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Implemented clipping on Windows. Phew!

This commit is contained in:
Pietro Gagliardi 2015-10-13 13:20:25 -04:00
parent cc827919b8
commit b5ac921988
2 changed files with 138 additions and 1 deletions
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4
test/drawtests.c
View File

@ -1,6 +1,10 @@
// 9 october 2015
#include "test.h"
// TODO
// - test multiple clips
// - test saving and restoring clips
struct drawtest {
const char *name;
void (*draw)(uiAreaDrawParams *p);

135
windows/draw.c
View File

@ -96,7 +96,6 @@ uiDrawPath *uiDrawNewPath(uiDrawFillMode fillmode)
D2D1_FILL_MODE_ALTERNATE);
break;
}
p->inFigure = FALSE;
return p;
}
@ -311,6 +310,7 @@ void uiDrawPathEnd(uiDrawPath *p)
struct uiDrawContext {
ID2D1RenderTarget *rt;
UT_array *states;
ID2D1PathGeometry *currentClip;
};
// declared below
@ -342,6 +342,8 @@ uiDrawContext *newContext(ID2D1RenderTarget *rt)
void freeContext(uiDrawContext *c)
{
if (c->currentClip != NULL)
ID2D1PathGeometry_Release(c->currentClip);
uninitStates(c);
uiFree(c);
}
@ -480,11 +482,77 @@ static ID2D1Brush *makeBrush(uiDrawBrush *b, ID2D1RenderTarget *rt)
return NULL; // make compiler happy
}
// how clipping works:
// every fill and stroke is done on a temporary layer with the clip geometry applied to it
// this is really the only way to clip in Direct2D that doesn't involve opacity images
// reference counting:
// - initially the clip is NULL, which means do not use a layer
// - the first time uiDrawClip() is called, we take a reference on the path passed in (this is also why uiPathEnd() is needed)
// - every successive time, we create a new PathGeometry and merge the current clip with the new path, releasing the reference we took earlier and taking a reference to the new one
// - in Save, we take another reference; in Restore we drop the refernece to the existing path geometry and transfer that saved ref to the new path geometry over to the context
// uiDrawFreePath() doesn't destroy the path geometry, it just drops the reference count, so a clip can exist independent of its path
static ID2D1Layer *applyClip(uiDrawContext *c)
{
ID2D1Layer *layer;
D2D1_LAYER_PARAMETERS params;
HRESULT hr;
// if no clip, don't do anything
if (c->currentClip == NULL)
return NULL;
// create a layer for clipping
// we have to explicitly make the layer because we're still targeting Windows 7
// TODO MINGW BUG
// this macro is supposed to take three parameters
hr = (*(c->rt->lpVtbl->CreateLayer))(c->rt,
NULL,
&layer);
if (hr != S_OK)
logHRESULT("error creating clip layer in applyClip()", hr);
// apply it as the clip
ZeroMemory(&params, sizeof (D2D1_LAYER_PARAMETERS));
// this is the equivalent of InfiniteRect() in d2d1helper.h
params.contentBounds.left = -FLT_MAX;
params.contentBounds.top = -FLT_MAX;
params.contentBounds.right = FLT_MAX;
params.contentBounds.bottom = FLT_MAX;
params.geometricMask = (ID2D1Geometry *) (c->currentClip);
// TODO is this correct?
params.maskAntialiasMode = ID2D1RenderTarget_GetAntialiasMode(c->rt);
// identity matrix
params.maskTransform._11 = 1;
params.maskTransform._22 = 1;
params.opacity = 1.0;
params.opacityBrush = NULL;
params.layerOptions = D2D1_LAYER_OPTIONS_NONE;
// TODO is this correct?
if (ID2D1RenderTarget_GetTextAntialiasMode(c->rt) == D2D1_TEXT_ANTIALIAS_MODE_CLEARTYPE)
params.layerOptions = D2D1_LAYER_OPTIONS_INITIALIZE_FOR_CLEARTYPE;
ID2D1RenderTarget_PushLayer(c->rt,
&params,
layer);
// return the layer so it can be freed later
return layer;
}
static void unapplyClip(uiDrawContext *c, ID2D1Layer *layer)
{
if (layer == NULL)
return;
ID2D1RenderTarget_PopLayer(c->rt);
ID2D1Layer_Release(layer);
}
void uiDrawStroke(uiDrawContext *c, uiDrawPath *p, uiDrawBrush *b, uiDrawStrokeParams *sp)
{
ID2D1Brush *brush;
ID2D1StrokeStyle *style;
D2D1_STROKE_STYLE_PROPERTIES dsp;
ID2D1Layer *cliplayer;
HRESULT hr;
brush = makeBrush(b, c->rt);
@ -529,11 +597,13 @@ void uiDrawStroke(uiDrawContext *c, uiDrawPath *p, uiDrawBrush *b, uiDrawStrokeP
if (hr != S_OK)
logHRESULT("error creating stroke style in uiDrawStroke()", hr);
cliplayer = applyClip(c);
ID2D1RenderTarget_DrawGeometry(c->rt,
(ID2D1Geometry *) (p->path),
brush,
sp->Thickness,
style);
unapplyClip(c, cliplayer);
ID2D1StrokeStyle_Release(style);
ID2D1Brush_Release(brush);
@ -542,12 +612,15 @@ void uiDrawStroke(uiDrawContext *c, uiDrawPath *p, uiDrawBrush *b, uiDrawStrokeP
void uiDrawFill(uiDrawContext *c, uiDrawPath *p, uiDrawBrush *b)
{
ID2D1Brush *brush;
ID2D1Layer *cliplayer;
brush = makeBrush(b, c->rt);
cliplayer = applyClip(c);
ID2D1RenderTarget_FillGeometry(c->rt,
(ID2D1Geometry *) (p->path),
brush,
NULL);
unapplyClip(c, cliplayer);
ID2D1Brush_Release(brush);
}
@ -674,8 +747,57 @@ void uiDrawTransform(uiDrawContext *c, uiDrawMatrix *m)
ID2D1RenderTarget_SetTransform(c->rt, &dm);
}
// TODO for this, stroke, and fill, make sure that an open path causes error state
void uiDrawClip(uiDrawContext *c, uiDrawPath *path)
{
ID2D1PathGeometry *newPath;
ID2D1GeometrySink *newSink;
HRESULT hr;
// if there's no current clip, borrow the path
if (c->currentClip == NULL) {
c->currentClip = path->path;
// we have to take our own reference to that clip
ID2D1PathGeometry_AddRef(c->currentClip);
return;
}
// otherwise we have to intersect the current path with the new one
// we do that into a new path, and then replace c->currentClip with that new path
hr = ID2D1Factory_CreatePathGeometry(d2dfactory,
&newPath);
if (hr != S_OK)
logHRESULT("error creating new path in uiDrawClip()", hr);
hr = ID2D1PathGeometry_Open(newPath,
&newSink);
if (hr != S_OK)
logHRESULT("error opening new path in uiDrawClip()", hr);
// TODO BUG IN MINGW
// the macro is supposed to take 6 parameters
hr = (*(c->currentClip->lpVtbl->Base.CombineWithGeometry))(
(ID2D1Geometry *) (c->currentClip),
(ID2D1Geometry *) (path->path),
D2D1_COMBINE_MODE_INTERSECT,
NULL,
// TODO is this correct or can this be set per target?
D2D1_DEFAULT_FLATTENING_TOLERANCE,
(ID2D1SimplifiedGeometrySink *) newSink);
if (hr != S_OK)
logHRESULT("error intersecting old path with new path in uiDrawClip()", hr);
hr = ID2D1GeometrySink_Close(newSink);
if (hr != S_OK)
logHRESULT("error closing new path in uiDrawClip()", hr);
ID2D1GeometrySink_Release(newSink);
// okay we have the new clip; we just need to replace the old one with it
ID2D1PathGeometry_Release(c->currentClip);
c->currentClip = newPath;
// we have a reference already; no need for another
}
struct state {
ID2D1DrawingStateBlock *dsb;
ID2D1PathGeometry *clip;
};
static const UT_icd stateicd = {
@ -712,7 +834,12 @@ void uiDrawSave(uiDrawContext *c)
logHRESULT("error creating drawing state block in uiDrawSave()", hr);
ID2D1RenderTarget_SaveDrawingState(c->rt, dsb);
// if we have a clip, we need to hold another reference to it
if (c->currentClip != NULL)
ID2D1PathGeometry_AddRef(c->currentClip);
state.dsb = dsb;
state.clip = c->currentClip;
utarray_push_back(c->states, &state);
}
@ -725,5 +852,11 @@ void uiDrawRestore(uiDrawContext *c)
ID2D1RenderTarget_RestoreDrawingState(c->rt, state->dsb);
ID2D1DrawingStateBlock_Release(state->dsb);
// if we have a current clip, we need to drop it
if (c->currentClip != NULL)
ID2D1PathGeometry_Release(c->currentClip);
// no need to explicitly addref or release; just transfer the ref
c->currentClip = state->clip;
utarray_pop_back(c->states);
}