GradientFill

// MSIMG32.dll
#include <windows.h>

BOOL GradientFill(
    HDC hdc,
    TRIVERTEX* pVertex,
    DWORD nVertex,
    void* pMesh,
    DWORD nMesh,
    GRADIENT_FILL ulMode
);

<DllImport("MSIMG32.dll", ExactSpelling:=True)>
Public Shared Function GradientFill(
    hdc As IntPtr,   ' HDC
    pVertex As IntPtr,   ' TRIVERTEX*
    nVertex As UInteger,   ' DWORD
    pMesh As IntPtr,   ' void*
    nMesh As UInteger,   ' DWORD
    ulMode As UInteger   ' GRADIENT_FILL
) As Boolean
End Function

' hdc : HDC
' pVertex : TRIVERTEX*
' nVertex : DWORD
' pMesh : void*
' nMesh : DWORD
' ulMode : GRADIENT_FILL
Declare PtrSafe Function GradientFill Lib "msimg32" ( _
    ByVal hdc As LongPtr, _
    ByVal pVertex As LongPtr, _
    ByVal nVertex As Long, _
    ByVal pMesh As LongPtr, _
    ByVal nMesh As Long, _
    ByVal ulMode As Long) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

GradientFill = ctypes.windll.msimg32.GradientFill
GradientFill.restype = wintypes.BOOL
GradientFill.argtypes = [
    wintypes.HANDLE,  # hdc : HDC
    ctypes.c_void_p,  # pVertex : TRIVERTEX*
    wintypes.DWORD,  # nVertex : DWORD
    ctypes.POINTER(None),  # pMesh : void*
    wintypes.DWORD,  # nMesh : DWORD
    wintypes.DWORD,  # ulMode : GRADIENT_FILL
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('MSIMG32.dll')
GradientFill = Fiddle::Function.new(
  lib['GradientFill'],
  [
    Fiddle::TYPE_VOIDP,  # hdc : HDC
    Fiddle::TYPE_VOIDP,  # pVertex : TRIVERTEX*
    -Fiddle::TYPE_INT,  # nVertex : DWORD
    Fiddle::TYPE_VOIDP,  # pMesh : void*
    -Fiddle::TYPE_INT,  # nMesh : DWORD
    -Fiddle::TYPE_INT,  # ulMode : GRADIENT_FILL
  ],
  Fiddle::TYPE_INT)

#[link(name = "msimg32")]
extern "system" {
    fn GradientFill(
        hdc: *mut core::ffi::c_void,  // HDC
        pVertex: *mut TRIVERTEX,  // TRIVERTEX*
        nVertex: u32,  // DWORD
        pMesh: *mut (),  // void*
        nMesh: u32,  // DWORD
        ulMode: u32  // GRADIENT_FILL
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("MSIMG32.dll")]
public static extern bool GradientFill(IntPtr hdc, IntPtr pVertex, uint nVertex, IntPtr pMesh, uint nMesh, uint ulMode);
"@
$api = Add-Type -MemberDefinition $sig -Name 'MSIMG32_GradientFill' -Namespace Win32 -PassThru
# $api::GradientFill(hdc, pVertex, nVertex, pMesh, nMesh, ulMode)

#uselib "MSIMG32.dll"
#func global GradientFill "GradientFill" sptr, sptr, sptr, sptr, sptr, sptr
; GradientFill hdc, varptr(pVertex), nVertex, pMesh, nMesh, ulMode   ; 戻り値は stat
; hdc : HDC -> "sptr"
; pVertex : TRIVERTEX* -> "sptr"
; nVertex : DWORD -> "sptr"
; pMesh : void* -> "sptr"
; nMesh : DWORD -> "sptr"
; ulMode : GRADIENT_FILL -> "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 "MSIMG32.dll"
#cfunc global GradientFill "GradientFill" sptr, var, int, sptr, int, int
; res = GradientFill(hdc, pVertex, nVertex, pMesh, nMesh, ulMode)
; hdc : HDC -> "sptr"
; pVertex : TRIVERTEX* -> "var"
; nVertex : DWORD -> "int"
; pMesh : void* -> "sptr"
; nMesh : DWORD -> "int"
; ulMode : GRADIENT_FILL -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; BOOL GradientFill(HDC hdc, TRIVERTEX* pVertex, DWORD nVertex, void* pMesh, DWORD nMesh, GRADIENT_FILL ulMode)
#uselib "MSIMG32.dll"
#cfunc global GradientFill "GradientFill" intptr, var, int, intptr, int, int
; res = GradientFill(hdc, pVertex, nVertex, pMesh, nMesh, ulMode)
; hdc : HDC -> "intptr"
; pVertex : TRIVERTEX* -> "var"
; nVertex : DWORD -> "int"
; pMesh : void* -> "intptr"
; nMesh : DWORD -> "int"
; ulMode : GRADIENT_FILL -> "int"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

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

var (
	msimg32 = windows.NewLazySystemDLL("MSIMG32.dll")
	procGradientFill = msimg32.NewProc("GradientFill")
)

// hdc (HDC), pVertex (TRIVERTEX*), nVertex (DWORD), pMesh (void*), nMesh (DWORD), ulMode (GRADIENT_FILL)
r1, _, err := procGradientFill.Call(
	uintptr(hdc),
	uintptr(pVertex),
	uintptr(nVertex),
	uintptr(pMesh),
	uintptr(nMesh),
	uintptr(ulMode),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function GradientFill(
  hdc: THandle;   // HDC
  pVertex: Pointer;   // TRIVERTEX*
  nVertex: DWORD;   // DWORD
  pMesh: Pointer;   // void*
  nMesh: DWORD;   // DWORD
  ulMode: DWORD   // GRADIENT_FILL
): BOOL; stdcall;
  external 'MSIMG32.dll' name 'GradientFill';

result := DllCall("MSIMG32\GradientFill"
    , "Ptr", hdc   ; HDC
    , "Ptr", pVertex   ; TRIVERTEX*
    , "UInt", nVertex   ; DWORD
    , "Ptr", pMesh   ; void*
    , "UInt", nMesh   ; DWORD
    , "UInt", ulMode   ; GRADIENT_FILL
    , "Int")   ; return: BOOL

●GradientFill(hdc, pVertex, nVertex, pMesh, nMesh, ulMode) = DLL("MSIMG32.dll", "bool GradientFill(void*, void*, dword, void*, dword, dword)")
# 呼び出し: GradientFill(hdc, pVertex, nVertex, pMesh, nMesh, ulMode)
# hdc : HDC -> "void*"
# pVertex : TRIVERTEX* -> "void*"
# nVertex : DWORD -> "dword"
# pMesh : void* -> "void*"
# nMesh : DWORD -> "dword"
# ulMode : GRADIENT_FILL -> "dword"
# 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)。