SwapBuffers

関数

前面と背面のバッファを入れ替えて描画結果を表示する。

DLLGDI32.dll呼出規約winapiSetLastErrorあり対応OSWindows 2000 以降

シグネチャ

// GDI32.dll
#include <windows.h>

BOOL SwapBuffers(
    HDC param0
);

パラメーター

名前	型	方向
param0	HDC	in

戻り値の型: BOOL

各言語での呼び出し定義

// GDI32.dll
#include <windows.h>

BOOL SwapBuffers(
    HDC param0
);

[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("GDI32.dll", SetLastError = true, ExactSpelling = true)]
static extern bool SwapBuffers(
    IntPtr param0   // HDC
);

<DllImport("GDI32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function SwapBuffers(
    param0 As IntPtr   ' HDC
) As Boolean
End Function

' param0 : HDC
Declare PtrSafe Function SwapBuffers Lib "gdi32" ( _
    ByVal param0 As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

SwapBuffers = ctypes.windll.gdi32.SwapBuffers
SwapBuffers.restype = wintypes.BOOL
SwapBuffers.argtypes = [
    wintypes.HANDLE,  # param0 : HDC
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('GDI32.dll')
SwapBuffers = Fiddle::Function.new(
  lib['SwapBuffers'],
  [
    Fiddle::TYPE_VOIDP,  # param0 : HDC
  ],
  Fiddle::TYPE_INT)

#[link(name = "gdi32")]
extern "system" {
    fn SwapBuffers(
        param0: *mut core::ffi::c_void  // HDC
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("GDI32.dll", SetLastError = true)]
public static extern bool SwapBuffers(IntPtr param0);
"@
$api = Add-Type -MemberDefinition $sig -Name 'GDI32_SwapBuffers' -Namespace Win32 -PassThru
# $api::SwapBuffers(param0)

#uselib "GDI32.dll"
#func global SwapBuffers "SwapBuffers" sptr
; SwapBuffers param0   ; 戻り値は stat
; param0 : HDC -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "GDI32.dll"
#cfunc global SwapBuffers "SwapBuffers" sptr
; res = SwapBuffers(param0)
; param0 : HDC -> "sptr"

; BOOL SwapBuffers(HDC param0)
#uselib "GDI32.dll"
#cfunc global SwapBuffers "SwapBuffers" intptr
; res = SwapBuffers(param0)
; param0 : HDC -> "intptr"

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	gdi32 = windows.NewLazySystemDLL("GDI32.dll")
	procSwapBuffers = gdi32.NewProc("SwapBuffers")
)

// param0 (HDC)
r1, _, err := procSwapBuffers.Call(
	uintptr(param0),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function SwapBuffers(
  param0: THandle   // HDC
): BOOL; stdcall;
  external 'GDI32.dll' name 'SwapBuffers';

result := DllCall("GDI32\SwapBuffers"
    , "Ptr", param0   ; HDC
    , "Int")   ; return: BOOL

●SwapBuffers(param0) = DLL("GDI32.dll", "bool SwapBuffers(void*)")
# 呼び出し: SwapBuffers(param0)
# param0 : HDC -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。