From 9c379602836d6cc4ad276ff90831668f6339ca89 Mon Sep 17 00:00:00 2001
From: "Zed A. Shaw" <zed.shaw@gmail.com>
Date: Mon, 10 Feb 2025 12:05:07 -0500
Subject: [PATCH] Raycaster mostly cleaned up.  Only thing I can think of is
 bringing in CameraLOL as the coordinates directly.

---
 raycaster.cpp | 24 +++++++++++++++---------
 raycaster.hpp |  2 ++
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/raycaster.cpp b/raycaster.cpp
index 14a6571..7fa2918 100644
--- a/raycaster.cpp
+++ b/raycaster.cpp
@@ -47,6 +47,8 @@ Raycaster::Raycaster(TexturePack &textures, int width, int height) :
 }
 
 void Raycaster::set_position(int x, int y) {
+  $screen_pos_x = x;
+  $screen_pos_y = y;
   $view_sprite.setPosition({(float)x, (float)y});
 }
 
@@ -81,8 +83,8 @@ void Raycaster::sprite_casting(sf::RenderTarget &target) {
     double inv_det = 1.0 / ($plane_x * $dir_y - $dir_x * $plane_y); // required for correct matrix multiplication
 
     double transform_x = inv_det * ($dir_y * sprite_x - $dir_x * sprite_y);
-    //this is actually the depth inside the screen, that what Z is in 3D, the distance of sprite to player, matching sqrt(spriteDistance[i])
 
+    //this is actually the depth inside the screen, that what Z is in 3D, the distance of sprite to player, matching sqrt(spriteDistance[i])
     double transform_y = inv_det * (-$plane_y * sprite_x + $plane_x * sprite_y);
 
     int sprite_screen_x = int(($width / 2) * (1 + transform_x / transform_y));
@@ -119,10 +121,12 @@ void Raycaster::sprite_casting(sf::RenderTarget &target) {
 
       int tex_x = int(texture_width * (draw_start_x - (-sprite_width / 2 + sprite_screen_x)) * texture_width / sprite_width) / texture_width;
       int tex_render_width = tex_x_end - tex_x;
+
+      // avoid drawing sprites that are not visible (width < 0)
       if(tex_render_width <= 0) continue;
 
-      float x = float(draw_start_x + RAY_VIEW_X);
-      float y = float(draw_start_y + RAY_VIEW_Y);
+      float x = float(draw_start_x + $screen_pos_x);
+      float y = float(draw_start_y + $screen_pos_y);
       float sprite_w = float(sprite_width) / float(texture_width);
       float sprite_h = float(sprite_height) / float(texture_height);
 
@@ -135,6 +139,9 @@ void Raycaster::sprite_casting(sf::RenderTarget &target) {
 
       $brightness.setUniform("offsetFactor", sf::Glsl::Vec2{0.0f, 0.0f});
 
+      // the SpatialMap.distance_sorted only calculates the
+      // (x1-x2)^2 + (y1-y2)^2 portion of distance, so to get
+      // the actual distance we need to sqrt that.
       float level = sqrt(rec.first);
       $brightness.setUniform("darkness", level);
       target.draw(*sf_sprite, &$brightness);
@@ -158,10 +165,6 @@ void Raycaster::cast_rays() {
     int map_x = int($pos_x);
     int map_y = int($pos_y);
 
-    // length of ray from current pos to next x or y-side
-    double side_dist_x;
-    double side_dist_y;
-
     // length of ray from one x or y-side to next x or y-side
     double delta_dist_x = std::abs(1.0 / ray_dir_x);
     double delta_dist_y = std::abs(1.0 / ray_dir_y);
@@ -171,7 +174,10 @@ void Raycaster::cast_rays() {
     int hit = 0;
     int side = 0;
 
-    // calculate step and initial sideDist
+    // length of ray from current pos to next x or y-side
+    double side_dist_x;
+    double side_dist_y;
+
     if(ray_dir_x < 0) {
       step_x = -1;
       side_dist_x = ($pos_x - map_x) * delta_dist_x;
@@ -226,7 +232,7 @@ void Raycaster::cast_rays() {
     } else {
       wall_x = $pos_x + perp_wall_dist * ray_dir_x;
     }
-    wall_x -= floor((wall_x));
+    wall_x -= floor(wall_x);
 
     // x coorindate on the texture
     int tex_x = int(wall_x * double(texture_width));
diff --git a/raycaster.hpp b/raycaster.hpp
index 2c67dd9..50626b5 100644
--- a/raycaster.hpp
+++ b/raycaster.hpp
@@ -32,6 +32,8 @@ struct Raycaster {
 
   int $width;
   int $height;
+  int $screen_pos_x = RAY_VIEW_X;
+  int $screen_pos_y = RAY_VIEW_Y;
   GameLevel $level;
   Matrix $map;
   std::unordered_map<DinkyECS::Entity, SpriteTexture> $sprites;