fix [#27662] Storing png/tga images ignore Alpha settings

- don't clear alpha when baking RGB images
- when baking results in partial alpha. set the depth to 32.

5 files changed, 57 insertions, 7 deletions

diff --git a/source/blender/blenpluginapi/iff.h b/source/blender/blenpluginapi/iff.h
index bccc7bdb769..77cdf889ea5 100644
--- a/source/blender/blenpluginapi/iff.h
+++ b/source/blender/blenpluginapi/iff.h
@@ -113,9 +113,10 @@ LIBIMPORT void interlace(struct ImBuf *ib);
 LIBIMPORT void IMB_rectcpy(struct ImBuf *dbuf, struct ImBuf *sbuf, 
 	int destx, int desty, int srcx, int srcy, int width, int height);
 
-LIBIMPORT void IMB_rectfill(struct ImBuf *drect, float col[4]);
+LIBIMPORT void IMB_rectfill(struct ImBuf *drect, const float col[4]);
 LIBIMPORT void IMB_rectfill_area(struct ImBuf *ibuf, float *col, int x1, int y1, int x2, int y2);
 LIBIMPORT void buf_rectfill_area(unsigned char *rect, float *rectf, int width, int height, float *col, int x1, int y1, int x2, int y2);
+LIBIMPORT void IMB_rectfill_alpha(struct ImBuf *drect, const float value);
 
 #endif /* IFF_H */
 
diff --git a/source/blender/editors/object/object_bake.c b/source/blender/editors/object/object_bake.c
index 565c5810cff..c669a69b157 100644
--- a/source/blender/editors/object/object_bake.c
+++ b/source/blender/editors/object/object_bake.c
@@ -854,10 +854,14 @@ static void finish_images(MultiresBakeRender *bkr)
 		Image *ima= (Image*)link->data;
 		int i;
 		ImBuf *ibuf= BKE_image_get_ibuf(ima, NULL);
+		short is_new_alpha;
 
 		if(ibuf->x<=0 || ibuf->y<=0)
 			continue;
 
+		/* must check before filtering */
+		is_new_alpha= (ibuf->depth != 32) && BKE_alphatest_ibuf(ibuf);
+
 		/* Margin */
 		if(bkr->bake_filter) {
 			char *temprect;
@@ -882,6 +886,18 @@ static void finish_images(MultiresBakeRender *bkr)
 				IMB_filter_extend(ibuf, (char *)ibuf->userdata);
 		}
 
+		/* if the bake results in new alpha then change the image setting */
+		if(is_new_alpha) {
+			ibuf->depth= 32;
+		}
+		else {
+			if(bkr->bake_filter) {
+				/* clear alpha added by filtering */
+				IMB_rectfill_alpha(ibuf, 1.0f);
+			}
+		}
+
+
 		ibuf->userflags|= IB_BITMAPDIRTY;
 		if(ibuf->mipmap[0]) {
 			ibuf->userflags|= IB_MIPMAP_INVALID;
@@ -1028,7 +1044,8 @@ static DerivedMesh *multiresbake_create_hiresdm(Scene *scene, Object *ob, int *l
 static void clear_images(MTFace *mtface, int totface)
 {
 	int a;
-	float vec[4]= {0.0f, 0.0f, 0.0f, 0.0f};
+	const float vec_alpha[4]= {0.0f, 0.0f, 0.0f, 0.0f};
+	const float vec_solid[4]= {0.0f, 0.0f, 0.0f, 1.0f};
 
 	for(a= 0; a<totface; a++)
 		mtface[a].tpage->id.flag&= ~LIB_DOIT;
@@ -1039,7 +1056,7 @@ static void clear_images(MTFace *mtface, int totface)
 		if((ima->id.flag&LIB_DOIT)==0) {
 			ImBuf *ibuf= BKE_image_get_ibuf(ima, NULL);
 
-			IMB_rectfill(ibuf, vec);
+			IMB_rectfill(ibuf, (ibuf->depth == 32) ? vec_alpha : vec_solid);
 			ima->id.flag|= LIB_DOIT;
 		}
 	}
diff --git a/source/blender/imbuf/IMB_imbuf.h b/source/blender/imbuf/IMB_imbuf.h
index 5d61452e149..e9592fdc164 100644
--- a/source/blender/imbuf/IMB_imbuf.h
+++ b/source/blender/imbuf/IMB_imbuf.h
@@ -442,8 +442,9 @@ void IMB_freezbuffloatImBuf(struct ImBuf *ibuf);
  *
  * @attention Defined in rectop.c
  */
-void IMB_rectfill(struct ImBuf *drect, float col[4]);
+void IMB_rectfill(struct ImBuf *drect, const float col[4]);
 void IMB_rectfill_area(struct ImBuf *ibuf, float *col, int x1, int y1, int x2, int y2);
+void IMB_rectfill_alpha(struct ImBuf *ibuf, const float value);
 
 /* this should not be here, really, we needed it for operating on render data, IMB_rectfill_area calls it */
 void buf_rectfill_area(unsigned char *rect, float *rectf, int width, int height, float *col, int x1, int y1, int x2, int y2);
diff --git a/source/blender/imbuf/intern/rectop.c b/source/blender/imbuf/intern/rectop.c
index 44af7ffdb3f..844478e03cb 100644
--- a/source/blender/imbuf/intern/rectop.c
+++ b/source/blender/imbuf/intern/rectop.c
@@ -450,7 +450,7 @@ void IMB_rectblend(struct ImBuf *dbuf, struct ImBuf *sbuf, int destx,
 
 /* fill */
 
-void IMB_rectfill(struct ImBuf *drect, float col[4])
+void IMB_rectfill(struct ImBuf *drect, const float col[4])
 {
 	int num;
 
@@ -561,3 +561,18 @@ void IMB_rectfill_area(struct ImBuf *ibuf, float *col, int x1, int y1, int x2, i
 	if (!ibuf) return;
 	buf_rectfill_area((unsigned char *) ibuf->rect, ibuf->rect_float, ibuf->x, ibuf->y, col, x1, y1, x2, y2);
 }
+
+
+void IMB_rectfill_alpha(ImBuf *ibuf, const float value)
+{
+	int i;
+	if (ibuf->rect_float) {
+		float *fbuf= ibuf->rect_float + 3;
+		for (i = ibuf->x * ibuf->y; i > 0; i--, fbuf+= 4) { *fbuf = value; }
+	}
+	else {
+		const unsigned char cvalue= value * 255;
+		unsigned char *cbuf= ((unsigned char *)ibuf->rect) + 3;
+		for (i = ibuf->x * ibuf->y; i > 0; i--, cbuf+= 4) { *cbuf = cvalue; }
+	}
+}
diff --git a/source/blender/render/intern/source/rendercore.c b/source/blender/render/intern/source/rendercore.c
index 0087be8cca9..e6206007b7a 100644
--- a/source/blender/render/intern/source/rendercore.c
+++ b/source/blender/render/intern/source/rendercore.c
@@ -2464,7 +2464,8 @@ static int get_next_bake_face(BakeShade *bs)
 				if(tface && tface->tpage) {
 					Image *ima= tface->tpage;
 					ImBuf *ibuf= BKE_image_get_ibuf(ima, NULL);
-					float vec[4]= {0.0f, 0.0f, 0.0f, 0.0f};
+					const float vec_alpha[4]= {0.0f, 0.0f, 0.0f, 0.0f};
+					const float vec_solid[4]= {0.0f, 0.0f, 0.0f, 1.0f};
 					
 					if(ibuf==NULL)
 						continue;
@@ -2484,7 +2485,7 @@ static int get_next_bake_face(BakeShade *bs)
 							imb_freerectImBuf(ibuf);
 						/* clear image */
 						if(R.r.bake_flag & R_BAKE_CLEAR)
-							IMB_rectfill(ibuf, vec);
+							IMB_rectfill(ibuf, (ibuf->depth == 32) ? vec_alpha : vec_solid);
 					
 						/* might be read by UI to set active image for display */
 						R.bakebuf= ima;
@@ -2671,10 +2672,14 @@ int RE_bake_shade_all_selected(Render *re, int type, Object *actob, short *do_up
 	for(ima= G.main->image.first; ima; ima= ima->id.next) {
 		if((ima->id.flag & LIB_DOIT)==0) {
 			ImBuf *ibuf= BKE_image_get_ibuf(ima, NULL);
+			short is_new_alpha;
 
 			if(!ibuf)
 				continue;
 
+			/* must check before filtering */
+			is_new_alpha= (ibuf->depth != 32) && BKE_alphatest_ibuf(ibuf);
+
 			if(re->r.bake_filter) {
 				if (usemask) {
 					/* extend the mask +2 pixels from the image,
@@ -2706,6 +2711,17 @@ int RE_bake_shade_all_selected(Render *re, int type, Object *actob, short *do_up
 				}
 			}
 
+			/* if the bake results in new alpha then change the image setting */
+			if(is_new_alpha) {
+				ibuf->depth= 32;
+			}
+			else {
+				if(re->r.bake_filter) {
+					/* clear alpha added by filtering */
+					IMB_rectfill_alpha(ibuf, 1.0f);
+				}
+			}
+
 			ibuf->userflags |= IB_BITMAPDIRTY;
 			if (ibuf->rect_float) IMB_rect_from_float(ibuf);
 		}