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/line_stream.h"
   7 #include "system/lt.h"
   8 #include "system/nth_alloc.h"
   9 #include "system/log.h"
  10 #include "system/stacktrace.h"
  11 #include "config.h"
  12
  13 static inline
  14 Vec2i chunk_of_point(Vec2f p)
  15 {
  16     return vec2i(
  17         (int) floorf(p.x / BACKGROUND_CHUNK_WIDTH),
  18         (int) floorf(p.y / BACKGROUND_CHUNK_HEIGHT));
  19 }
  20
  21 int render_chunk(const Camera *camera,
  22                  Vec2i chunk,
  23                  Color color);
  24
  25 int background_render(const Background *background,
  26                       const Camera *camera0)
  27 {
  28     trace_assert(background);
  29     trace_assert(camera0);
  30
  31     Camera camera = *camera0;
  32
  33     if (camera_clear_background(
  34             &camera,
  35             background->base_color) < 0) {
  36         return -1;
  37     }
  38
  39     camera.scale = 1.0f - BACKGROUND_LAYERS_STEP * BACKGROUND_LAYERS_COUNT;
  40
  41     for (int l = 0; l < BACKGROUND_LAYERS_COUNT; ++l) {
  42         const Rect view_port = camera_view_port(&camera);
  43         const Vec2f position = vec(view_port.x, view_port.y);
  44
  45         Vec2i min = chunk_of_point(position);
  46         Vec2i max = chunk_of_point(vec_sum(position, vec(view_port.w, view_port.h)));
  47
  48         for (int x = min.x - 1; x <= max.x; ++x) {
  49             for (int y = min.y - 1; y <= max.y; ++y) {
  50                 if (render_chunk(
  51                         &camera,
  52                         vec2i(x, y),
  53                         color_darker(background->base_color, 0.05f * (float)(l + 1))) < 0) {
  54                     return -1;
  55                 }
  56             }
  57         }
  58
  59         camera.scale += BACKGROUND_LAYERS_STEP;
  60     }
  61
  62     return 0;
  63 }
  64
  65 /* Private Function */
  66
  67 int render_chunk(const Camera *camera,
  68                  Vec2i chunk,
  69                  Color color)
  70 {
  71     trace_assert(camera);
  72
  73     if (camera->debug_mode) {
  74         return 0;
  75     }
  76
  77     srand((unsigned int)(roundf((float)chunk.x + (float)chunk.y + camera->scale * 10.0f)));
  78
  79     for (size_t i = 0; i < BACKGROUND_TURDS_PER_CHUNK; ++i) {
  80         const float rect_x = rand_float_range(0.0f, BACKGROUND_CHUNK_WIDTH);
  81         const float rect_y = rand_float_range(0.0f, BACKGROUND_CHUNK_HEIGHT);
  82
  83         const float rect_w = rand_float_range(0.0f, BACKGROUND_CHUNK_WIDTH * 0.5f);
  84         const float rect_h = rand_float_range(rect_w * 0.5f, rect_w * 1.5f);
  85
  86         if (camera_fill_rect(
  87                 camera,
  88                 rect((float) chunk.x * BACKGROUND_CHUNK_WIDTH + rect_x,
  89                      (float) chunk.y * BACKGROUND_CHUNK_HEIGHT + rect_y,
  90                      rect_w,
  91                      rect_h),
  92                 color) < 0) {
  93             return -1;
  94         }
  95     }
  96
  97     return 0;
  98 }
  99
 100 Color background_base_color(const Background *background)
 101 {
 102     return background->base_color;
 103 }