R21 BaseDraw::DrawPointArray draws squares versus circles in R20

[C4DS]

Hello,

I have yet again a strange behaviour with R21 which I cannot seem to explain.
As always a sample implementation is provided below (without any optimization nor sanity checking)
Same code copied into a R21 plugin and R20 plugin provide different results, see screenshot.

I seem to remember having had the same issue on a Mac Mini running R16 (if I remember correctly). Where the Windows implementation resulted in circular dots, while the Mac displayed square dots. Back then, I assumed it was related to the fact the Mac Mini was using an Intel CPU graphic display, while the Windows machine had a NVidia Geforce 920m running.

However, the R20 and R21 testing is done one the same Windows machine, running next to each other in their respective Visual Studio debug session.

I am trying to think and guess what might be wrong in the R21 implementation, but I just cannot figure out what is missing. I simply copied the whole code, ran it in R20 ... and there all is OK.

// ========================
// Cinema 4D C++ plugin
//
// PluginName: Test
// Dummy "empty" plugin
// ========================

// Main.cpp

#include "c4d.h"

// Dummy IDs - for demonstration purposes only
#define MYSCENEHOOK_PLUGIN_ID	1000000

// ====================================
// SceneHook
// ====================================

class MySceneHook : public SceneHookData
{
	INSTANCEOF(MySceneHook, SceneHookData)

public:
	MySceneHook();
	virtual Bool Draw(BaseSceneHook *node, BaseDocument *doc, BaseDraw *bd, BaseDrawHelp *bh, BaseThread *bt, SCENEHOOKDRAW flags);

	static NodeData *Alloc(void) { return NewObjClear(MySceneHook); }
};

MySceneHook::MySceneHook() : SceneHookData()
{
}

Bool MySceneHook::Draw(BaseSceneHook *node, BaseDocument *doc, BaseDraw *bd, BaseDrawHelp *bh, BaseThread *bt, SCENEHOOKDRAW flags)
{
	if (!node || !doc || !bd || !bh)
		return false;
	if (flags != SCENEHOOKDRAW::DRAW_PASS)
		return true;

	Int32 lLeft, lTop, lRight, lBottom;
	bd->GetFrame(&lLeft, &lTop, &lRight, &lBottom);

	bd->SetMatrix_Screen();

	const Int32 pointCount = 5;
	for (Int32 i = 0; i < pointCount; ++i)
	{
		Float pointSize = 10.0 * i;
		bd->SetPointSize(pointSize);

		iferr(Vector32* vPoints = NewMem(Vector32, pointCount))
			return false;
		vPoints[0] = Vector32(i * 50.0 + (lLeft + lRight) * 0.5, (lTop + lBottom) * 0.5, 0.0);

		const Vector selprevColor = GetViewColor(VIEWCOLOR_SELECTION_PREVIEW);
		bd->SetPen(selprevColor);

		bd->DrawPointArray(pointCount, vPoints);

		DeleteMem(vPoints);
	}

	// restore basedraw matrix
	bd->SetMatrix_Matrix(nullptr, Matrix());

	return true;
}

// ====================================
// Plugin Main 
// ====================================
Bool PluginStart(void)
{
	ApplicationOutput("Test"_s);
	
	RegisterSceneHookPlugin(MYSCENEHOOK_PLUGIN_ID, "MySceneHook"_s, 0, MySceneHook::Alloc, EXECUTIONPRIORITY_GENERATOR, 0);

	return true;
}
void PluginEnd(void)
{
}
Bool PluginMessage(Int32 id, void * data)
{
	switch (id) {
	case C4DPL_INIT_SYS:
		if (!g_resource.Init())
			return false;
		return true;
	case C4DMSG_PRIORITY:
		return true;
	case C4DPL_BUILDMENU:
		break;
	case C4DPL_ENDACTIVITY:
		return true;
	}
	return false;
}

[C4DS]

Apologies for the somewhat incorrect code I provided.
I know notice I had started wanting to draw 5 points, and made an appropriate loop. Then I noticed the point size had to be changed on a per point level, which wasn't possible with a single call to DrawPointArray.

While the result is still the same, here's the intended code (for the drawing method only, all rest remains as original)

Bool MySceneHook::Draw(BaseSceneHook *node, BaseDocument *doc, BaseDraw *bd, BaseDrawHelp *bh, BaseThread *bt, SCENEHOOKDRAW flags)
{
	if (!node || !doc || !bd || !bh)
		return false;
	if (flags != SCENEHOOKDRAW::DRAW_PASS)
		return true;

	Int32 lLeft, lTop, lRight, lBottom;
	bd->GetFrame(&lLeft, &lTop, &lRight, &lBottom);

	bd->SetMatrix_Screen();

	const Int32 loopCount = 5;
	const Int32 pointCount = 1;
	for (Int32 i = 0; i < loopCount; ++i)
	{
		Float pointSize = 10.0 * i;
		bd->SetPointSize(pointSize);

		iferr(Vector32* vPoints = NewMem(Vector32, pointCount))
			return false;
		vPoints[0] = Vector32(i * 50.0 + (lLeft + lRight) * 0.5, (lTop + lBottom) * 0.5, 0.0);

		const Vector selprevColor = GetViewColor(VIEWCOLOR_SELECTION_PREVIEW);
		bd->SetPen(selprevColor);

		bd->DrawPointArray(pointCount, vPoints);

		DeleteMem(vPoints);
	}

	// restore basedraw matrix
	bd->SetMatrix_Matrix(nullptr, Matrix());

	return true;
}

[Manuel]

hello,

To keep you inform, I'm asking the devs and this is taking more time than expected. Sorry for the delay.

Cheers,
Manuel

[Manuel]

Hello

Sorry for the delay, Christmas time didn't helped.
I've opened a bug entry for that issue.
I'll be back when i'll have more information.

I've added the "Bug report" tag to this thread

Cheers,
Manuel