Ongoing #133 improvements

applications/reconstruct/src/ilw/ilw.cu

@@ -8,10 +8,10 @@ using ftl::rgbd::Camera;
 #define T_PER_BLOCK 8
 #define FULL_MASK 0xffffffff
 
-__device__ inline float warpMax(float e) {
+__device__ inline float warpMin(float e) {
 	for (int i = WARP_SIZE/2; i > 0; i /= 2) {
 		const float other = __shfl_xor_sync(FULL_MASK, e, i, WARP_SIZE);
-		e = max(e, other);
+		e = min(e, other);
 	}
 	return e;
 }
@@ -39,8 +39,8 @@ __global__ void correspondence_energy_vector_kernel(
     const float3 camPos2 = pose2 * world1;
     const uint2 screen2 = cam2.camToScreen<uint2>(camPos2);
     
-    float bestconf = 0.0f;
-    float nextbest = 0.0f;
+    float bestcost = 1.1f;
+    float nextbest = 1.0f;
     float3 bestpoint;
 
     // Project to p2 using cam2
@@ -54,29 +54,28 @@ __global__ void correspondence_energy_vector_kernel(
 		if (world2.x == MINF) continue;
 
         // Determine degree of correspondence
-        const float l = length(world1 - world2);
-        const float confidence = ftl::cuda::spatialWeighting(l, 0.04f);
+        const float cost = 1.0f - ftl::cuda::spatialWeighting(world1, world2, 0.04f);
 
-        if (confidence > bestconf) {
+        if (cost < bestcost) {
             bestpoint = world2;
-            nextbest = bestconf;
-            bestconf = confidence;
+            nextbest = bestcost;
+            bestcost = cost;
         }
     }
 
-    const float maxconf = warpMax(bestconf);
-    bool best = maxconf == bestconf;
-    bestconf = (best) ? 0.0f : bestconf;
-    const float conf = maxconf - warpMax(bestconf);
+    const float mincost = warpMin(bestcost);
+    bool best = mincost == bestcost;
+    bestcost = (best) ? nextbest : bestcost;
+    const float confidence = mincost / warpMin(bestcost);
 
-    if (best && maxconf > 0.0f) {
+    if (best && mincost < 1.0f) {
         vout(x,y) = vout.tex2D(x, y) + make_float4(
             (bestpoint.x - world1.x),
             (bestpoint.y - world1.y),
             (bestpoint.z - world1.z),
-            maxconf);
-        eout(x,y) = conf * 5.0f; //maxconf * 5.0f; //(maxconf - warpMax(nextbest));
-    } else if (maxconf == 0.0f && lane == 0) {
+            mincost);
+        eout(x,y) = mincost * 5.0f; //confidence * 5.0f;
+    } else if (mincost >= 1.0f && lane == 0) {
         vout(x,y) = make_float4(0.0f);
         eout(x,y) = 0.0f;
     }