From 6a94c79ac2decf26efcd59b2b16a2834aaec7f12 Mon Sep 17 00:00:00 2001
From: Fabien Freling <public@ffreling.com>
Date: Thu, 26 Jun 2014 23:45:02 +0200
Subject: [PATCH] FIll new interpolated pixels.

- Take input image in argument.
- Allow set_pixel() out of bounds, noop.
---
 TODO.md      |  2 ++
 rotation.cpp | 38 ++++++++++++++++++++++++--------------
 2 files changed, 26 insertions(+), 14 deletions(-)

diff --git a/TODO.md b/TODO.md
index 7b39a59..a867faa 100644
--- a/TODO.md
+++ b/TODO.md
@@ -3,4 +3,6 @@
 [X] Use atan2 at beginning and end of line.
     Interpolation in-between values
 [X] Test pixel perfect 90
+[ ] Fix out-of-bounds pixel set
+
 [ ] Optimization for square images?
diff --git a/rotation.cpp b/rotation.cpp
index ed8bf08..45abad3 100644
--- a/rotation.cpp
+++ b/rotation.cpp
@@ -104,9 +104,10 @@ struct Image {
   {
     if (x >= width || y >= height)
     {
-        cerr << "Point (" << x << ", " << y << ") out of bounds" << endl;
+        cerr << __LINE__ << " | Point (" << x << ", " << y << ") out of bounds" << endl;
         cerr << " Image dimensions: " << width << " x " << height << endl;
-        assert(false);
+//        assert(false);
+        return;
     }
     int const index = y * width + x;
     r_chan[index] = r;
@@ -501,13 +502,11 @@ Image rotate(Image const& src, double angle)
   int origin_nb_steps = max(abs(bl.x - tl.x), abs(bl.y - tl.y));
   double origin_y_inc = (src_bl.y - src_tl.y) / origin_nb_steps;
   double origin_x_inc = (src_bl.x - src_tl.x) / origin_nb_steps;
-  //cout << " origin steps: " << origin_nb_steps << " (" << origin_x_inc << ", " << origin_y_inc << ")" << endl;
 
   // steps for line in source image
   int line_nb_steps = max(abs(tr.x - tl.x), abs(tr.y - tl.y));
   double line_y_inc = (src_tr.y - src_tl.y) / line_nb_steps;
   double line_x_inc = (src_tr.x - src_tl.x) / line_nb_steps;
-  //cout << " line steps: " << line_nb_steps << " (" << line_x_inc << ", " << line_y_inc << ")" << endl;
 
   // steps for first column in rotated image
   double rotated_y_inc = (bl.y - tl.y) / (float) origin_nb_steps;
@@ -515,7 +514,6 @@ Image rotate(Image const& src, double angle)
 
   // steps for line in rotated image
   DPoint bresenham((tr.x - tl.x) / (float) line_nb_steps, (tr.y - tl.y) / (float) line_nb_steps);
-  cout << "bresenham: " << bresenham << endl;
 
   for (int y_i = 0; y_i <= (int) origin_nb_steps; ++y_i)
   {
@@ -523,6 +521,8 @@ Image rotate(Image const& src, double angle)
     DPoint const src_origin(src_tl.x + y_i * origin_x_inc, src_tl.y + y_i * origin_y_inc);
     APoint const rot_origin(tl.x + y_i * rotated_x_inc, tl.y + y_i * rotated_y_inc);
 
+    APoint previous = rot_origin;
+
     for (int x_i = 0; x_i <= (int) line_nb_steps; ++x_i)
     {
       DPoint const src_rotated_point(src_origin.x + x_i * line_x_inc, src_origin.y + x_i * line_y_inc);
@@ -546,6 +546,13 @@ Image rotate(Image const& src, double angle)
       // TODO: bypass variables, access src pixels
       src.get_pixel(src_p, r, g, b);
       rotated.set_pixel(rot_point, r, g, b);
+
+      // Fill missing points, created by interpolation
+      if (previous.x != rot_point.x && previous.y != rot_point.y)
+      {
+        rotated.set_pixel(APoint(rot_point.x, previous.y), r, g, b);
+      }
+      previous = rot_point;
     }
   }
 
@@ -677,9 +684,9 @@ void check_lines()
   draw_outline(rect1, 90, "rect1");
 }
 
-bool check_90()
+bool check_90(string const& path)
 {
-  Image const src("img/lena.ppm");
+  Image const src(path);
   Image const rotated = rotate(src, 90);
 
   for (unsigned int y = 0; y < rotated.height; ++y)
@@ -708,8 +715,14 @@ bool check_90()
 // Main
 //
 
-int main()
+int main(int argc, char* argv[])
 {
+  if (argc < 2)
+  {
+    cout << "Usage: " << argv[0] << " image.ppm" << endl;
+    return 1;
+  }
+
   bool perform_check = true;
 
   if (perform_check)
@@ -722,19 +735,16 @@ int main()
 
     //check_lines();
 
-    if (!check_90())
+    if (false && !check_90(argv[1]))
     {
       cerr << __LINE__ << " | 90 degrees check failed" << endl;
       return 1;
     }
   }
 
-  //Image img("img/luigi.ppm");
-  //Image img("img/wallpaper.ppm");
-  Image img("img/mini_lena.ppm");
+  Image img(argv[1]);
 
-  //for (double rotation : {0, 1, 5, 15, 30, 45, 60, 75, 90, 110, 140, 160, 180, 200, 210, 235, 260, 270, 300, 315, 355, 359})
-  for (double rotation : {0, 45, 90})
+  for (double rotation = 0; rotation <= 360; rotation += 5)
   {
     auto const before = chrono::high_resolution_clock::now();