src/game/level/background.c

   1 #include <stdio.h>
   2
   3 #include "game/level/background.h"
   4 #include "math/rand.h"
   5 #include "math/rect.h"
   6 #include "system/lt.h"
   7 #include "system/nth_alloc.h"
   8 #include "system/log.h"
   9 #include "system/stacktrace.h"
  10 #include "config.h"
  11
  12 static inline
  13 Vec2i chunk_of_point(Vec2f p)
  14 {
  15     return vec2i(
  16         (int) floorf(p.x / BACKGROUND_CHUNK_WIDTH),
  17         (int) floorf(p.y / BACKGROUND_CHUNK_HEIGHT));
  18 }
  19
  20 int render_chunk(const Camera *camera,
  21                  Vec2i chunk,
  22                  Color color);
  23
  24 int background_render(const Background *background,
  25                       const Camera *camera0)
  26 {
  27     trace_assert(background);
  28     trace_assert(camera0);
  29
  30     Camera camera = *camera0;
  31
  32     if (camera_clear_background(
  33             &camera,
  34             background->base_color) < 0) {
  35         return -1;
  36     }
  37
  38     camera.scale = 1.0f - BACKGROUND_LAYERS_STEP * BACKGROUND_LAYERS_COUNT;
  39
  40     for (int l = 0; l < BACKGROUND_LAYERS_COUNT; ++l) {
  41         const Rect view_port = camera_view_port(&camera);
  42         const Vec2f position = vec(view_port.x, view_port.y);
  43
  44         Vec2i min = chunk_of_point(position);
  45         Vec2i max = chunk_of_point(vec_sum(position, vec(view_port.w, view_port.h)));
  46
  47         for (int x = min.x - 1; x <= max.x; ++x) {
  48             for (int y = min.y - 1; y <= max.y; ++y) {
  49                 if (render_chunk(
  50                         &camera,
  51                         vec2i(x, y),
  52                         color_darker(background->base_color, 0.05f * (float)(l + 1))) < 0) {
  53                     return -1;
  54                 }
  55             }
  56         }
  57
  58         camera.scale += BACKGROUND_LAYERS_STEP;
  59     }
  60
  61     return 0;
  62 }
  63
  64 /* Private Function */
  65
  66 int render_chunk(const Camera *camera,
  67                  Vec2i chunk,
  68                  Color color)
  69 {
  70     trace_assert(camera);
  71
  72     if (camera->debug_mode) {
  73         return 0;
  74     }
  75
  76     srand((unsigned int)(roundf((float)chunk.x + (float)chunk.y + camera->scale * 10.0f)));
  77
  78     for (size_t i = 0; i < BACKGROUND_TURDS_PER_CHUNK; ++i) {
  79         const float rect_x = rand_float_range(0.0f, BACKGROUND_CHUNK_WIDTH);
  80         const float rect_y = rand_float_range(0.0f, BACKGROUND_CHUNK_HEIGHT);
  81
  82         const float rect_w = rand_float_range(0.0f, BACKGROUND_CHUNK_WIDTH * 0.5f);
  83         const float rect_h = rand_float_range(rect_w * 0.5f, rect_w * 1.5f);
  84
  85         if (camera_fill_rect(
  86                 camera,
  87                 rect((float) chunk.x * BACKGROUND_CHUNK_WIDTH + rect_x,
  88                      (float) chunk.y * BACKGROUND_CHUNK_HEIGHT + rect_y,
  89                      rect_w,
  90                      rect_h),
  91                 color) < 0) {
  92             return -1;
  93         }
  94     }
  95
  96     return 0;
  97 }
  98
  99 Color background_base_color(const Background *background)
 100 {
 101     return background->base_color;
 102 }