fix TextureDataPPMWriter skipping the last row of image data

src/ACGL/OpenGL/Data/TextureDataPPMWriter.cc

@@ -14,6 +14,12 @@ using namespace ACGL::Utils;
 
 bool ACGL::OpenGL::saveTextureDataToPPM(const ConstSharedTextureData& _textureData, const std::string& _filename)
 {
+    if(_textureData->getFormat() != GL_RGB)
+    {
+        error() << "saveTextureDataToPPM: Unsupported texture format, must be GL_RGB" << std::endl;
+        return false;
+    }
+
     std::ofstream outFileStream(_filename.c_str(), std::ios_base::out | std::ios_base::binary);
 
     if(!outFileStream.good())
@@ -36,7 +42,7 @@ bool ACGL::OpenGL::saveTextureDataToPPM(const ConstSharedTextureData& _textureDa
     }
     else
     {
-        error() << "saveTextureDataToPPM: Unsupported data format" << std::endl;
+        error() << "saveTextureDataToPPM: Unsupported texture type, must be GL_UNSIGNED_BYTE" << std::endl;
         return false;
     }
     outFileStream << maxValue;
@@ -45,15 +51,15 @@ bool ACGL::OpenGL::saveTextureDataToPPM(const ConstSharedTextureData& _textureDa
     outFileStream << "\n";
 
     // Now, write the image data in binary format
-    for(uint_t y = _textureData->getHeight()-1; y > 0; --y)
+    for(uint_t y = 0; y < _textureData->getHeight(); ++y)
     {
         for(uint_t x = 0; x < _textureData->getWidth(); ++x)
         {
-            uint_t i = (y * _textureData->getWidth()) + x;
+            uint_t i = ((_textureData->getHeight() - y - 1) * _textureData->getWidth()) + x;
 
-            outFileStream.put(_textureData->getData()[(4*i + 0) * getGLTypeSize(_textureData->getType())]);
-            outFileStream.put(_textureData->getData()[(4*i + 1) * getGLTypeSize(_textureData->getType())]);
-            outFileStream.put(_textureData->getData()[(4*i + 2) * getGLTypeSize(_textureData->getType())]);
+            outFileStream.put(_textureData->getData()[(3*i + 0) * getGLTypeSize(_textureData->getType())]);
+            outFileStream.put(_textureData->getData()[(3*i + 1) * getGLTypeSize(_textureData->getType())]);
+            outFileStream.put(_textureData->getData()[(3*i + 2) * getGLTypeSize(_textureData->getType())]);
         }
     }