-Once in a while .... (set_event_filter) +Providing direct memory access to SDL_Surface's pixels
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-So I have been hacking for a while on SDL::Events::set_event_filter. The code below is an example usage. The magic behind this is here
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In an attempt to make pixel access easier on SDL_Surface pixels. I have started work on SDLx::Surface. So far I have only start on the 32 bpp surfaces.
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The general idea is to make Pointer Values (PV) of each pixel in the surface and place them into a 2D matrix. First I make pointer values like this:
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SV * get_pixel32 (SDL_Surface *surface, int x, int y) +{ + //Convert the pixels to 32 bit + Uint32 *pixels = (Uint32 *)surface->pixels; + + //Get the requested pixel + Uint32* u_ptr = pixels + ( y * surface->w ) + x ; + + SV* sv = newSVpv("a",1); //Make a temp SV* value on the go + SvCUR_set(sv, sizeof(Uint32)); //Specify the new CUR length + SvLEN_set(sv, sizeof(Uint32)); //Specify the LEN length + SvPV_set(sv,(char*)u_ptr); // set the actual pixel's pointer as the memory space to use + + return sv; //make a modifiable reference using u_ptr's place as the memory :) + +} +
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Next I loop through all the pixels and put them in a 2D array format, shown below:
AV * construct_p_matrix ( SDL_Surface *surface ) +{ + AV * matrix = newAV(); + int i, j; + for( i =0 ; i < surface->w; i++) + { + AV * matrix_row = newAV(); + for( j =0 ; j < surface->h; j++) + { + av_push(matrix_row, get_pixel32(surface, i,j) ); + } + av_push(matrix, newRV_noinc((SV*) matrix_row) ); + } + + return matrix; +} +
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You can see the complete here.
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In Perl I can do a get access on this pixel using:
-So I have been hacking for a while on SDL::Events::set_event_filter. The code below is an example usage. The magic behind this is here
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1 #!/usr/bin/perl -w - 2 use strict; - 3 use warnings; - 4 use SDL v2.3; #Require the redesign branch - 5 use SDL::Video; - 6 use SDL::Event; - 7 use SDL::Events; - 8 - 9 SDL::init(SDL_INIT_VIDEO); -10 my $display = SDL::Video::set_video_mode(640,480,32, SDL_SWSURFACE ); -11 my $event = SDL::Event->new(); -12 -13 #This filters out all ActiveEvents -14 my $filter = sub { -15 my ($e, $type) = ($_[0], $_[0]->type); -16 if($type == SDL_ACTIVEEVENT){ return 0 } -17 elsif($type == SDL_MOUSEBUTTONDOWN && $e->button_button == 1){ return 0 } -18 else { return 1; } -19 }; -20 -21 SDL::Events::set_event_filter($filter); -22 -23 while(1) -24 { -25 -26 SDL::Events::pump_events(); -27 if(SDL::Events::poll_event($event)) -28 { -29 -30 if( $event->type == SDL_ACTIVEEVENT) -31 { -32 print "Hello Mouse!!!\n" if ($event->active_gain && ($event->active_state == SDL_APPMOUSEFOCUS) ); -33 print "Bye Mouse!!!\n" if (!$event->active_gain && ($event->active_state == SDL_APPMOUSEFOCUS) ); -34 } -35 if( $event->type == SDL_MOUSEBUTTONDOWN) -36 { -37 my ($x, $y, $but ) = ($event->button_x, $event->button_y, $event->button_button); -38 warn "$but CLICK!!! at $x and $y \n"; -39 } -40 -41 last if($event->type == SDL_QUIT); -42 } -43 } -44 SDL::quit();
Tinker with $filter and look at perldoc lib/SDL/pods/Event.pod.
Have fun,
--yapgh
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