Avoid access to StencilBuffer if it is non-existent.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3487 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/CSoftwareDriver2.cpp

@@ -2649,16 +2649,19 @@ void CBurningVideoDriver::drawStencilShadowVolume(const core::vector3df* triangl
 void CBurningVideoDriver::drawStencilShadow(bool clearStencilBuffer, video::SColor leftUpEdge,
 	video::SColor rightUpEdge, video::SColor leftDownEdge, video::SColor rightDownEdge)
 {
+	if (!StencilBuffer)
+		return;
 	// draw a shadow rectangle covering the entire screen using stencil buffer
 	const u32 h = RenderTargetSurface->getDimension().Height;
 	const u32 w = RenderTargetSurface->getDimension().Width;
 	tVideoSample *dst;
 	u32 *stencil;
+	u32* const stencilBase=(u32*) StencilBuffer->lock();
 
 	for ( u32 y = 0; y < h; ++y )
 	{
 		dst = (tVideoSample*)RenderTargetSurface->lock() + ( y * w );
-		stencil = (u32*) StencilBuffer->lock() + ( y * w );
+		stencil =  stencilBase + ( y * w );
 
 		for ( u32 x = 0; x < w; ++x )
 		{

source/Irrlicht/CTRStencilShadow.cpp

@@ -110,14 +110,12 @@ CTRStencilShadow::CTRStencilShadow(CBurningVideoDriver* driver)
 }
 
 
-
 /*!
 */
 void CTRStencilShadow::setParam ( u32 index, f32 value)
 {
 	u32 val = (u32) value;
 
-	
 	// glStencilOp (fail,zfail,zpass
 	if ( index == 1 && val == 1 )
 	{
@@ -128,14 +126,14 @@ void CTRStencilShadow::setParam ( u32 index, f32 value)
 	{
 		fragmentShader = &CTRStencilShadow::fragment_zfail_decr;
 	}
-
-
 }
 
 /*!
 */
 void CTRStencilShadow::fragment_zfail_decr ()
 {
+	if (!Stencil)
+		return;
 	//tVideoSample *dst;
 
 #ifdef USE_ZBUFFER
@@ -150,7 +148,6 @@ void CTRStencilShadow::fragment_zfail_decr ()
 	s32 xEnd;
 	s32 dx;
 
-
 #ifdef SUBTEXEL
 	f32 subPixel;
 #endif
@@ -285,13 +282,14 @@ void CTRStencilShadow::fragment_zfail_decr ()
 		line.l[0][0] += slopeL[0];
 #endif
 	}
-
 }
 
 /*!
 */
-void CTRStencilShadow::fragment_zfail_incr ()
+void CTRStencilShadow::fragment_zfail_incr()
 {
+	if (!Stencil)
+		return;
 	//tVideoSample *dst;
 
 #ifdef USE_ZBUFFER
@@ -396,12 +394,10 @@ void CTRStencilShadow::fragment_zfail_incr ()
 	stencil = (u32*) Stencil->lock() + ( line.y * RenderTarget->getDimension().Width ) + xStart;
 #endif
 
-
 #ifdef INVERSE_W
 	f32 inversew;
 #endif
 
-
 #ifdef IPOL_C0
 	tFixPoint r3, g3, b3;
 #endif
@@ -441,7 +437,6 @@ void CTRStencilShadow::fragment_zfail_incr ()
 		line.l[0][0] += slopeL[0];
 #endif
 	}
-
 }
 
 void CTRStencilShadow::drawTriangle ( const s4DVertex *a,const s4DVertex *b,const s4DVertex *c )
@@ -520,7 +515,6 @@ void CTRStencilShadow::drawTriangle ( const s4DVertex *a,const s4DVertex *b,cons
 	f32 subPixel;
 #endif
 
-
 	// rasterize upper sub-triangle
 	//if ( (f32) 0.0 != scan.invDeltaY[1]  )
 	if ( F32_GREATER_0 ( scan.invDeltaY[1] )  )