libui/windows/areadraw.cpp

138 lines
3.9 KiB
C++

// 8 september 2015
#include "uipriv_windows.hpp"
#include "area.hpp"
static HRESULT doPaint(uiArea *a, ID2D1RenderTarget *rt, RECT *clip)
{
uiAreaHandler *ah = a->ah;
uiAreaDrawParams dp;
COLORREF bgcolorref;
D2D1_COLOR_F bgcolor;
D2D1_MATRIX_3X2_F scrollTransform;
// no need to save or restore the graphics state to reset transformations; it's handled by resetTarget() in draw.c, called during the following
dp.Context = newContext(rt);
loadAreaSize(a, rt, &(dp.AreaWidth), &(dp.AreaHeight));
dp.ClipX = clip->left;
dp.ClipY = clip->top;
dp.ClipWidth = clip->right - clip->left;
dp.ClipHeight = clip->bottom - clip->top;
if (a->scrolling) {
dp.ClipX += a->hscrollpos;
dp.ClipY += a->vscrollpos;
}
rt->BeginDraw();
if (a->scrolling) {
ZeroMemory(&scrollTransform, sizeof (D2D1_MATRIX_3X2_F));
scrollTransform._11 = 1;
scrollTransform._22 = 1;
// negative because we want nonzero scroll positions to move the drawing area up/left
scrollTransform._31 = -a->hscrollpos;
scrollTransform._32 = -a->vscrollpos;
rt->SetTransform(&scrollTransform);
}
// TODO push axis aligned clip
// TODO only clear the clip area
// TODO clear with actual background brush
bgcolorref = GetSysColor(COLOR_BTNFACE);
bgcolor.r = ((float) GetRValue(bgcolorref)) / 255.0;
// due to utter apathy on Microsoft's part, GetGValue() does not work with MSVC's Run-Time Error Checks
// it has not worked since 2008 and they have *never* fixed it
// TODO now that -RTCc has just been deprecated entirely, should we switch back?
bgcolor.g = ((float) ((BYTE) ((bgcolorref & 0xFF00) >> 8))) / 255.0;
bgcolor.b = ((float) GetBValue(bgcolorref)) / 255.0;
bgcolor.a = 1.0;
rt->Clear(&bgcolor);
(*(ah->Draw))(ah, a, &dp);
freeContext(dp.Context);
// TODO pop axis aligned clip
return rt->EndDraw(NULL, NULL);
}
static void onWM_PAINT(uiArea *a)
{
RECT clip;
HRESULT hr;
// do not clear the update rect; we do that ourselves in doPaint()
if (GetUpdateRect(a->hwnd, &clip, FALSE) == 0) {
// set a zero clip rect just in case GetUpdateRect() didn't change clip
clip.left = 0;
clip.top = 0;
clip.right = 0;
clip.bottom = 0;
}
hr = doPaint(a, a->rt, &clip);
switch (hr) {
case S_OK:
if (ValidateRect(a->hwnd, NULL) == 0)
logLastError(L"error validating rect");
break;
case D2DERR_RECREATE_TARGET:
// DON'T validate the rect
// instead, simply drop the render target
// we'll get another WM_PAINT and make the render target again
// TODO would this require us to invalidate the entire client area?
a->rt->Release();;
a->rt = NULL;
break;
default:
logHRESULT(L"error painting", hr);
}
}
static void onWM_PRINTCLIENT(uiArea *a, HDC dc)
{
ID2D1DCRenderTarget *rt;
RECT client;
HRESULT hr;
uiWindowsEnsureGetClientRect(a->hwnd, &client);
rt = makeHDCRenderTarget(dc, &client);
hr = doPaint(a, rt, &client);
if (hr != S_OK)
logHRESULT(L"error printing uiArea client area", hr);
rt->Release();
}
BOOL areaDoDraw(uiArea *a, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT *lResult)
{
switch (uMsg) {
case WM_PAINT:
onWM_PAINT(a);
*lResult = 0;
return TRUE;
case WM_PRINTCLIENT:
onWM_PRINTCLIENT(a, (HDC) wParam);
*lResult = 0;
return TRUE;
}
return FALSE;
}
// TODO only if the render target wasn't just created?
void areaDrawOnResize(uiArea *a, RECT *newClient)
{
D2D1_SIZE_U size;
size.width = newClient->right - newClient->left;
size.height = newClient->bottom - newClient->top;
// don't track the error; we'll get that in EndDraw()
// see https://msdn.microsoft.com/en-us/library/windows/desktop/dd370994%28v=vs.85%29.aspx
a->rt->Resize(&size);
// according to Rick Brewster, we must always redraw the entire client area after calling ID2D1RenderTarget::Resize() (see http://stackoverflow.com/a/33222983/3408572)
// we used to have a uiAreaHandler.RedrawOnResize() method to decide this; now you know why we don't anymore
invalidateRect(a->hwnd, NULL, TRUE);
}