Cycles: multi GPU rendering support.

The rendering device is now set in User Preferences > System, where you can
choose between OpenCL/CUDA and devices. Per scene you can then still choose
to use CPU or GPU rendering.

Load balancing still needs to be improved, now it just splits the entire
render in two, that will be done in a separate commit.

1 files changed, 32 insertions, 23 deletions

diff --git a/intern/cycles/device/device_multi.cpp b/intern/cycles/device/device_multi.cpp
index f8b512f209c..41d0e268526 100644
--- a/intern/cycles/device/device_multi.cpp
+++ b/intern/cycles/device/device_multi.cpp
@@ -163,15 +163,18 @@ public:
 		mem.device_pointer = tmp;
 	}
 
-	void mem_copy_from(device_memory& mem, size_t offset, size_t size)
+	void mem_copy_from(device_memory& mem, int y, int w, int h, int elem)
 	{
 		device_ptr tmp = mem.device_pointer;
+		int i = 0, sub_h = h/devices.size();
 
-		/* todo: how does this work? */
 		foreach(SubDevice& sub, devices) {
+			int sy = y + i*sub_h;
+			int sh = (i == (int)devices.size() - 1)? h - sub_h*i: sub_h;
+
 			mem.device_pointer = sub.ptr_map[tmp];
-			sub.device->mem_copy_from(mem, offset, size);
-			break;
+			sub.device->mem_copy_from(mem, sy, w, sh, elem);
+			i++;
 		}
 
 		mem.device_pointer = tmp;
@@ -332,37 +335,39 @@ Device *device_multi_create(DeviceInfo& info, bool background)
 	return new MultiDevice(info, background);
 }
 
-static void device_multi_add(vector<DeviceInfo>& devices, DeviceType type, bool skip_display, const char *id_fmt, int num)
+static void device_multi_add(vector<DeviceInfo>& devices, DeviceType type, bool with_display, const char *id_fmt, int num)
 {
 	DeviceInfo info;
 
 	/* create map to find duplicate descriptions */
 	map<string, int> dupli_map;
 	map<string, int>::iterator dt;
-	int num_added = 0, num_skipped = 0;
+	int num_added = 0, num_display = 0;
 
 	foreach(DeviceInfo& subinfo, devices) {
 		if(subinfo.type == type) {
-			if(skip_display && subinfo.display_device) {
-				num_skipped++;
+			if(subinfo.display_device) {
+				if(with_display)
+					num_display++;
+				else
+					continue;
 			}
-			else {
-				string key = subinfo.description;
 
-				if(dupli_map.find(key) == dupli_map.end())
-					dupli_map[key] = 1;
-				else
-					dupli_map[key]++;
+			string key = subinfo.description;
 
-				info.multi_devices.push_back(subinfo);
-				if(subinfo.display_device)
-					info.display_device = true;
-				num_added++;
-			}
+			if(dupli_map.find(key) == dupli_map.end())
+				dupli_map[key] = 1;
+			else
+				dupli_map[key]++;
+
+			info.multi_devices.push_back(subinfo);
+			if(subinfo.display_device)
+				info.display_device = true;
+			num_added++;
 		}
 	}
 
-	if(num_added <= 1 || (skip_display && num_skipped == 0))
+	if(num_added <= 1 || (with_display && num_display == 0))
 		return;
 
 	/* generate string */
@@ -410,20 +415,24 @@ static void device_multi_add(vector<DeviceInfo>& devices, DeviceType type, bool
 	info.type = DEVICE_MULTI;
 	info.description = desc.str();
 	info.id = string_printf(id_fmt, num);
+	info.display_device = with_display;
 	info.num = 0;
 
-	devices.push_back(info);
+	if(with_display)
+		devices.push_back(info);
+	else
+		devices.insert(devices.begin(), info);
 }
 
 void device_multi_info(vector<DeviceInfo>& devices)
 {
 	int num = 0;
-	device_multi_add(devices, DEVICE_CUDA, true, "CUDA_MULTI_%d", num++);
 	device_multi_add(devices, DEVICE_CUDA, false, "CUDA_MULTI_%d", num++);
+	device_multi_add(devices, DEVICE_CUDA, true, "CUDA_MULTI_%d", num++);
 
 	num = 0;
-	device_multi_add(devices, DEVICE_OPENCL, true, "OPENCL_MULTI_%d", num++);
 	device_multi_add(devices, DEVICE_OPENCL, false, "OPENCL_MULTI_%d", num++);
+	device_multi_add(devices, DEVICE_OPENCL, true, "OPENCL_MULTI_%d", num++);
 }
 
 CCL_NAMESPACE_END