X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=pages%2Fblog-0006.html-inc;h=2e202e79e222745e30148733ba74569908ecbd32;hb=c8ad4fe9f211e727310a1ce6d23ffb1d7822d71f;hp=83a05ba23c0e352fd270773c2f64bbc88ba2ff59;hpb=d502f71f4cb7e6073e2629cdba69f20e7001b721;p=sdlgit%2FSDL-Site.git diff --git a/pages/blog-0006.html-inc b/pages/blog-0006.html-inc index 83a05ba..2e202e7 100644 --- a/pages/blog-0006.html-inc +++ b/pages/blog-0006.html-inc @@ -1,6 +1,81 @@
#!/usr/bin/env perl
use SDL;
use SDL::Events;
use SDL::Event;
use SDL::Video;
SDL::init(SDL_INIT_VIDEO);
my $display = SDL::Video::set_video_mode(640,480,32, SDL_SWSURFACE );
my $event = SDL::Event->new();
while(1)
{
SDL::Events::pump_events();
if(SDL::Events::poll_event($event) && $event->type == SDL_ACTIVEEVENT)
{
print "Hello Mouse!!!\n" if ($event->active_gain && ($event->active_state == SDL_APPMOUSEFOCUS) );
print "Bye Mouse!!!\n" if (!$event->active_gain && ($event->active_state == SDL_APPMOUSEFOCUS) );
}
exit if($event->type == SDL_QUIT);
}
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.
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:
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 :) + +} +
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; +} +
You can see the complete here.
In Perl I can do a get access on this pixel using:
my $surf32_matrix = SDLx::Surface::pixel_array($screen_surface); + print unpack 'b*', $surf32_matrix->[0][0]; # pixel value at x = 0 and y =0 +#OUTPUT: +# 11111111000000000000000000000000 +
The structure of the PV is using Devel::Peek is :
print Dump $surf32_matrix->[0][0]; +#OUTPUT: +#SV = PV(0xed0dbc) at 0xeb5344 +# REFCNT = 1 +# FLAGS = (POK,pPOK) +# PV = 0x9e04ac "\0\0\377\0" +# CUR = 4 +# LEN = 4 +
The problem is in setting the value of this pointer value. I have tried the following things with no success:
if ( SDL::Video::MUSTLOCK($screen_surface) ) { + return if ( SDL::Video::lock_surface($screen_surface) < 0 ); #required for pixel operations +} + +#USING pack + +my $green = pack 'b*', '11111111000000000000000000000000'; +substr( $surf32_matrix->[0][0], 0, 8 * 4, $green); #no change +#substr( $surf32_matrix->[0][0], 0, 8 * 4, 0xFF000000); segfault +substr( ${$surf32_matrix->[0][0]}, 0, 8 * 4, 0xFF000000); #no change +#$surf32_matrix->[0][0] = $green; SEGFAULT's cannot write to memory +${$surf32_matrix->[0][0]} = $green; #no change + + +SDL::Video::unlock_surface($screen_surface) + if ( SDL::Video::MUSTLOCK($screen_surface) ); +
You can see an example here.
Any help will be greatly appreciated.
+ \ No newline at end of file