Mercurial > mbsePi-apps / file comparison
comparison: brewpanel/sdlgui.c
brewpanel/sdlgui.c
- changeset 425
- c51265b518ce
- parent 422
- 13502d0dda65
- child 427
- e8e548922e31
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| 424:d5e36ca9085f | 425:c51265b518ce |
|---|---|
| 493 } | 493 } |
| 494 | 494 |
| 495 | 495 |
| 496 | 496 |
| 497 /* | 497 /* |
| 498 * SDL_Surface 32-bit circle-fill algorithm without using trig | |
| 499 * | |
| 500 * While I humbly call this "Celdecea's Method", odds are that the | |
| 501 * procedure has already been documented somewhere long ago. All of | |
| 502 * the circle-fill examples I came across utilized trig functions or | |
| 503 * scanning neighbor pixels. This algorithm identifies the width of | |
| 504 * a semi-circle at each pixel height and draws a scan-line covering | |
| 505 * that width. | |
| 506 * | |
| 507 * The code is not optimized but very fast, owing to the fact that it | |
| 508 * alters pixels in the provided surface directly rather than through | |
| 509 * function calls. | |
| 510 */ | |
| 511 void SDLGui_fill_circle(SDL_Surface *surface, int cx, int cy, int radius, Uint32 pixel) | |
| 512 { | |
| 513 /* | |
| 514 * Note that there is more to altering the bitrate of this | |
| 515 * method than just changing this value. See how pixels are | |
| 516 * altered at the following web page for tips: | |
| 517 * http://www.libsdl.org/intro.en/usingvideo.html | |
| 518 */ | |
| 519 static const int BPP = 4; | |
| 520 double r = (double)radius; | |
| 521 double dy; | |
| 522 | |
| 523 for (dy = 1; dy <= r; dy += 1.0) { | |
| 524 /* | |
| 525 * This loop is unrolled a bit, only iterating through half of the | |
| 526 * height of the circle. The result is used to draw a scan line and | |
| 527 * its mirror image below it. | |
| 528 * | |
| 529 * The following formula has been simplified from our original. We | |
| 530 * are using half of the width of the circle because we are provided | |
| 531 * with a center and we need left/right coordinates. | |
| 532 */ | |
| 533 double dx = floor(sqrt((2.0 * r * dy) - (dy * dy))); | |
| 534 int x = cx - dx; | |
| 535 | |
| 536 // Grab a pointer to the left-most pixel for each half of the circle | |
| 537 Uint8 *target_pixel_a = (Uint8 *)surface->pixels + ((int)(cy + r - dy)) * surface->pitch + x * BPP; | |
| 538 Uint8 *target_pixel_b = (Uint8 *)surface->pixels + ((int)(cy - r + dy)) * surface->pitch + x * BPP; | |
| 539 | |
| 540 for (; x <= cx + dx; x++) { | |
| 541 *(Uint32 *)target_pixel_a = pixel; | |
| 542 *(Uint32 *)target_pixel_b = pixel; | |
| 543 target_pixel_a += BPP; | |
| 544 target_pixel_b += BPP; | |
| 545 } | |
| 546 } | |
| 547 } | |
| 548 | |
| 549 | |
| 550 | |
| 551 static void SDLGUI_DrawLEDRed(const SGOBJ *bdlg, int objnum) | |
| 552 { | |
| 553 Uint32 color; | |
| 554 | |
| 555 if (bdlg[objnum].state & SG_SELECTED) { | |
| 556 color = SDL_MapRGB(pSdlGuiScrn->format, 255, 64, 0); | |
| 557 } else { | |
| 558 color = SDL_MapRGB(pSdlGuiScrn->format, 128, 16, 0); | |
| 559 } | |
| 560 SDLGui_fill_circle(pSdlGuiScrn, bdlg[objnum].x, bdlg[objnum].y, bdlg[objnum].w, color); | |
| 561 } | |
| 562 | |
| 563 | |
| 564 | |
| 565 static void SDLGUI_DrawLEDBlue(const SGOBJ *bdlg, int objnum) | |
| 566 { | |
| 567 Uint32 color; | |
| 568 | |
| 569 if (bdlg[objnum].state & SG_SELECTED) { | |
| 570 color = SDL_MapRGB(pSdlGuiScrn->format, 64, 160, 255); | |
| 571 } else { | |
| 572 color = SDL_MapRGB(pSdlGuiScrn->format, 16, 48, 112); | |
| 573 } | |
| 574 SDLGui_fill_circle(pSdlGuiScrn, bdlg[objnum].x, bdlg[objnum].y, bdlg[objnum].w, color); | |
| 575 } | |
| 576 | |
| 577 | |
| 578 | |
| 579 static void SDLGUI_DrawLEDGreen(const SGOBJ *bdlg, int objnum) | |
| 580 { | |
| 581 Uint32 color; | |
| 582 | |
| 583 if (bdlg[objnum].state & SG_SELECTED) { | |
| 584 color = SDL_MapRGB(pSdlGuiScrn->format, 80, 240, 0); | |
| 585 } else { | |
| 586 color = SDL_MapRGB(pSdlGuiScrn->format, 32, 112, 0); | |
| 587 } | |
| 588 SDLGui_fill_circle(pSdlGuiScrn, bdlg[objnum].x, bdlg[objnum].y, bdlg[objnum].w, color); | |
| 589 } | |
| 590 | |
| 591 | |
| 592 | |
| 593 static void SDLGUI_DrawLEDYellow(const SGOBJ *bdlg, int objnum) | |
| 594 { | |
| 595 Uint32 color; | |
| 596 | |
| 597 if (bdlg[objnum].state & SG_SELECTED) { | |
| 598 color = SDL_MapRGB(pSdlGuiScrn->format, 255, 255, 0); | |
| 599 } else { | |
| 600 color = SDL_MapRGB(pSdlGuiScrn->format, 160, 144, 0); | |
| 601 } | |
| 602 SDLGui_fill_circle(pSdlGuiScrn, bdlg[objnum].x, bdlg[objnum].y, bdlg[objnum].w, color); | |
| 603 } | |
| 604 | |
| 605 | |
| 606 | |
| 607 /* | |
| 498 * Draw a whole dialog. | 608 * Draw a whole dialog. |
| 499 */ | 609 */ |
| 500 void SDLGui_DrawDialog(const SGOBJ *dlg) | 610 void SDLGui_DrawDialog(const SGOBJ *dlg) |
| 501 { | 611 { |
| 502 int i; | 612 int i; |
| 516 SDLGui_DrawTTF(dlg, i); | 626 SDLGui_DrawTTF(dlg, i); |
| 517 break; | 627 break; |
| 518 case SGBUTTON: | 628 case SGBUTTON: |
| 519 SDLGui_DrawButton(dlg, i); | 629 SDLGui_DrawButton(dlg, i); |
| 520 break; | 630 break; |
| 631 case SGLEDRED: | |
| 632 SDLGUI_DrawLEDRed(dlg, i); | |
| 633 break; | |
| 634 case SGLEDBLUE: | |
| 635 SDLGUI_DrawLEDBlue(dlg, i); | |
| 636 break; | |
| 637 case SGLEDGREEN: | |
| 638 SDLGUI_DrawLEDGreen(dlg, i); | |
| 639 break; | |
| 640 case SGLEDYELLOW: | |
| 641 SDLGUI_DrawLEDYellow(dlg, i); | |
| 642 break; | |
| 521 } | 643 } |
| 522 } | 644 } |
| 523 | 645 |
| 524 SDL_UpdateRect(pSdlGuiScrn, 0,0,0,0); | 646 SDL_UpdateRect(pSdlGuiScrn, 0,0,0,0); |
| 525 } | 647 } |
