1 files changed, 271 insertions, 0 deletions

diff --git a/src/spotlight.c b/src/spotlight.c
new file mode 100644
index 0000000..ae45a93
--- /dev/null
+++ b/src/spotlight.c
@@ -0,0 +1,271 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <raylib.h>
+#include <raymath.h>
+#include "spotlight.frag.c"
+
+#define KEY_MOD_ROTATION KEY_LEFT_ALT
+#define KEY_MOD_RADIUS   KEY_CAPS_LOCK
+
+// NOTE(cmmm): GetMousePosition returns actual value only after
+// certain amount of frames
+#define STARTUP_FRAME_COUNT 3
+
+#define SPOTLIGHT_SPEED_MAX  2000
+
+#define SPOTLIGHT_TARGET_INITIAL_ZOOM     1
+#define SPOTLIGHT_TARGET_INITIAL_ROTATION 0
+#define SPOTLIGHT_TARGET_INITIAL_FOCUSED  false
+
+#define SPOTLIGHT_ROTATION_MULTIPLIER 45
+#define SPOTLIGHT_ROTATION_SPEED_MAX  180
+
+#define SPOTLIGHT_ZOOM_SPEED_MAX       4
+#define SPOTLIGHT_ZOOM_MIN             1
+#define SPOTLIGHT_ZOOM_MAX            64
+
+#define SPOTLIGHT_RADIUS_MULTIPLIER 50
+#define SPOTLIGHT_RADIUS_SPEED_MAX  10
+#define SPOTLIGHT_RADIUS_MIN       100
+
+#define SPOTLIGHT_DIMNESS_MIN .25
+#define SPOTLIGHT_DIMNESS_MAX .75
+
+#define SPOTLIGHT_FOCUS_SPEED_MAX 2000
+
+#define END_DURATION (.5)
+
+#define EXECLP(P, ...) execlp ((P), (P), __VA_ARGS__, NULL)
+
+static Texture2D screenshot;
+
+
+static Vector2 translation_target = {0};
+static Vector2 spotlight_pos;
+static Vector2 spotlight_pos_initial;
+static float   spotlight_radius;
+static bool    spotlight_focused         = SPOTLIGHT_TARGET_INITIAL_FOCUSED;
+static float   spotlight_target_zoom     = SPOTLIGHT_TARGET_INITIAL_ZOOM;
+static float   spotlight_target_rotation = SPOTLIGHT_TARGET_INITIAL_ROTATION;
+static float   spotlight_target_radius;
+static Vector2 spotlight_target_pos;
+static float spotlight_radius_unfocused;
+static float spotlight_radius_initial_focused;
+
+static Shader shader;
+static int shader_location_target;
+static int shader_location_dimness;
+static int shader_location_radius;
+
+static Camera2D camera = {
+    .rotation = 0,
+    .zoom     = 1,
+};
+
+static Vector2 screen_size = {0};
+static float frame_time;
+
+static void
+update_frame_info (void)
+{
+  frame_time = GetFrameTime ();
+  if (screen_size.x != GetScreenWidth  () ||
+      screen_size.y != GetScreenHeight ()) {
+    screen_size.x = GetScreenWidth  ();
+    screen_size.y = GetScreenHeight ();
+
+    spotlight_radius_unfocused = Vector2Length (screen_size);
+    spotlight_radius_initial_focused = fminf (screen_size.x, screen_size.y)/2;
+  }
+}
+
+static void
+handle_input (void)
+{
+  spotlight_target_pos = GetMousePosition ();
+
+  if (IsMouseButtonDown (MOUSE_BUTTON_RIGHT))
+    translation_target = Vector2Add (translation_target, GetMouseDelta ());
+
+  float wheel_move = GetMouseWheelMove ();
+  if (wheel_move) {
+    if (IsKeyDown (KEY_MOD_ROTATION)) {
+      spotlight_target_rotation += SPOTLIGHT_ROTATION_MULTIPLIER*wheel_move;
+    } else if (IsKeyDown (KEY_MOD_RADIUS)) {
+      if (!spotlight_focused) {
+        spotlight_focused = true;
+        spotlight_target_radius = spotlight_radius_initial_focused;
+        HideCursor ();
+      }
+
+      spotlight_target_radius += SPOTLIGHT_RADIUS_MULTIPLIER*wheel_move;
+      float spotlight_radius_max = spotlight_radius_unfocused;
+      spotlight_target_radius = Clamp (spotlight_target_radius,
+                                       SPOTLIGHT_RADIUS_MIN,
+                                       spotlight_radius_max);
+    } else {
+      float scale_factor = 1 + fabsf (wheel_move)/4;
+      if (!signbit (wheel_move)) scale_factor = 1/scale_factor;
+      spotlight_target_zoom = Clamp (spotlight_target_zoom*scale_factor,
+                                     SPOTLIGHT_ZOOM_MIN,
+                                     SPOTLIGHT_ZOOM_MAX);
+    }
+  }
+
+  if (IsKeyPressed (KEY_F)) {
+    spotlight_focused ^= 1;
+    if (spotlight_focused) {
+      spotlight_target_radius = spotlight_radius_initial_focused;
+      HideCursor ();
+    } else
+      ShowCursor ();
+  }
+}
+
+static void
+update (void)
+{
+  spotlight_pos = Vector2MoveTowards (spotlight_pos, spotlight_target_pos,
+                                      SPOTLIGHT_SPEED_MAX*frame_time);
+
+  Vector2 translation_delta = Vector2MoveTowards (translation_delta, translation_target,
+                                                  SPOTLIGHT_SPEED_MAX*frame_time);
+  translation_target = Vector2Subtract (translation_target, translation_delta);
+  Vector2 delta_target = Vector2Rotate (Vector2Scale (translation_delta,
+                                                      -1/camera.zoom),
+                                        -camera.rotation*DEG2RAD);
+  camera.target = Vector2Add (camera.target, delta_target);
+
+
+  if (!spotlight_focused) {
+    spotlight_target_radius = spotlight_radius_unfocused;
+  }
+
+  camera.rotation += Clamp (spotlight_target_rotation - camera.rotation,
+                            -SPOTLIGHT_ROTATION_SPEED_MAX*frame_time,
+                            +SPOTLIGHT_ROTATION_SPEED_MAX*frame_time);
+
+  camera.zoom += Clamp (spotlight_target_zoom - camera.zoom,
+                        -SPOTLIGHT_ZOOM_SPEED_MAX*frame_time,
+                        +SPOTLIGHT_ZOOM_SPEED_MAX*frame_time);
+  camera.target = GetScreenToWorld2D (spotlight_pos, camera);
+  camera.offset = spotlight_pos;
+
+  spotlight_radius += Clamp (spotlight_target_radius - spotlight_radius,
+                             -SPOTLIGHT_FOCUS_SPEED_MAX*frame_time,
+                             +SPOTLIGHT_FOCUS_SPEED_MAX*frame_time);
+}
+
+static void
+draw (void)
+{
+  Vector2 target = { spotlight_pos.x, screen_size.y - spotlight_pos.y, };
+  float dimness = Remap (spotlight_radius,
+                         spotlight_radius_initial_focused,
+                         SPOTLIGHT_RADIUS_MIN,
+                         SPOTLIGHT_DIMNESS_MIN,
+                         SPOTLIGHT_DIMNESS_MAX);
+  SetShaderValue (shader, shader_location_target,  &target,           SHADER_UNIFORM_VEC2);
+  SetShaderValue (shader, shader_location_dimness, &dimness,          SHADER_UNIFORM_FLOAT);
+  SetShaderValue (shader, shader_location_radius,  &spotlight_radius, SHADER_UNIFORM_FLOAT);
+
+  BeginDrawing (); {
+    ClearBackground (BLANK);
+    BeginMode2D (camera); {
+      BeginShaderMode (shader); {
+        DrawTextureV (screenshot, Vector2Zero (), WHITE);
+      } EndShaderMode ();
+    } EndMode2D ();
+  } EndDrawing ();
+}
+
+int
+main (int argc, char *argv[])
+{
+  char tmpname[] = "/tmp/spotlight.png";
+  // {
+  //   int tmp_fd;
+  //   do tmp_fd = mkstemp (tmpname);
+  //   while (tmp_fd == -1);
+  //   close (tmp_fd);
+  // }
+
+  {
+    pid_t grim_pid = fork ();
+    if (!grim_pid) EXECLP ("grim", tmpname);
+    int grim_exit_status;
+    waitpid (grim_pid, &grim_exit_status, 0);
+    if (grim_exit_status) {
+      TraceLog (LOG_ERROR, "GRIM: Unable to capture screenshot (%s)", tmpname);
+      exit (EXIT_FAILURE);
+    } TraceLog (LOG_INFO, "GRIM: Screenshot captured (%s)", tmpname);
+  }
+
+  SetConfigFlags (FLAG_FULLSCREEN_MODE |
+                  FLAG_MSAA_4X_HINT |
+                  FLAG_WINDOW_UNDECORATED |
+                  FLAG_VSYNC_HINT);
+  InitWindow (0, 0, NULL);
+  SetMouseCursor (MOUSE_CURSOR_CROSSHAIR);
+  screenshot = LoadTexture (tmpname);
+
+  // shader = LoadShader (NULL, "./spotlight.frag");
+  shader = LoadShaderFromMemory (NULL, (void *) SPOTLIGHT_FRAG_DATA);
+  shader_location_target  = GetShaderLocation (shader, "target");
+  shader_location_dimness = GetShaderLocation (shader, "dimness");
+  shader_location_radius  = GetShaderLocation (shader, "radius");
+
+  spotlight_radius =
+    Vector2Length ((Vector2) { GetScreenWidth (), GetScreenHeight () });
+  for (int i = 0; i < STARTUP_FRAME_COUNT; ++i) draw ();
+  spotlight_pos = spotlight_pos_initial = GetMousePosition ();
+  camera.target = GetScreenToWorld2D (spotlight_pos, camera);
+  camera.offset =                     spotlight_pos;
+  while (!WindowShouldClose ()) {
+    update_frame_info ();
+    handle_input ();
+    update ();
+    draw   ();
+  }
+
+  Vector2 camera_target = GetMousePosition ();
+  Camera2D start_camera = camera;
+  float start_spotlight_radius = spotlight_radius;
+  float distances[5] = {
+    Remap (Vector2Distance (start_camera.target, camera_target), 0, Vector2Length (screen_size), 0, 1),
+    Remap (Vector2Distance (start_camera.offset, camera_target), 0, Vector2Length (screen_size), 0, 1),
+    start_camera.rotation/SPOTLIGHT_ROTATION_MULTIPLIER,
+    Remap (start_camera.zoom, SPOTLIGHT_ZOOM_MIN, SPOTLIGHT_ZOOM_MAX, 0, 1),
+    Remap (start_spotlight_radius - spotlight_radius_unfocused, 0, spotlight_radius_unfocused - SPOTLIGHT_RADIUS_MIN, 0, 1),
+  };
+  float max_distance = 0;
+  for (int i = 0; i < 5; ++i) {
+    if (distances[i] > max_distance)
+      max_distance = distances[i];
+  }
+
+  if (max_distance) {
+    float end_speed = 4/(1 + fminf ( max_distance, 1));
+    for (float progress  = end_speed*frame_time; progress < 1
+      ;        progress += end_speed*frame_time) {
+      update_frame_info ();
+
+      Vector2 spotlight_pos_world = GetScreenToWorld2D (spotlight_pos, camera);
+      camera.target    = Vector2Lerp (start_camera.target,                 camera_target,  progress);
+      camera.offset    = Vector2Lerp (start_camera.offset,                 camera_target,  progress);
+      camera.rotation  =        Lerp (start_camera.rotation,                           0,  progress);
+      camera.zoom      =        Lerp (start_camera.zoom,                               1,  progress);
+      spotlight_radius =        Lerp (start_spotlight_radius, spotlight_radius_unfocused, progress);
+      spotlight_pos = GetWorldToScreen2D (spotlight_pos_world, camera);
+
+      draw ();
+    }
+  }
+
+  UnloadTexture (screenshot);
+  CloseWindow ();
+
+  return EXIT_SUCCESS;
+}