_draw( &ui_global_ctx, __VA_ARGS__)
 923 #define gui_current(...) ui_current( &ui_global_ctx, __VA_ARGS__)
 924 #define gui_new_node() ui_new_node( &ui_global_ctx )
 925 #define gui_hasmouse(...) ui_hasmouse( &ui_global_ctx, __VA_ARGS__)
 926 #define gui_end() ui_end( &ui_global_ctx )
 927 #define gui_end_down() ui_end_down( &ui_global_ctx )
 928 #define gui_end_right() ui_end_right( &ui_global_ctx )
 929 #define gui_fill_y() ui_fill_y( &ui_global_ctx)
 930 #define gui_fill_x() ui_fill_x( &ui_global_ctx)
 931 #define gui_align_bottom() ui_align_bottom( &ui_global_ctx )
 932 #define gui_align_right() ui_align_right( &ui_global_ctx )
 933 #define gui_align_top() ui_align_top( &ui_global_ctx )
 934 #define gui_align_left() ui_align_left( &ui_global_ctx )
 935 #define gui_clamp_rect(...) ui_clamp_rect( &ui_global_ctx, __VA_ARGS__)
 936 #define gui_capture_mouse(...) ui_capture_mouse( &ui_global_ctx, __VA_ARGS__)
 937 #define gui_set_clip(...) ui_set_clip( &ui_global_ctx, __VA_ARGS__)
 938 #define gui_release_clip() ui_release_clip( &ui_global_ctx )
 939 #define gui_fill_rect_uv(...) ui_fill_rect_uv( &ui_global_ctx, __VA_ARGS__)
 940 #define gui_fill_rect(...) ui_fill_rect( &ui_global_ctx, __VA_ARGS__)
 941 #define gui_text(...) ui_text( &ui_global_ctx, __VA_ARGS__)
 942 #define gui_begin(...) ui_begin( &ui_global_ctx, __VA_ARGS__)
 943 #define gui_resolve(...) ui_resolve( &ui_global_ctx, __VA_ARGS__)
 944 #define gui_set_mouse(...) ui_set_mouse( &ui_global_ctx, __VA_ARGS__)
 945 #define gui_button(...) ui_button( &ui_global_ctx, __VA_ARGS__)
 946 #define gui_window(...) ui_window( &ui_global_ctx, __VA_ARGS__)
 947 #define gui_want_mouse() ui_want_mouse( &ui_global_ctx )
 948 #define gui_push_image(...) ui_push_image( &ui_global_ctx, __VA_ARGS__ )
 949 #define gui_reset_colours(...) ui_reset_colours( &ui_global_ctx )
 950
 951 #endif /* VG_UI_H */