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@rootext rootext/app.dart
Created May 21, 2019

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Dart + SDL2 crash example
import 'dart:ffi';
import 'dart:convert';
void main() {
var sdl = DynamicLibrary.open('SDL2.dll');
loadSDL(sdl);
sdlInit(SDL_INIT_VIDEO);
var title = CString.fromUtf8('Dart FFI + SDL');
var window = sdlCreateWindow(title, 100, 100, 600, 400, SDL_WINDOW_RESIZABLE | SDL_WINDOW_OPENGL);
var renderer = sdlCreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
sdlSetRenderDrawColor(renderer, 0, 179, 252, 0);
var event = SDL_Event(0);
var exit = false;
while (!exit) {
while (sdlPollEvent(event) != 0) {
}
if (event.type == SDL_QUIT) { exit = true; }
sdlRenderClear(renderer);
sdlRenderPresent(renderer);
}
}
const int SDL_INIT_VIDEO = 0x00000020;
const int SDL_WINDOW_RESIZABLE = 0x00000020;
const int SDL_WINDOW_OPENGL = 0x00000002;
const int SDL_QUIT = 0x100;
const int SDL_RENDERER_ACCELERATED = 0x00000002;
typedef SDL_Init_Native = Int32 Function(Uint32);
typedef SDL_Init = int Function(int);
typedef SDL_CreateWindow_Native = Int64 Function(CString, Int32, Int32, Int32, Int32, Uint32);
typedef SDL_CreateWindow = int Function(CString, int, int, int, int, int);
typedef SDL_PollEvent_Native = Int32 Function(SDL_Event);
typedef SDL_PollEvent = int Function(SDL_Event);
typedef SDL_CreateRenderer_Native = IntPtr Function(IntPtr window, Int32 index, Int32 flags);
typedef SDL_CreateRenderer = int Function(int window, int index, int flags);
typedef SDL_SetRenderDrawColor_Native = Int32 Function(IntPtr renderer, Int8 r, Int8 g, Int8 b, Int8 a);
typedef SDL_SetRenderDrawColor = int Function(int renderer, int r, int g, int b, int a);
typedef SDL_RenderClear_Native = Int32 Function(IntPtr renderer);
typedef SDL_RenderClear = int Function(int renderer);
typedef SDL_RenderPresent_Native = Void Function(IntPtr renderer);
typedef SDL_RenderPresent = void Function(int renderer);
@struct
class SDL_Event extends Pointer<Void> {
@Uint32()
int type;
@Uint32()
int timestamp;
@Uint32()
int windowID;
@Uint8()
int event;
@Uint8()
int p1;
@Uint8()
int p2;
@Uint8()
int p3;
@Int32()
int data1;
@Int32()
int data2;
@Uint32()
int p4;
@Uint32()
int p5;
@Uint32()
int p6;
@Uint32()
int p7;
@Uint32()
int p8;
@Uint32()
int p9;
@Uint32()
int p10;
@Uint32()
int p11;
external static int sizeOf();
factory SDL_Event(int type) {
SDL_Event result = allocate<Uint8>(count: 1 * sizeOf()).cast()
..type = type;
return result;
}
}
SDL_Init sdlInit;
SDL_CreateWindow sdlCreateWindow;
SDL_CreateRenderer sdlCreateRenderer;
SDL_SetRenderDrawColor sdlSetRenderDrawColor;
SDL_RenderClear sdlRenderClear;
SDL_RenderPresent sdlRenderPresent;
SDL_PollEvent sdlPollEvent;
void loadSDL(DynamicLibrary sdl) {
sdlInit = sdl.lookupFunction<SDL_Init_Native, SDL_Init>('SDL_Init');
sdlCreateWindow = sdl.lookupFunction<SDL_CreateWindow_Native, SDL_CreateWindow>('SDL_CreateWindow');
sdlCreateRenderer = sdl.lookupFunction<SDL_CreateRenderer_Native, SDL_CreateRenderer>('SDL_CreateRenderer');
sdlSetRenderDrawColor = sdl.lookupFunction<SDL_SetRenderDrawColor_Native, SDL_SetRenderDrawColor>('SDL_SetRenderDrawColor');
sdlRenderClear = sdl.lookupFunction<SDL_RenderClear_Native, SDL_RenderClear>('SDL_RenderClear');
sdlRenderPresent = sdl.lookupFunction<SDL_RenderPresent_Native, SDL_RenderPresent>('SDL_RenderPresent');
sdlPollEvent = sdl.lookupFunction<SDL_PollEvent_Native, SDL_PollEvent>('SDL_PollEvent');
}
class CString extends Pointer<Uint8> {
CString elementAt(int index) => super.elementAt(index).cast();
factory CString.fromUtf8(String s) {
CString result = allocate<Uint8>(count: s.length + 1).cast();
List<int> units = Utf8Encoder().convert(s);
for (int i = 0; i < s.length; i++) result.elementAt(i).store(units[i]);
result.elementAt(s.length).store(0);
return result;
}
}
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