RTM_triggered_copy_texture

C++ coding using Panda3D
1

hi, i try to port the python motion trail code into c++. my application crash without a regular error.
what im doing wrong?

//make a texture
	PT(GraphicsOutput) buffer;
	PT(Texture) bufferTEX;
	PT(Camera) backcam;
	buffer->add_render_texture(bufferTEX,GraphicsOutput::RTM_triggered_copy_texture);

	//create a new camera 

	backcam = new Camera("backcam");
	NodePath background= window->get_camera_group().attach_new_node(backcam);
	background.set_depth_test(0);
	background.set_depth_write(0);


	NodePath bcard = window->get_graphics_output()->get_texture_card();
	bcard.reparent_to(background);

	NodePath fcard = window->get_graphics_output()->get_texture_card();
	fcard.reparent_to(window->get_render_2d());
2 
   PT(GraphicsOutput) buffer;
    buffer->add_render_texture(bufferTEX,GraphicsOutput::RTM_triggered_copy_texture);

When you code in C++, you have to be more careful than when you use Python. In particular, you have to be careful about NULL and uninitialized pointers, things which generally aren’t possible in Python.

Here, you have declared the pointer “buffer”, but you haven’t initialized it to anything; then you try to call buffer->add_render_texture(), which is going to crash hard because buffer doesn’t point to a valid object.

David

3

cool, thank you!
yes i need to learn alot, i thought, i initialized it with PT(GraphicsOutput) buffer; at the same time.

4

cool now its working.

//make a texture
	PT(GraphicsOutput) buffer;
	PT(Texture) bufferTEX;
	PT(Camera) backcam;
	buffer = window->get_graphics_output()->make_texture_buffer("Buffer", 128, 128);
	buffer->add_render_texture(bufferTEX,GraphicsOutput::RTM_triggered_copy_texture);

	//create a new camera 

	backcam = new Camera("backcam");
	NodePath background= window->get_camera_group().attach_new_node(backcam);
	background.set_depth_test(0);
	background.set_depth_write(0);


	NodePath bcard = window->get_graphics_output()->get_texture_card();
	bcard.reparent_to(background);

	NodePath fcard = window->get_graphics_output()->get_texture_card();
	fcard.reparent_to(window->get_render_2d());