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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "_cgo_export.h"
#include "windriver.h"
static HBITMAP mkbitmap(HDC dc, RECT *r, VOID **ppvBits) {
BITMAPINFO bi;
LONG dx, dy;
HBITMAP bitmap;
dx = r->right - r->left;
dy = r->bottom - r->top;
ZeroMemory(&bi, sizeof (BITMAPINFO));
bi.bmiHeader.biSize = sizeof (BITMAPINFOHEADER);
bi.bmiHeader.biWidth = (LONG) dx;
bi.bmiHeader.biHeight = -((LONG) dy); // negative height to force top-down drawing
bi.bmiHeader.biPlanes = 1;
bi.bmiHeader.biBitCount = 32;
bi.bmiHeader.biCompression = BI_RGB;
bi.bmiHeader.biSizeImage = (DWORD) (dx * dy * 4);
bitmap = CreateDIBSection(dc, &bi, DIB_RGB_COLORS, ppvBits, 0, 0);
if (bitmap == NULL) {
// TODO(andlabs)
}
return bitmap;
}
static void blend(HDC dc, HBITMAP bitmap, RECT *dr, LONG sdx, LONG sdy) {
HDC compatibleDC;
HBITMAP prevBitmap;
BLENDFUNCTION blendfunc;
compatibleDC = CreateCompatibleDC(dc);
if (compatibleDC == NULL) {
// TODO(andlabs)
}
prevBitmap = SelectObject(compatibleDC, bitmap);
if (prevBitmap == NULL) {
// TODO(andlabs)
}
ZeroMemory(&blendfunc, sizeof (BLENDFUNCTION));
blendfunc.BlendOp = AC_SRC_OVER;
blendfunc.BlendFlags = 0;
blendfunc.SourceConstantAlpha = 255; // only use per-pixel alphas
blendfunc.AlphaFormat = AC_SRC_ALPHA; // premultiplied
if (AlphaBlend(dc, dr->left, dr->top,
dr->right - dr->left, dr->bottom - dr->top,
compatibleDC, 0, 0, sdx, sdy,
blendfunc) == FALSE) {
// TODO
}
// TODO(andlabs): error check these?
SelectObject(compatibleDC, prevBitmap);
DeleteDC(compatibleDC);
}
// TODO(andlabs): Upload
void fillSrc(HDC dc, RECT *r, COLORREF color) {
HBRUSH brush;
// COLORREF is 0x00BBGGRR; color is 0xAARRGGBB
color = RGB((color >> 16) & 0xFF,
(color >> 8) & 0xFF,
color & 0xFF);
brush = CreateSolidBrush(color);
if (brush == NULL) {
// TODO
}
if (FillRect(dc, r, brush) == 0) {
// TODO
}
// TODO(andlabs) check errors?
DeleteObject(brush);
}
void fillOver(HDC dc, RECT *r, COLORREF color) {
HBITMAP bitmap;
VOID *ppvBits;
RECT oneByOne;
// AlphaBlend will stretch the input image (using StretchBlt's
// COLORONCOLOR mode) to fill the output rectangle. Testing
// this shows that the result appears to be the same as if we had
// used a MxN bitmap instead.
oneByOne.left = 0;
oneByOne.top = 0;
oneByOne.right = 1;
oneByOne.bottom = 1;
bitmap = mkbitmap(dc, &oneByOne, &ppvBits);
*((uint32_t *) ppvBits) = color;
blend(dc, bitmap, r, 1, 1);
// TODO(andlabs): check errors?
DeleteObject(bitmap);
}
// TODO(andlabs): Draw
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