4 files changed, 35 insertions, 9 deletions

diff --git a/src/OffscreenContext.h b/src/OffscreenContext.h
index 8645da7..a1792b4 100644
--- a/src/OffscreenContext.h
+++ b/src/OffscreenContext.h
@@ -8,6 +8,7 @@ struct OffscreenContext *create_offscreen_context(int w, int h);
 void bind_offscreen_context(OffscreenContext *ctx);
 bool teardown_offscreen_context(OffscreenContext *ctx);
 bool save_framebuffer(OffscreenContext *ctx, const char *filename);
+bool save_framebuffer(OffscreenContext *ctx, std::ostream &output);
 std::string offscreen_context_getinfo(OffscreenContext *ctx);
 
 #endif
diff --git a/src/OffscreenContextGLX.cc b/src/OffscreenContextGLX.cc
index e607593..73794cc 100644
--- a/src/OffscreenContextGLX.cc
+++ b/src/OffscreenContextGLX.cc
@@ -45,6 +45,7 @@ See Also
 #include <GL/glx.h>
 
 #include <assert.h>
+#include <fstream>
 #include <sstream>
 
 #include <sys/utsname.h> // for uname
@@ -300,8 +301,24 @@ bool teardown_offscreen_context(OffscreenContext *ctx)
 */
 bool save_framebuffer(OffscreenContext *ctx, const char *filename)
 {
+	std::ofstream fstream(filename);
+	if (!fstream.is_open()) {
+		PRINTB("Can't open file \"%s\" for writing", filename);
+		return false;
+	} else {
+		save_framebuffer(ctx, fstream);
+		fstream.close();
+	}
+	return true;
+}
+
+/*!
+  Capture framebuffer from OpenGL and write it to the given ostream
+*/
+bool save_framebuffer(OffscreenContext *ctx, std::ostream &output)
+{
   glXSwapBuffers(ctx->xdisplay, ctx->xwindow);
-  if (!ctx || !filename) return false;
+  if (!ctx) return false;
   int samplesPerPixel = 4; // R, G, B and A
   GLubyte pixels[ctx->width * ctx->height * samplesPerPixel];
   glReadPixels(0, 0, ctx->width, ctx->height, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
@@ -315,7 +332,7 @@ bool save_framebuffer(OffscreenContext *ctx, const char *filename)
   }
   flip_image(pixels, flippedBuffer, samplesPerPixel, ctx->width, ctx->height);
 
-  bool writeok = write_png(filename, flippedBuffer, ctx->width, ctx->height);
+  bool writeok = write_png(output, flippedBuffer, ctx->width, ctx->height);
 
   free(flippedBuffer);
 
diff --git a/src/imageutils-lodepng.cc b/src/imageutils-lodepng.cc
index 96d9d90..fab1cd9 100644
--- a/src/imageutils-lodepng.cc
+++ b/src/imageutils-lodepng.cc
@@ -9,8 +9,16 @@ bool write_png(std::ostream &output, unsigned char *pixels, int width, int heigh
   //LodePNG_Text_add(&encoder.infoPng.text, "Comment", "Created with LodePNG");
   size_t dataout_size = -1;
   unsigned char *dataout = (unsigned char *)malloc(width*height*4);
+	if (!dataout) {
+		perror("Error allocating memory while writing png\n");
+		return false;
+	}
   LodePNG_encode(&dataout, &dataout_size, pixels, width, height, LCT_RGBA, 8);
-	output.write( reinterpret_cast<const char*>(dataout), dataout_size );;
+	try {
+		output.write( reinterpret_cast<const char*>(dataout), dataout_size );
+	} catch (const std::ios_base::failure &e) {
+    std::cerr << "Error writing to ostream:" << e.what() << "\n";
+	}
 	free( dataout );
   return true;
 }
diff --git a/src/imageutils-macosx.cc b/src/imageutils-macosx.cc
index fc4803b..5236b76 100644
--- a/src/imageutils-macosx.cc
+++ b/src/imageutils-macosx.cc
@@ -11,12 +11,12 @@ size_t write_bytes_to_ostream (void *info,const void *buffer,size_t count)
 	size_t startpos = output->tellp();
 	size_t endpos = startpos;
 	try {
-		output->write( reinterpret_cast<const char *>buffer, count );
+		output->write( (const char *)buffer, count );
 		endpos = output->tellp();
 	} catch (const std::ios_base::failure& e)
-    std::cerr << "Error writing to ostream:" << e.what() << "\n";
+		std::cerr << "Error writing to ostream:" << e.what() << "\n";
 	}
-	return endpos-startpos;
+	return (endpos-startpos);
 }
 
 CGDataConsumerRef dataconsumer CGDataConsumerCreateWithOstream(std::ostream &output)
@@ -48,8 +48,8 @@ bool write_png(std::ostream &output, unsigned char *pixels, int width, int heigh
     return false;
   }
 
-	CGDataConsumerRef dataconsumer = CGDataConsumerCreateWithOstream(output);
-	/*
+  CGDataConsumerRef dataconsumer = CGDataConsumerCreateWithOstream(output);
+  /*
   CFStringRef fname = CFStringCreateWithCString(kCFAllocatorDefault, filename, kCFStringEncodingUTF8);
   CFURLRef fileURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
                                                   fname, kCFURLPOSIXPathStyle, false);
@@ -59,7 +59,7 @@ bool write_png(std::ostream &output, unsigned char *pixels, int width, int heigh
   }
 
 	CGDataConsumerRef dataconsumer = CGDataConsumerCreateWithURL(fileURL);
-	*/
+  */
 
   CFIndex                 fileImageIndex = 1;
   CFMutableDictionaryRef  fileDict       = NULL;