From 7b07f66bfba5d33581b9cb00a1e3cfd966001a85 Mon Sep 17 00:00:00 2001
From: augustin64 <me.git@augustin64.fr>
Date: Thu, 3 Apr 2025 08:48:38 +0200
Subject: [PATCH] Add --until-mask-removal

Are all seams contributing to mask ?
---
 src/seam-carving.cpp | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/src/seam-carving.cpp b/src/seam-carving.cpp
index d840206..6891f07 100644
--- a/src/seam-carving.cpp
+++ b/src/seam-carving.cpp
@@ -12,9 +12,12 @@
 #include <SimpleProgressBar.hpp>
 #include <stb_image_write.h>
 
+#define DEFAULT_SEAMS 1
+
 // Global flags
 bool silent = false;
 bool test_energy = false;
+bool until_mask_removal = false;
 int max_step = 1;
 
 // Get index for any table indexed by [width*(i : height) + (j : width)], but a
@@ -310,6 +313,18 @@ std::vector<std::pair<int, float>> mask_energy(std::vector<float> energy,
   return output;
 }
 
+bool does_seam_remove_mask(unsigned char* mask, int width, int height, int nbChannels,
+                          std::vector<int> opt_seam, bool vertical)
+{
+  int dim_large = vertical ? width : height;
+  int dim_long = vertical ? height : width;
+
+  for (int i=0; i < dim_long; i++) {
+    if (mask[im_index(i, opt_seam[i])] == 0) return true;
+  }
+  return false;
+}
+
 void seam_carving(unsigned char *source, int width, int height, int nbChannels,
                   const char *out_filename, int nbSeams, bool vertical, unsigned char* mask=nullptr) {
   int nbColorChannels = nbChannels > 3 ? 3 : nbChannels;
@@ -384,16 +399,23 @@ void seam_carving(unsigned char *source, int width, int height, int nbChannels,
     }
   }
 
-  SimpleProgressBar::ProgressBar bar(nbSeams);
+  SimpleProgressBar::ProgressBar bar(until_mask_removal ? dim_large : nbSeams);
   bar.print();
 
-  for (auto seam_index = 0; seam_index < nbSeams; seam_index++) {
+  auto seam_index = 0;
+  while (seam_index++ < nbSeams || until_mask_removal) {
     std::vector<int> opt_seam;
     if (mask) {
       opt_seam = carving_step(
         source_img, masked_energy, output_img, output_masked_energy,
         curWidth, curHeight, nbChannels, nbColorChannels, vertical
       );
+
+      if (
+        until_mask_removal &&
+        !does_seam_remove_mask(mask, width, height, nbChannels, opt_seam, vertical)
+      ) break;
+
     } else {
       opt_seam = carving_step(
         source_img, source_energy, output_img, output_energy,
@@ -446,7 +468,7 @@ int main(int argc, char **argv) {
   std::string maskImage;
   std::string sourceImage;
   std::string outputImage = "output.png";
-  int nbSeams = 1;
+  int nbSeams = DEFAULT_SEAMS;
   bool vertical = false;
 
   app.add_option("-s,--source", sourceImage, "Source image")
@@ -466,6 +488,8 @@ int main(int argc, char **argv) {
   app.add_flag("--silent", silent, "No verbose messages");
   app.add_flag("--test-energy", test_energy,
                "Don't resize image, just try the specified energy function");
+  app.add_flag("-u,--until-mask-removal", until_mask_removal,
+               "Carve the image until there are no more red pixels in the mask");
   CLI11_PARSE(app, argc, argv);
 
   // Image loading
@@ -504,6 +528,14 @@ int main(int argc, char **argv) {
       //* . (2) we want to keep the pixel
       //* . (1) nothing in particular
       //* . (0) we want to remove the pixel
+  } 
+  if (until_mask_removal && maskImage.empty()) {
+    std::cerr << "Flag --until-mask-removal but no mask provided." << std::endl;
+    until_mask_removal = false;
+  }
+  if (until_mask_removal && nbSeams != DEFAULT_SEAMS) {
+    std::cerr << "Flag --nb-seams specified but --until-mask-removal provided." << std::endl;
+    nbSeams = DEFAULT_SEAMS;
   }
 
   nbSeams = std::min(nbSeams, vertical ? width-1 : height-1); // We want to keep at least one row or column