[WB, RTG, Window] Rendering graphics to wb public window

[mateusz_s]

Hi,
I am adapting my Raycaster project to display its output in different modes.
So far I am finished with Fullscreen RTG and HAM8 modes.

I also want the option to show the output on public WB window (when the WB is in RTG mode). And I got couple of issues. Maybe you can help me a bit.

Issue no #1
So to copy my output frame buffer to wb public window I am using:

WritePixelArray(output_buffer_32, 0, 0, bytes_per_row, FRM_window->RPort, 0, 0, output_width, output_height, output_pixel_format );

The result is OK like below:



So basically everythying is working OK. But this is just a single buffer rendering, so I have the screen tearing inside the game.
I am not sure how to make double or triple buffer. Because when using WritePixelArray(..) I am blitting to the Window Rastport.
In my other cases (fullscreen 32bit and ham8) I was switching the screen bitmaps.

How can I add second or third buffer? And how can I have synced blitting using two buffers. In previurs modes I was using RethinkDisplay() for double buffering with success. I am not sure what to do in this case - I mean I got only public window without the screen.


Issue no #2
How can I protect the cursor not to leave my window?
I can move mouse free to move the view, but if the cursor will be outside my window,
and I press "left-button" I will lost the focus from my window and I will "back" to workbench.


I am attaching part of my code.

- Creating Public WB Window -

UBYTE FRM_Init_WB_Window()
{
    // Get the size of WB screen to set the new window in the middle of the screen.
    ULONG win_x_pos = 10, win_y_pos = 10;

    struct Screen* pubscreen = LockPubScreen(NULL); 
    if (pubscreen != NULL)
    {
        win_x_pos = (pubscreen->Width - FRM_requested_width) / 2;
        win_y_pos = (pubscreen->Height - FRM_requested_height) / 2;
        UnlockPubScreen(NULL, pubscreen);
    }

    FRM_Console_Write("\nOpening window: ");

	// Create full screen window on screen.
	FRM_window = OpenWindowTags(        NULL,
										WA_Left, win_x_pos,
										WA_Top, win_y_pos,
										WA_InnerWidth, FRM_requested_width,
										WA_InnerHeight, FRM_requested_height,
                                        WA_ScreenTitle, (ULONG)FRM_WINDOW_NAME,
                                        WA_WindowName, (ULONG)FRM_WINDOW_NAME,
	                                    WA_RMBTrap, TRUE,
	                                    WA_Activate, FALSE,
	                                    WA_CloseGadget, TRUE,
	                                    WA_DepthGadget, TRUE,
	                                    WA_DragBar, TRUE,
	                                    WA_SizeGadget, FALSE,
	                                    WA_SizeBBottom, FALSE,
                                        WA_ReportMouse, TRUE,
	                                    WA_GimmeZeroZero, TRUE, 
                                        WA_Hidden, TRUE,
										WA_IDCMP, IDCMP_RAWKEY | IDCMP_DELTAMOVE | IDCMP_MOUSEMOVE | IDCMP_MOUSEBUTTONS | IDCMP_CLOSEWINDOW,
										TAG_END); 

    if (!FRM_window) 
    {
        FRM_Console_Write("[FAILED]");
        return 0;
	}

    FRM_Console_Write("[OK]");

    // Get window signal mask.
    FRM_window_user_port = CreateMsgPort();
    FRM_window->UserPort = FRM_window_user_port;

 	FRM_window_signal = ( 1 << FRM_window->UserPort->mp_SigBit );    
    FRM_window_rastport = FRM_window->RPort;

    return 1;
}

- Main Message Loop code -

void FRM_Run_Window_32bit_Single_Buffer(void)
{
    // for FPS counter
	int fps = 0;
    LONG frames = 0;
    LONG elapsed_time = 0;
    LONG curr_time = clock();
    LONG start_time = curr_time;
    char fps_string[24];

    // Signal mask for window.
    ULONG signal_mask = ( 1 << FRM_window_user_port->mp_SigBit );

    // Enter main loop.
    BYTE FRM_main_loop = 1;

	// get bytes per row for window mode
	u_int32 bytes_per_row = FRM_requested_width * (FRM_requested_bits_per_pixel / 8);

    while (FRM_main_loop)
    {
        IO_input.mouse_dx = 0;
		IO_input.mouse_dy = 0;

        // Enter Window Message Loop - handle messages and events.
	    if(SetSignal(0L, signal_mask) & signal_mask)
	    {
		    struct IntuiMessage	*imsg;

            while( imsg = (struct IntuiMessage *)GetMsg(FRM_window_user_port) )
            {
                switch (imsg->Class)
                {
                    case IDCMP_MOUSEMOVE:
                        IO_input.mouse_dx = imsg->MouseX;
		                IO_input.mouse_dy = imsg->MouseY;
                    break;

                    case IDCMP_RAWKEY:
                        if (imsg->Code & 0x80)
                        {                
                            IO_input.keys[ (u_int8)(imsg->Code & 0x7F) ] = 0;
                        }
                        else
                        {
                            IO_input.keys[ (u_int8)(imsg->Code & 0x7F) ] = 1;
                        }
                    break;
                }
                ReplyMsg((struct Message *)imsg);
            }       
	    }  

        // -- Single Buffering routine --

                // --- DRAW HERE ---

                    // get fps
                    frames++;
                    curr_time = clock();
                    int32 TM_time_total = (curr_time - start_time) / CLOCKS_PER_SEC;

                    if (TM_time_total - elapsed_time >= 1)
                    {
                        fps = frames;

                        // reset
                        frames = 0;
                        elapsed_time += 1;
                    }

                    EN_Run(&FRM_main_loop);   

                    WritePixelArray(IO_prefs.output_buffer_32, 0, 0, bytes_per_row, FRM_window->RPort, 0, 0, FRM_requested_width, FRM_requested_height, 1 );

                    // Display FPS info.
                    memset(&fps_string, 0, 24);
                    sprintf(fps_string, "%d  %.3f", fps, IO_prefs.delta_time);

                    Move(FRM_window_rastport, 0,8);
                    Text(FRM_window_rastport, (CONST_STRPTR)fps_string, strlen(fps_string));

                // -----------------

        // -- End Single Buffering routine
    }
}

HUUUgeee thanks from advance!

[Thomas Richter]

Originally Posted by mateusz_s

Issue no #1
So to copy my output frame buffer to wb public window I am using:

WritePixelArray(output_buffer_32, 0, 0, bytes_per_row, FRM_window->RPort, 0, 0, output_width, output_height, output_pixel_format );

I am not sure how to make double or triple buffer. Because when using WritePixelArray(..) I am blitting to the Window Rastport.

That does not "blit" anything. It uses the CPU to copy data, on native screens even a chunky to planar conversion is involved. The problem is that the source array is either not in a mode the native Amiga graphics support, or is not on board of the graphics card to use a VGA accelerator for the conversion.


If you want to render directly to a graphics card, you need to use the P96 API in one way or another, such as allocating a bitmap on the board, then lock the bitmap, render into it, then copy it to the target. That would then use the native blitter (if there is one).

Originally Posted by mateusz_s

How can I add second or third buffer? And how can I have synced blitting using two buffers. In previurs modes I was using RethinkDisplay() for double buffering with success. I am not sure what to do in this case - I mean I got only public window without the screen.

The workbench screen has obviously only a single screen frame buffer, so there is no double buffering. If you want double buffering, you need to open a screen on your own, and use the intuition API for double buffering. There is example code in the RKRMs how to do that.

Originally Posted by mateusz_s

Issue no #2
How can I protect the cursor not to leave my window?

You don't. This is very intrusive, and very unfriendly to the user. If you want to have a "display of your own", the right abstraction is a screen, not a window.

Originally Posted by mateusz_s

I can move mouse free to move the view, but if the cursor will be outside my window,

and I press "left-button" I will lost the focus from my window and I will "back" to workbench.

That is exactly what windows are meant for, namely that users can leave them *at their own will*, and can redirect the input focus to another window if they feel like.