added tutorial 107 for screen capture and texturing

cleaned up the PNG functions


Former-commit-id: 7e2a9dc8a26f49474d10726e773410090f69dab7

include/igl/png/readPNG.cpp

@@ -0,0 +1,47 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Daniele Panozzo <daniele.panozzo@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "readPNG.h"
+#include <stb_image.h>
+
+IGL_INLINE bool igl::png::readPNG(
+  const std::string png_file,
+  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& R,
+  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& G,
+  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& B,
+  Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& A
+)
+{
+  int cols,rows,n;
+  unsigned char *data = stbi_load(png_file.c_str(), &cols, &rows, &n, 4);
+  if(data == NULL) {
+    return false;
+  }
+
+  R.resize(cols,rows);
+  G.resize(cols,rows);
+  B.resize(cols,rows);
+  A.resize(cols,rows);
+
+  for (unsigned i=0; i<rows; ++i) {
+    for (unsigned j=0; j<cols; ++j) {
+      R(j,rows-1-i) = data[4*(j + cols * i) + 0];
+      G(j,rows-1-i) = data[4*(j + cols * i) + 1];
+      B(j,rows-1-i) = data[4*(j + cols * i) + 2];
+      A(j,rows-1-i) = data[4*(j + cols * i) + 3];
+    }
+  }
+
+  stbi_image_free(data);
+
+  return true;
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template specialization
+// generated by autoexplicit.sh
+#endif

include/igl/png/readPNG.h

@@ -0,0 +1,39 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Daniele Panozzo <daniele.panozzo@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_PNG_READ_PNG_H
+#define IGL_PNG_READ_PNG_H
+#include "../igl_inline.h"
+#include <Eigen/Core>
+#include <string>
+
+namespace igl
+{
+  namespace png
+  {
+    // Read an image from a .png file into 4 memory buffers
+    //
+    // Input:
+    //  png_file  path to .png file
+    // Output:
+    //  R,G,B,A texture channels
+    // Returns true on success, false on failure
+    //
+    IGL_INLINE bool readPNG(const std::string png_file,
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& R,
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& G,
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& B,
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& A
+    );
+  }
+}
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "readPNG.cpp"
+#endif
+
+#endif

include/igl/png/writePNG.cpp

@@ -0,0 +1,47 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Daniele Panozzo <daniele.panozzo@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#include "writePNG.h"
+#include <stb_image_write.h>
+#include <vector>
+
+IGL_INLINE bool igl::png::writePNG(
+  const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& R,
+  const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& G,
+  const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& B,
+  const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& A,
+  const std::string png_file
+)
+{
+  assert((R.rows() == G.rows()) && (G.rows() == B.rows()) && (B.rows() == A.rows()));
+  assert((R.cols() == G.cols()) && (G.cols() == B.cols()) && (B.cols() == A.cols()));
+
+  const int comp = 4;                                  // 4 Channels Red, Green, Blue, Alpha
+  const int stride_in_bytes = R.rows()*comp;           // Lenght of one row in bytes
+  std::vector<unsigned char> data(R.size()*comp,0);     // The image itself;
+
+  for (unsigned i = 0; i<R.rows();++i)
+  {
+    for (unsigned j = 0; j < R.cols(); ++j)
+    {
+        data[(j * R.rows() * comp) + (i * comp) + 0] = R(i,R.cols()-1-j);
+        data[(j * R.rows() * comp) + (i * comp) + 1] = G(i,R.cols()-1-j);
+        data[(j * R.rows() * comp) + (i * comp) + 2] = B(i,R.cols()-1-j);
+        data[(j * R.rows() * comp) + (i * comp) + 3] = A(i,R.cols()-1-j);
+    }
+  }
+
+  stbi_write_png(png_file.c_str(), R.rows(), R.cols(), comp, data.data(), stride_in_bytes);
+
+  return true;
+}
+
+#ifdef IGL_STATIC_LIBRARY
+// Explicit template specialization
+// generated by autoexplicit.sh
+
+#endif

include/igl/png/writePNG.h

@@ -0,0 +1,41 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+//
+// Copyright (C) 2016 Daniele Panozzo <daniele.panozzo@gmail.com>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public License
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_PNG_WRITE_PNG_H
+#define IGL_PNG_WRITE_PNG_H
+#include "../igl_inline.h"
+#include <Eigen/Core>
+#include <string>
+
+namespace igl
+{
+  namespace png
+  {
+    // Writes an image to a png file
+    //
+    // Input:
+    //  R,G,B,A texture channels
+    // Output:
+    //  png_file  path to .png file
+    // Returns true on success, false on failure
+    //
+    IGL_INLINE bool writePNG
+    (
+      const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& R,
+      const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& G,
+      const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& B,
+      const Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic>& A,
+      const std::string png_file
+    );
+  }
+}
+
+#ifndef IGL_STATIC_LIBRARY
+#  include "writePNG.cpp"
+#endif
+
+#endif

index.html

@@ -214,6 +214,7 @@ few labs/companies/institutions using libigl:</p>
 
 <ul>
 <li><a href="http://www.adobe.com/technology/">Adobe Research</a></li>
+<li><a href="http://www.ea.com">Electronic Arts, Inc</a></li>
 <li><a href="http://meshconsultants.ca/">Mesh</a>, consultants, Canada</li>
 <li><a href="http://graphics.pixar.com/research/">Pixar Research</a></li>
 <li><a href="http://esotericsoftware.com/">Spine by Esoteric Software</a> is an animation tool dedicated to 2D characters.</li>
@@ -263,7 +264,7 @@ page</a>.</p>
 <h2 id="copyright">Copyright</h2>
 
 <p>2016 Alec Jacobson, Daniele Panozzo, Christian Schüller, Olga Diamanti, Qingnan
-Zhou, Nico Pietroni, Stefan Brugger, Kenshi Takayama, Wenzel Jakob, Nikolas De
+Zhou, Sebastian Koch, Nico Pietroni, Stefan Brugger, Kenshi Takayama, Wenzel Jakob, Nikolas De
 Giorgis, Luigi Rocca, Leonardo Sacht, Kevin Walliman, Olga Sorkine-Hornung, and others.</p>
 
 <p>Please see individual files for appropriate copyright notices.</p>

style-guidelines.html

@@ -185,8 +185,8 @@ Eigen::SparseMatrix<Atype> adjacency_matrix(const ... & F);
 <h2 id="templatingwitheigen">Templating with Eigen</h2>
 
 <p>Functions taking Eigen dense matrices/arrays as inputs and outputs (but <strong>not</strong>
-return arguments), should template on top of <code>Eigen::PlainObjectBase</code>. <strong>Each
-parameter</strong> should be derived using its own template.</p>
+return arguments), should template on top of <code>Eigen::PlainObjectBase</code>. **Each
+parameter** should be derived using its own template.</p>
 
 <p>For example,</p>
 
@@ -264,8 +264,8 @@ unnecessary prefaces. For example, instead of <code>compute_adjacency_matrix</co
 
 <h2 id="variablenamingconventions">Variable naming conventions</h2>
 
-<p>Libigl prefers short (even single character) variable names <em>with heavy
-documentation</em> in the comments in the header file or above the declaration of
+<p>Libigl prefers short (even single character) variable names _with heavy
+documentation_ in the comments in the header file or above the declaration of
 the function. When possible use <code>V</code> to mean a list of vertex positions and <code>F</code>
 to mean a list of faces/triangles.</p>
 

tutorial/107_ScreenCapture/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 2.8.12)
+project(107_ScreenCapture)
+
+add_executable(${PROJECT_NAME}_bin
+  main.cpp)
+target_include_directories(${PROJECT_NAME}_bin PRIVATE ${LIBIGL_INCLUDE_DIRS})
+target_compile_definitions(${PROJECT_NAME}_bin PRIVATE ${LIBIGL_DEFINITIONS})
+target_link_libraries(${PROJECT_NAME}_bin ${LIBIGL_LIBRARIES} ${LIBIGL_EXTRA_LIBRARIES})

tutorial/107_ScreenCapture/main.cpp

@@ -0,0 +1,82 @@
+#include <igl/readOFF.h>
+#include <igl/viewer/Viewer.h>
+#include <iostream>
+#include "tutorial_shared_path.h"
+#include <igl/png/writePNG.h>
+#include <igl/png/readPNG.h>
+
+// This function is called every time a keyboard button is pressed
+bool key_down(igl::viewer::Viewer& viewer, unsigned char key, int modifier)
+{
+  if (key == '1')
+  {
+    // Allocate temporary buffers
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> R(1280,800);
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> G(1280,800);
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> B(1280,800);
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> A(1280,800);
+
+    // Draw the scene in the buffers
+    viewer.core.draw_buffer(viewer.data,viewer.opengl,false,R,G,B,A);
+
+    // Save it to a PNG
+    igl::png::writePNG(R,G,B,A,"out.png");
+  }
+
+  if (key == '2')
+  {
+    // Allocate temporary buffers
+    Eigen::Matrix<unsigned char,Eigen::Dynamic,Eigen::Dynamic> R,G,B,A;
+
+    // Read the PNG
+    igl::png::readPNG("out.png",R,G,B,A);
+
+    // Replace the mesh with a triangulated square
+    Eigen::MatrixXd V(4,3);
+    V <<
+      -0.5,-0.5,0,
+       0.5,-0.5,0,
+       0.5, 0.5,0,
+      -0.5, 0.5,0;
+    Eigen::MatrixXi F(2,3);
+    F <<
+      0,1,2,
+      2,3,0;
+    Eigen::MatrixXd UV(4,2);
+    UV <<
+      0,0,
+      1,0,
+      1,1,
+      0,1;
+
+    viewer.data.clear();
+    viewer.data.set_mesh(V,F);
+    viewer.data.set_uv(UV);
+    viewer.core.align_camera_center(V);
+    viewer.core.show_texture = true;
+
+    // Use the image as a texture
+    viewer.data.set_texture(R,G,B);
+
+  }
+
+
+  return false;
+}
+
+int main(int argc, char *argv[])
+{
+  // Load a mesh in OFF format
+  Eigen::MatrixXd V;
+  Eigen::MatrixXi F;
+  igl::readOFF(TUTORIAL_SHARED_PATH "/bunny.off", V, F);
+
+  std::cerr << "Press 1 to render the scene and save it in a png." << std::endl;
+  std::cerr << "Press 2 to load the saved png and use it as a texture." << std::endl;
+
+  // Plot the mesh and register the callback
+  igl::viewer::Viewer viewer;
+  viewer.callback_key_down = &key_down;
+  viewer.data.set_mesh(V, F);
+  viewer.launch();
+}

tutorial/CMakeLists.txt

@@ -89,6 +89,9 @@ if(TUTORIALS_CHAPTER1)
   add_subdirectory("104_Colors")
   add_subdirectory("105_Overlays")
   add_subdirectory("106_ViewerMenu")
+  if(LIBIGL_WITH_PNG)
+    add_subdirectory("107_ScreenCapture")
+  endif()
 endif()
 
 # Chapter 2

tutorial/tutorial.html.REMOVED.git-id

@@ -1 +1 @@
-f46cce260ca12390184cb5fef8205ea121b3cb97
+0ba0c22d44c641478413576281dc8e745316e8c7

tutorial/tutorial.md.REMOVED.git-id

@@ -1 +1 @@
-f87bfabc63b2facf8ce8a778e86028722a7af22f
+6c7992b923fba06ca0986754535c23cb220875da