4 files changed, 23 insertions, 7 deletions

diff --git a/intern/cycles/device/device.cpp b/intern/cycles/device/device.cpp
index cd0d64f37dd..2f2d34dcef2 100644
--- a/intern/cycles/device/device.cpp
+++ b/intern/cycles/device/device.cpp
@@ -86,10 +86,15 @@ void Device::pixels_free(device_memory& mem)
 	mem_free(mem);
 }
 
-void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int width, int height)
+void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int width, int height, bool transparent)
 {
 	pixels_copy_from(rgba, y, w, h);
 
+	if(transparent) {
+		glEnable(GL_BLEND);
+		glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+	}
+
 	glPixelZoom((float)width/(float)w, (float)height/(float)h);
 	glRasterPos2f(0, y);
 
@@ -97,6 +102,9 @@ void Device::draw_pixels(device_memory& rgba, int y, int w, int h, int width, in
 
 	glRasterPos2f(0.0f, 0.0f);
 	glPixelZoom(1.0f, 1.0f);
+
+	if(transparent)
+		glDisable(GL_BLEND);
 }
 
 Device *Device::create(DeviceType type, bool background, int threads)
diff --git a/intern/cycles/device/device.h b/intern/cycles/device/device.h
index 8006eea1a5f..87683ae4719 100644
--- a/intern/cycles/device/device.h
+++ b/intern/cycles/device/device.h
@@ -115,7 +115,7 @@ public:
 	
 	/* opengl drawing */
 	virtual void draw_pixels(device_memory& mem, int y, int w, int h,
-		int width, int height);
+		int width, int height, bool transparent);
 
 #ifdef WITH_NETWORK
 	/* networking */
diff --git a/intern/cycles/device/device_cuda.cpp b/intern/cycles/device/device_cuda.cpp
index 0537e231f44..cc1c1275bf4 100644
--- a/intern/cycles/device/device_cuda.cpp
+++ b/intern/cycles/device/device_cuda.cpp
@@ -607,7 +607,7 @@ public:
 		}
 	}
 
-	void draw_pixels(device_memory& mem, int y, int w, int h, int width, int height)
+	void draw_pixels(device_memory& mem, int y, int w, int h, int width, int height, bool transparent)
 	{
 		if(!background) {
 			PixelMem pmem = pixel_mem_map[mem.device_pointer];
@@ -621,11 +621,16 @@ public:
 			
 			glEnable(GL_TEXTURE_2D);
 			
+			if(transparent) {
+				glEnable(GL_BLEND);
+				glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+			}
+
 			glColor3f(1.0f, 1.0f, 1.0f);
 
 			glPushMatrix();
 			glTranslatef(0.0f, (float)y, 0.0f);
-			
+				
 			glBegin(GL_QUADS);
 			
 			glTexCoord2f(0.0f, 0.0f);
@@ -640,6 +645,9 @@ public:
 			glEnd();
 
 			glPopMatrix();
+
+			if(transparent)
+				glDisable(GL_BLEND);
 			
 			glBindTexture(GL_TEXTURE_2D, 0);
 			glDisable(GL_TEXTURE_2D);
@@ -649,7 +657,7 @@ public:
 			return;
 		}
 
-		Device::draw_pixels(mem, y, w, h, width, height);
+		Device::draw_pixels(mem, y, w, h, width, height, transparent);
 	}
 
 	void task_add(DeviceTask& task)
diff --git a/intern/cycles/device/device_multi.cpp b/intern/cycles/device/device_multi.cpp
index e48df93737d..cae63596d3b 100644
--- a/intern/cycles/device/device_multi.cpp
+++ b/intern/cycles/device/device_multi.cpp
@@ -244,7 +244,7 @@ public:
 		mem.device_pointer = tmp;
 	}
 
-	void draw_pixels(device_memory& rgba, int y, int w, int h, int width, int height)
+	void draw_pixels(device_memory& rgba, int y, int w, int h, int width, int height, bool transparent)
 	{
 		device_ptr tmp = rgba.device_pointer;
 		int i = 0, sub_h = h/devices.size();
@@ -255,7 +255,7 @@ public:
 			/* adjust math for w/width */
 
 			rgba.device_pointer = sub.ptr_map[tmp];
-			sub.device->draw_pixels(rgba, sy, w, sh, width, height);
+			sub.device->draw_pixels(rgba, sy, w, sh, width, height, transparent);
 			i++;
 		}