src/game/level/background.c

   1 #include "system/stacktrace.h"
   2
   3 #include "game/level/background.h"
   4 #include "math/rand.h"
   5 #include "math/rect.h"
   6 #include "system/line_stream.h"
   7 #include "system/lt.h"
   8 #include "system/nth_alloc.h"
   9 #include "system/log.h"
  10
  11 #define BACKGROUND_CHUNK_COUNT 5
  12 #define BACKGROUND_CHUNK_WIDTH 250.0f
  13 #define BACKGROUND_CHUNK_HEIGHT 250.0f
  14
  15 static void chunk_of_point(Point p, int *x, int *y);
  16 int render_chunk(const Background *background,
  17                  Camera *camera,
  18                  int x, int y,
  19                  Color color,
  20                  Vec position,
  21                  float parallax);
  22
  23 struct Background
  24 {
  25     Lt lt;
  26     Color base_color;
  27     Vec position;
  28     int debug_mode;
  29 };
  30
  31 Background *create_background(Color base_color)
  32 {
  33     Lt lt = {0};
  34     if (lt == NULL) {
  35         return NULL;
  36     }
  37
  38     Background *background = PUSH_LT(lt, nth_calloc(1, sizeof(Background)), free);
  39     if (background == NULL) {
  40         RETURN_LT(lt, NULL);
  41     }
  42
  43     background->base_color = base_color;
  44     background->position = vec(0.0f, 0.0f);
  45     background->debug_mode = 0;
  46     background->lt = lt;
  47
  48     return background;
  49 }
  50
  51 Background *create_background_from_line_stream(LineStream *line_stream)
  52 {
  53     char color[7];
  54     if (sscanf(line_stream_next(line_stream), "%6s", color) == EOF) {
  55         log_fail("Could not read background's color\n");
  56         return NULL;
  57     }
  58
  59     return create_background(hexstr(color));
  60 }
  61
  62 void destroy_background(Background *background)
  63 {
  64     trace_assert(background);
  65     RETURN_LT0(background->lt);
  66 }
  67
  68 /* TODO(#182): background chunks are randomly disappearing when the size of the window is less than size of the chunk  */
  69 int background_render(const Background *background,
  70                       Camera *camera)
  71 {
  72     trace_assert(background);
  73     trace_assert(camera);
  74
  75     if (camera_clear_background(
  76             camera,
  77             background->base_color) < 0) {
  78         return -1;
  79     }
  80
  81     const Rect view_port = camera_view_port(camera);
  82     const Vec position = vec(view_port.x, view_port.y);
  83
  84     for (int l = 0; l < 3; ++l) {
  85         const float parallax = 1.0f - 0.2f * (float)l;
  86
  87         int min_x = 0, min_y = 0;
  88         chunk_of_point(vec(view_port.x - position.x * parallax,
  89                            view_port.y - position.y * parallax),
  90                        &min_x, &min_y);
  91
  92         int max_x = 0, max_y = 0;
  93         chunk_of_point(vec(view_port.x - position.x * parallax + view_port.w,
  94                            view_port.y - position.y * parallax + view_port.h),
  95                        &max_x, &max_y);
  96
  97         for (int x = min_x; x <= max_x; ++x) {
  98             for (int y = min_y; y <= max_y; ++y) {
  99                 if (render_chunk(
 100                         background,
 101                         camera,
 102                         x, y,
 103                         color_darker(background->base_color, 0.05f * (float)(l + 1)),
 104                         position,
 105                         parallax) < 0) {
 106                     return -1;
 107                 }
 108             }
 109         }
 110     }
 111
 112     return 0;
 113 }
 114
 115 /* Private Function */
 116
 117 static void chunk_of_point(Point p, int *x, int *y)
 118 {
 119     trace_assert(x);
 120     trace_assert(y);
 121     *x = (int) (p.x / BACKGROUND_CHUNK_WIDTH);
 122     *y = (int) (p.y / BACKGROUND_CHUNK_HEIGHT);
 123 }
 124
 125 int render_chunk(const Background *background,
 126                  Camera *camera,
 127                  int chunk_x, int chunk_y,
 128                  Color color,
 129                  Vec position,
 130                  float parallax)
 131 {
 132     (void) background;
 133
 134     if (background->debug_mode) {
 135         return 0;
 136     }
 137
 138     srand((unsigned int)(roundf((float)chunk_x + (float)chunk_y + parallax)));
 139
 140     for (size_t i = 0; i < BACKGROUND_CHUNK_COUNT; ++i) {
 141         const float rect_x = rand_float_range((float) chunk_x * BACKGROUND_CHUNK_WIDTH,
 142                                               (float) (chunk_x + 1) * BACKGROUND_CHUNK_WIDTH);
 143         const float rect_y = rand_float_range((float) chunk_y * BACKGROUND_CHUNK_HEIGHT,
 144                                               (float) (chunk_y + 1) * BACKGROUND_CHUNK_HEIGHT);
 145         const float rect_w = rand_float_range(0.0f, BACKGROUND_CHUNK_WIDTH * 0.5f);
 146         const float rect_h = rand_float_range(rect_w * 0.5f, rect_w * 1.5f);
 147
 148         if (camera_fill_rect(
 149                 camera,
 150                 rect(rect_x + position.x * parallax,
 151                      rect_y + position.y * parallax,
 152                      rect_w,
 153                      rect_h),
 154                 color) < 0) {
 155             return -1;
 156         }
 157     }
 158
 159     return 0;
 160 }
 161
 162 void background_toggle_debug_mode(Background *background)
 163 {
 164     background->debug_mode = !background->debug_mode;
 165 }