src/object/display_effect.cpp

   1 #include <config.h>
   2 #include "display_effect.h"
   3
   4 #include <assert.h>
   5 #include "video/drawing_context.h"
   6 #include "main.h"
   7
   8 DisplayEffect::DisplayEffect()
   9     : type(NO_FADE), fadetime(0), fading(0), black(false)
  10 {
  11 }
  12
  13 DisplayEffect::~DisplayEffect()
  14 {
  15 }
  16
  17 void
  18 DisplayEffect::update(float elapsed_time)
  19 {
  20     switch(type) {
  21         case NO_FADE:
  22             return;
  23         case FADE_IN:
  24             fading -= elapsed_time;
  25             if(fading < 0) {
  26                 type = NO_FADE;
  27             }
  28             break;
  29         case FADE_OUT:
  30             fading -= elapsed_time;
  31             if(fading < 0) {
  32                 type = NO_FADE;
  33                 black = true;
  34             }
  35             break;
  36         default:
  37             assert(false);
  38     }
  39 }
  40
  41 void
  42 DisplayEffect::draw(DrawingContext& context)
  43 {
  44     if(!black && type == NO_FADE)
  45         return;
  46
  47     context.push_transform();
  48     context.set_translation(Vector(0, 0));
  49
  50     uint8_t alpha;
  51     if(black) {
  52         alpha = 255;
  53     } else {
  54         switch(type) {
  55             case FADE_IN:
  56                 alpha = static_cast<uint8_t>
  57                     (fading * 255.0 / fadetime);
  58                 break;
  59             case FADE_OUT:
  60                 alpha = static_cast<uint8_t>
  61                     ((fadetime-fading) * 255.0 / fadetime);
  62                 break;
  63             default:
  64                 alpha = 0;
  65                 assert(false);
  66         }
  67     }
  68     context.draw_filled_rect(Vector(0, 0), Vector(SCREEN_WIDTH, SCREEN_HEIGHT),
  69             Color(0, 0, 0, alpha), LAYER_GUI-10);
  70     context.pop_transform();
  71 }
  72
  73 void
  74 DisplayEffect::fade_out(float fadetime)
  75 {
  76     black = false;
  77     this->fadetime = fadetime;
  78     fading = fadetime;
  79     type = FADE_OUT;
  80 }
  81
  82 void
  83 DisplayEffect::fade_in(float fadetime)
  84 {
  85     black = false;
  86     this->fadetime = fadetime;
  87     fading = fadetime;
  88     type = FADE_IN;
  89 }
  90
  91 void
  92 DisplayEffect::set_black(bool enabled)
  93 {
  94     black = enabled;
  95 }
  96
  97 bool
  98 DisplayEffect::is_black()
  99 {
 100     return black;
 101 }
 102