Bugfix #4558

Thread render error: a flag was stored in read-only data to indicate
whether top or bottom hemisphere of sky was rendered. That can't work
with tiles (but did work when scanlines were threads).

3 files changed, 10 insertions, 8 deletions

diff --git a/source/blender/render/intern/include/texture.h b/source/blender/render/intern/include/texture.h
index 59c842559f4..13ab6f7cd67 100644
--- a/source/blender/render/intern/include/texture.h
+++ b/source/blender/render/intern/include/texture.h
@@ -55,7 +55,7 @@ struct Image;
 /* texture.h */
 
 void do_halo_tex(struct HaloRen *har, float xn, float yn, float *colf);
-void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, float *blend);
+void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, float *blend, int skyflag);
 void do_material_tex(struct ShadeInput *shi);
 void do_lamp_tex(LampRen *la, float *lavec, struct ShadeInput *shi, float *colf);
 
diff --git a/source/blender/render/intern/source/pixelshading.c b/source/blender/render/intern/source/pixelshading.c
index 9dff90dda0c..fbd7d4ee04d 100644
--- a/source/blender/render/intern/source/pixelshading.c
+++ b/source/blender/render/intern/source/pixelshading.c
@@ -551,16 +551,18 @@ void shadeSkyPixel(float *collector, float fx, float fy, float *rco)
 void shadeSkyPixelFloat(float *colf, float *rco, float *view, float *dxyview)
 {
 	float lo[3], zen[3], hor[3], blend, blendm;
+	int skyflag;
 	
-	/* Why is this setting forced? Seems silly to me. It is tested in the texture unit. */
-	R.wrld.skytype |= WO_ZENUP;
+	/* flag indicating if we render the top hemisphere */
+	skyflag = WO_ZENUP;
 	
 	/* Some view vector stuff. */
 	if(R.wrld.skytype & WO_SKYREAL) {
 	
 		blend= view[0]*R.grvec[0]+ view[1]*R.grvec[1]+ view[2]*R.grvec[2];
 
-		if(blend<0.0) R.wrld.skytype-= WO_ZENUP;
+		if(blend<0.0) skyflag= 0;
+		
 		blend= fabs(blend);
 	}
 	else if(R.wrld.skytype & WO_SKYPAPER) {
@@ -585,7 +587,7 @@ void shadeSkyPixelFloat(float *colf, float *rco, float *view, float *dxyview)
 			SWAP(float, lo[1],  lo[2]);
 			
 		}
-		do_sky_tex(rco, lo, dxyview, hor, zen, &blend);
+		do_sky_tex(rco, lo, dxyview, hor, zen, &blend, skyflag);
 	}
 
 	if(blend>1.0) blend= 1.0;
diff --git a/source/blender/render/intern/source/texture.c b/source/blender/render/intern/source/texture.c
index 46001855b2a..dd6092d4a1b 100644
--- a/source/blender/render/intern/source/texture.c
+++ b/source/blender/render/intern/source/texture.c
@@ -2024,7 +2024,7 @@ void do_halo_tex(HaloRen *har, float xn, float yn, float *colf)
 /* ------------------------------------------------------------------------- */
 
 /* hor and zen are RGB vectors, blend is 1 float, should all be initialized */
-void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, float *blend)
+void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, float *blend, int skyflag)
 {
 	MTex *mtex;
 	TexResult texres;
@@ -2068,7 +2068,7 @@ void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, f
 			
 			case TEXCO_H_SPHEREMAP:
 			case TEXCO_H_TUBEMAP:
-				if(R.wrld.skytype & WO_ZENUP) {
+				if(skyflag & WO_ZENUP) {
 					if(mtex->texco==TEXCO_H_TUBEMAP) tubemap(lo[0], lo[2], lo[1], tempvec, tempvec+1);
 					else spheremap(lo[0], lo[2], lo[1], tempvec, tempvec+1);
 					/* tube/spheremap maps for outside view, not inside */
@@ -2174,7 +2174,7 @@ void do_sky_tex(float *rco, float *lo, float *dxyview, float *hor, float *zen, f
 				if(mtex->mapto & (WOMAP_ZENUP+WOMAP_ZENDOWN)) {
 					ok= 0;
 					if(R.wrld.skytype & WO_SKYREAL) {
-						if((R.wrld.skytype & WO_ZENUP)) {
+						if((skyflag & WO_ZENUP)) {
 							if(mtex->mapto & WOMAP_ZENUP) ok= 1;
 						}
 						else if(mtex->mapto & WOMAP_ZENDOWN) ok= 1;