Image noise: Difference between revisions

=={{header|Perl 6}}==

We'll use minimal mappings for SDL2. The resulting code is embarrassingly slow, but it's better than nothing.

<lang perl6>use NativeCall;

class SDL_Window is repr('CStruct') {}

class SDL_Renderer is repr('CStruct') {}

my ($w, $h) = 320, 240;

my SDL_Window $window;

my SDL_Renderer $renderer;

constant $sdl-lib = 'libSDL2';

constant SDL_INIT_TIMER = 0x00000001;

constant SDL_INIT_VIDEO = 0x00000020;

constant SDL_WINDOWPOS_UNDEFINED_MASK = 0x1FFF0000;

constant SDL_WINDOW_SHOWN = 0x00000004;

sub SDL_Init(int32 $flag) returns int32 is native($sdl-lib) {*}

sub SDL_Quit() is native($sdl-lib) {*}

sub SDL_CreateWindow(Str $title, int $x, int $y, int $w, int $h, int32 $flag) returns SDL_Window is native($sdl-lib) {*}

sub SDL_CreateRenderer(SDL_Window $, int $, int $) returns SDL_Renderer is native($sdl-lib) {*}

sub SDL_SetRenderDrawColor(SDL_Renderer $, int $r, int $g, int $b, int $a) returns Int is native($sdl-lib) {*}

sub SDL_RenderClear(SDL_Renderer $) returns Int is native($sdl-lib) {*}

sub SDL_RenderDrawPoint( SDL_Renderer $, int $x, int $y ) returns Int is native($sdl-lib) {*}

sub SDL_RenderPresent(SDL_Renderer $) is native($sdl-lib) {*}

sub render {

SDL_SetRenderDrawColor($renderer, 0, 0, 0, 0);

SDL_RenderClear($renderer);

SDL_SetRenderDrawColor($renderer, 255, 255, 255, 0);

for ^$w X ^$h -> $i, $j {

SDL_RenderDrawPoint( $renderer, $i, $j ) if rand < .5;

}

SDL_RenderPresent($renderer);

}

SDL_Init(SDL_INIT_VIDEO);

$window = SDL_CreateWindow(

"some white noise",

SDL_WINDOWPOS_UNDEFINED_MASK, SDL_WINDOWPOS_UNDEFINED_MASK,

$w, $h,

SDL_WINDOW_SHOWN

);

$renderer = SDL_CreateRenderer( $window, -1, 1 );

for ^10 {

my $then = now;

render();

note "{1 / (now - $then)} fps";

}

END { SDL_Quit() }</lang>