(C++) QImageExample3

 

Technical facts

 

Application type(s)

• Desktop application

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• GUI application

C++ standard:

• C++11

Compiler(s):

• G++ 4.9.2

Libraries used:

• Qt: version 5.4.1 (32 bit)
• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppQImageExample3/CppQImageExample3.pro

 

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win32 {   # Windows only   message("Console application, built for Windows")   QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++ } macx {   # Mac only   message("Console application, built for Mac")   QMAKE_CXXFLAGS = -mmacosx-version-min=10.7 -std=gnu0x -stdlib=libc+   CONFIG +=c++11 } unix:!macx{   # Linux only   message("Console application, built for Linux")   QMAKE_CXXFLAGS += -Werror   QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++ } cross_compile {   # Crosscompile only   message("Console application, cross-compiling from Linux to Windows")   QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++ } # Go ahead and use Qt.Core: it is about as platform-independent as # the STL and Boost QT += core # Go ahead and use Qt.Gui: it is about as platform-independent as # the STL and Boost. It is needed for QImage QT += gui # Don't define widgets: it would defy the purpose of this console # application to work non-GUI #greaterThan(QT_MAJOR_VERSION, 4): QT += widgets CONFIG   += console CONFIG   -= app_bundle TEMPLATE = app # # # Type of compile # # CONFIG(release, debug|release) {   DEFINES += NDEBUG NTRACE_BILDERBIKKEL } SOURCES += main.cpp

 

 

 

 

 

./CppQImageExample3/main.cpp

 

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#include <cassert> #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Weffc++" #pragma GCC diagnostic ignored "-Wunused-local-typedefs" #pragma GCC diagnostic ignored "-Wunused-but-set-parameter" #include <QImage> #pragma GCC diagnostic pop QImage CreateImage(const int width, const int height, const int z) noexcept {   QImage image(width,height,QImage::Format_ARGB32);   for (int y=0;y!=height;++y)   {     for (int x=0;x!=width;++x)     {       image.setPixel(         x,y,         qRgb((x+z+0)%256,(y+z+0)%256,(x+y+z)%256) //Color       );     }   }   return image; } void DrawImage(   QImage& target, const QImage& source,   const int left, const int top ) noexcept {   const int width = source.width();   const int height = source.height();   for (int y=0; y!=height; ++y)   {     for (int x=0; x!=width; ++x)     {       target.setPixel(left+x,top+y,source.pixel(x,y));     }   } } QImage DrawTiled(   const int n_cols, const int n_rows,   const QImage& a, const QImage& b ) noexcept {   assert(a.width()  == b.width());   assert(a.height() == b.height());   const int block_width  = a.width();   const int block_height = a.height();   const int width  = n_rows * block_width;   const int height = n_cols * block_height;   QImage result(width,height,QImage::Format_ARGB32);   for (int y=0; y!=n_rows; ++y)   {     for (int x=0; x!=n_cols; ++x)     {       DrawImage(         result,         (std::rand() >> 4) % 2 ? a : b,         block_width * x,         block_width * y       );     }   }   return result; } int main() {   const QImage a = CreateImage(64,64,0);   const QImage b = CreateImage(64,64,128);   const QImage c = DrawTiled(4,4,a,b);   c.save("CppQImageExample3.png"); }