Fix video recording with SDL_Image

CMakeLists.txt

@@ -13,6 +13,11 @@ if(NOT EMSCRIPTEN)
     find_package(SDL2TTF REQUIRED)
 endif()
 
+find_package(SDL2Image)
+if(SDLIMAGE_FOUND)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D SDL2_IMAGE_ENABLED")
+endif()
+
 FILE(GLOB LibSources Lib/*.cpp Lib/*.h)
 add_library(library ${LibSources})
 
@@ -27,9 +32,9 @@ if(EMSCRIPTEN)
 
     configure_file(Tests/PhaseTransition.html PhaseTransition.html COPY_ONLY)
 else()
-    include_directories(${SDL2_INCLUDE_DIRS} ${SDL2TTF_INCLUDE_DIR} .)
+    include_directories(${SDL2_INCLUDE_DIRS} ${SDL2TTF_INCLUDE_DIR} ${SDL2_IMAGE_INCLUDE_DIR} .)
 
-    target_link_libraries(PhaseTransition library ${SDL2_LIBRARIES} ${SDL2TTF_LIBRARY} Threads::Threads)
+    target_link_libraries(PhaseTransition library ${SDL2_LIBRARIES} ${SDL2TTF_LIBRARY} ${SDL2_IMAGE_LIBRARY} Threads::Threads)
 endif()
 
 # Testing

Lib/Display.cpp

@@ -11,8 +11,8 @@
 #include "Display.h"
 #include "Globals.h"
 
-#if __cplusplus >= 201703L
-#include <filesystem>
+#ifdef SDL2_IMAGE_ENABLED
+#include <SDL_image.h>
 #endif
 
 CallbackHandler::CallbackHandler(int _totalParticleTypes):
@@ -143,9 +143,9 @@ void UniverseModifier::addNew(Universe &universe, const CallbackHandler &handler
 
 
 Display::Display(Universe &_universe, const std::string &_windowCaption, const std::string &_displayedCaption,
-        const std::string &_directoryPath, const std::string &recordingPath):
+        const std::string &_directoryPath, const std::string &_recordingPath):
     universe(_universe), displayedCaption(_displayedCaption), directoryPath(_directoryPath),
-        handler(_universe.getParticleTypes().size()) {
+        handler(_universe.getParticleTypes().size()), recordingPath(_recordingPath) {
     windowCaption = _windowCaption + " - " + _displayedCaption;
 
     if(SDL_Init(SDL_INIT_VIDEO) < 0) {
@@ -167,12 +167,14 @@ Display::Display(Universe &_universe, const std::string &_windowCaption, const s
     TTF_Init();
     font = TTF_OpenFont((directoryPath + "Fonts/DroidSans.ttf").c_str(), 24);
 
+    isRecording = false;
     if(! recordingPath.empty()) {
-#if __cplusplus >= 201703L
-        auto path = std::filesystem::path(recordingPath);
-        std::filesystem::create_directories(path.parent_path());
+#if SDL2_IMAGE_ENABLED
+        isRecording = true;
+        system((std::string("mkdir -p ") + recordingPath).c_str());
+#else
+        std::cerr << "Warning: trying to record, but this build does not support recording" << std::endl;
 #endif
-        //recorder.open(recordingPath, CV_FOURCC('M','J','P','G'), 60, cv::Size(universe.getConfig().sizeX, universe.getConfig().sizeY));
     }
 }
 
@@ -187,22 +189,12 @@ Display::~Display() {
 }
 
 const CallbackHandler & Display::update() {
-    /*
-    if(recorder.isOpened()) {
-        recorder.write(img);
-
-        auto now = std::chrono::system_clock::now();
-        auto millisFromEpoch = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
-        if(millisFromEpoch % 1000 < 500)
-            drawText(img, "Recording...", cv::Point(30, 30));
-    }
-    */
-
     SDL_FillRect(surface, nullptr, 0x000000);
     drawParticles();
     drawDisplayedCaption();
     drawStats();
     drawPointer();
+    if(isRecording) recordAndDrawRecordingText();
     SDL_UpdateWindowSurface(window);
     SDL_Event event;
     while(SDL_PollEvent(& event)) {
@@ -310,6 +302,19 @@ void Display::drawParticles() {
     }
 }
 
+void Display::recordAndDrawRecordingText() {
+    if(! isRecording) return;
+
+#ifdef SDL2_IMAGE_ENABLED
+    IMG_SaveJPG(surface, (recordingPath + std::to_string(timestamp++) + ".jpg").c_str(), 95);
+#endif
+
+    auto now = std::chrono::system_clock::now();
+    auto millisFromEpoch = std::chrono::duration_cast<std::chrono::milliseconds>(now.time_since_epoch()).count();
+    if (millisFromEpoch % 1000 < 500)
+        drawText("Recording...", 30, 30);
+}
+
 void Display::drawSpriteFromCenter(SDL_Surface *sprite, int x, int y) {
     assert(sprite != nullptr);
     SDL_Rect inputRect{0, 0, sprite->w, sprite->h};

Lib/Display.h

@@ -48,17 +48,22 @@ class Display {
     void drawStats();
     void drawText(const std::string &text, int x, int y);
     void drawSpriteFromCenter(SDL_Surface *sprite, int x, int y);
+    void recordAndDrawRecordingText();
     std::tuple<int, double, double> computeStats() const;
 
     Universe &universe;
     std::string windowCaption, displayedCaption;
     std::string directoryPath;
     CallbackHandler handler;
-    //cv::VideoWriter recorder;
     SDL_Window *window = nullptr;
     SDL_Surface *surface = nullptr;
     SDL_Surface *defaultPointer = nullptr, *increasePointer = nullptr, *decreasePointer = nullptr;
     TTF_Font *font;
+
+    std::string recordingPath;
+    bool isRecording;
+
+    int timestamp = 0;
 };
 
 std::string to_string(double x, int precision);

PhaseTransition/PhaseTransition.cpp

@@ -32,7 +32,7 @@ int main(int argc, char **argv) {
 #endif
 
 	std::string recordingPath;
-	if(! globalSetup->recordingPrefix.empty()) recordingPath = globalSetup->recordingPrefix + currentDateTime() + ".avi";
+	if(! globalSetup->recordingPrefix.empty()) recordingPath = globalSetup->recordingPrefix + currentDateTime() + "/";
 	globalUniverse.reset(new Universe({ globalSetup->sizeX, globalSetup->sizeY, globalSetup->forceFactor, globalSetup->gravity },
 	        globalSetup->particleTypes));
 	globalSetup->addParticlesToUniverse(*globalUniverse);

README.md

@@ -12,8 +12,9 @@ Requirements:
 * cmake 3.10+
 * pthreads
 * SDL 2 and SDL_ttf 2
-* gtest (optional)
-* emscripten (optional)
+* SDL_image 2 (optional - recording video)
+* gtest (optional - running tests)
+* emscripten (optional - building for web)
 
 Building:
 

cmake/FindSDL2Image.cmake

@@ -0,0 +1,100 @@
+# Locate SDL_image library
+#
+# This module defines:
+#
+# ::
+#
+#   SDL2_IMAGE_LIBRARIES, the name of the library to link against
+#   SDL2_IMAGE_INCLUDE_DIRS, where to find the headers
+#   SDL2_IMAGE_FOUND, if false, do not try to link against
+#   SDL2_IMAGE_VERSION_STRING - human-readable string containing the version of SDL_image
+#
+#
+#
+# For backward compatibility the following variables are also set:
+#
+# ::
+#
+#   SDLIMAGE_LIBRARY (same value as SDL2_IMAGE_LIBRARIES)
+#   SDLIMAGE_INCLUDE_DIR (same value as SDL2_IMAGE_INCLUDE_DIRS)
+#   SDLIMAGE_FOUND (same value as SDL2_IMAGE_FOUND)
+#
+#
+#
+# $SDLDIR is an environment variable that would correspond to the
+# ./configure --prefix=$SDLDIR used in building SDL.
+#
+# Created by Eric Wing.  This was influenced by the FindSDL.cmake
+# module, but with modifications to recognize OS X frameworks and
+# additional Unix paths (FreeBSD, etc).
+
+#=============================================================================
+# Copyright 2005-2009 Kitware, Inc.
+# Copyright 2012 Benjamin Eikel
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+find_path(SDL2_IMAGE_INCLUDE_DIR SDL_image.h
+        HINTS
+        ENV SDL2IMAGEDIR
+        ENV SDL2DIR
+        PATH_SUFFIXES SDL2
+        # path suffixes to search inside ENV{SDLDIR}
+        include/SDL2 include
+        PATHS ${SDL2_IMAGE_PATH}
+        )
+
+if(CMAKE_SIZEOF_VOID_P EQUAL 8)
+    set(VC_LIB_PATH_SUFFIX lib/x64)
+else()
+    set(VC_LIB_PATH_SUFFIX lib/x86)
+endif()
+
+find_library(SDL2_IMAGE_LIBRARY
+        NAMES SDL2_image
+        HINTS
+        ENV SDL2IMAGEDIR
+        ENV SDL2DIR
+        PATH_SUFFIXES lib ${VC_LIB_PATH_SUFFIX}
+        PATHS ${SDL2_IMAGE_PATH}
+        )
+
+if(SDL2_IMAGE_INCLUDE_DIR AND EXISTS "${SDL2_IMAGE_INCLUDE_DIR}/SDL_image.h")
+    file(STRINGS "${SDL2_IMAGE_INCLUDE_DIR}/SDL_image.h" SDL2_IMAGE_VERSION_MAJOR_LINE REGEX "^#define[ \t]+SDL_IMAGE_MAJOR_VERSION[ \t]+[0-9]+$")
+    file(STRINGS "${SDL2_IMAGE_INCLUDE_DIR}/SDL_image.h" SDL2_IMAGE_VERSION_MINOR_LINE REGEX "^#define[ \t]+SDL_IMAGE_MINOR_VERSION[ \t]+[0-9]+$")
+    file(STRINGS "${SDL2_IMAGE_INCLUDE_DIR}/SDL_image.h" SDL2_IMAGE_VERSION_PATCH_LINE REGEX "^#define[ \t]+SDL_IMAGE_PATCHLEVEL[ \t]+[0-9]+$")
+    string(REGEX REPLACE "^#define[ \t]+SDL_IMAGE_MAJOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_IMAGE_VERSION_MAJOR "${SDL2_IMAGE_VERSION_MAJOR_LINE}")
+    string(REGEX REPLACE "^#define[ \t]+SDL_IMAGE_MINOR_VERSION[ \t]+([0-9]+)$" "\\1" SDL2_IMAGE_VERSION_MINOR "${SDL2_IMAGE_VERSION_MINOR_LINE}")
+    string(REGEX REPLACE "^#define[ \t]+SDL_IMAGE_PATCHLEVEL[ \t]+([0-9]+)$" "\\1" SDL2_IMAGE_VERSION_PATCH "${SDL2_IMAGE_VERSION_PATCH_LINE}")
+    set(SDL2_IMAGE_VERSION_STRING ${SDL2_IMAGE_VERSION_MAJOR}.${SDL2_IMAGE_VERSION_MINOR}.${SDL2_IMAGE_VERSION_PATCH})
+    unset(SDL2_IMAGE_VERSION_MAJOR_LINE)
+    unset(SDL2_IMAGE_VERSION_MINOR_LINE)
+    unset(SDL2_IMAGE_VERSION_PATCH_LINE)
+    unset(SDL2_IMAGE_VERSION_MAJOR)
+    unset(SDL2_IMAGE_VERSION_MINOR)
+    unset(SDL2_IMAGE_VERSION_PATCH)
+endif()
+
+set(SDL2_IMAGE_LIBRARIES ${SDL2_IMAGE_LIBRARY})
+set(SDL2_IMAGE_INCLUDE_DIRS ${SDL2_IMAGE_INCLUDE_DIR})
+
+include(FindPackageHandleStandardArgs)
+
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(SDL2_image
+        REQUIRED_VARS SDL2_IMAGE_LIBRARIES SDL2_IMAGE_INCLUDE_DIRS
+        VERSION_VAR SDL2_IMAGE_VERSION_STRING)
+
+# for backward compatibility
+set(SDLIMAGE_LIBRARY ${SDL2_IMAGE_LIBRARIES})
+set(SDLIMAGE_INCLUDE_DIR ${SDL2_IMAGE_INCLUDE_DIRS})
+set(SDLIMAGE_FOUND ${SDL2_IMAGE_FOUND})
+
+mark_as_advanced(SDL2_IMAGE_LIBRARY SDL2_IMAGE_INCLUDE_DIR)