fix OpenGL render functions

fix createOpticalFlowNeedleMap

modules/core/src/opengl_interop.cpp

@@ -1330,7 +1330,7 @@ void cv::render(const GlArrays& arr, int mode, Scalar color)
 #ifndef HAVE_OPENGL
     throw_nogl;
 #else
-    glColor3d(color[0] / 255.0, color[1] / 255.0, color[3] / 255.0);
+    glColor3d(color[0] / 255.0, color[1] / 255.0, color[2] / 255.0);
 
     arr.bind();
 
@@ -1358,9 +1358,10 @@ void cv::render(const string& str, const Ptr<GlFont>& font, Scalar color, Point2
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
 
+    glColor3d(color[0] / 255.0, color[1] / 255.0, color[2] / 255.0);
+
     glRasterPos2d(2.0 * (viewport[0] + pos.x) / viewport[2] - 1.0, 1.0 - 2.0 * (viewport[1] + pos.y + font->height()) / viewport[3]);
 
-    glColor4dv(color.val);
     font->draw(str.c_str(), str.length());
 
     glPopAttrib();

modules/gpu/src/cuda/optical_flow.cu

@@ -47,7 +47,6 @@ namespace cv { namespace gpu { namespace device
     namespace optical_flow
     {
         #define NEEDLE_MAP_SCALE 16
-        #define MAX_FLOW 30.0f
         #define NUM_VERTS_PER_ARROW 6
 
         __global__ void NeedleMapAverageKernel(const DevMem2Df u, const PtrStepf v, PtrStepf u_avg, PtrStepf v_avg)
@@ -123,7 +122,7 @@ namespace cv { namespace gpu { namespace device
             cudaSafeCall( cudaDeviceSynchronize() );
         }
 
-        __global__ void NeedleMapVertexKernel(const DevMem2Df u_avg, const PtrStepf v_avg, float* vertex_data, float* color_data, float xscale, float yscale)
+        __global__ void NeedleMapVertexKernel(const DevMem2Df u_avg, const PtrStepf v_avg, float* vertex_data, float* color_data, float max_flow, float xscale, float yscale)
         {
             // test - just draw a triangle at each pixel
             const int x = blockIdx.x * blockDim.x + threadIdx.x;
@@ -142,7 +141,7 @@ namespace cv { namespace gpu { namespace device
                 const float theta = ::atan2f(v_avg_val, u_avg_val) + CV_PI;
 
                 float r = ::sqrtf(v_avg_val * v_avg_val + u_avg_val * u_avg_val);
-                r = fmin(14.0f * (r / MAX_FLOW), 14.0f);
+                r = fmin(14.0f * (r / max_flow), 14.0f);
 
                 v[0].z = 1.0f;
                 v[1].z = 0.7f;
@@ -203,12 +202,12 @@ namespace cv { namespace gpu { namespace device
             }
         }
 
-        void CreateOpticalFlowNeedleMap_gpu(DevMem2Df u_avg, DevMem2Df v_avg, float* vertex_buffer, float* color_data, float xscale, float yscale)
+        void CreateOpticalFlowNeedleMap_gpu(DevMem2Df u_avg, DevMem2Df v_avg, float* vertex_buffer, float* color_data, float max_flow, float xscale, float yscale)
         {
             const dim3 block(16);
             const dim3 grid(divUp(u_avg.cols, block.x), divUp(u_avg.rows, block.y));
 
-            NeedleMapVertexKernel<<<grid, block>>>(u_avg, v_avg, vertex_buffer, color_data, xscale, yscale);
+            NeedleMapVertexKernel<<<grid, block>>>(u_avg, v_avg, vertex_buffer, color_data, max_flow, xscale, yscale);
             cudaSafeCall( cudaGetLastError() );
 
             cudaSafeCall( cudaDeviceSynchronize() );

modules/gpu/src/optical_flow.cpp

@@ -194,7 +194,7 @@ namespace cv { namespace gpu { namespace device
     namespace optical_flow
     {
         void NeedleMapAverage_gpu(DevMem2Df u, DevMem2Df v, DevMem2Df u_avg, DevMem2Df v_avg);
-        void CreateOpticalFlowNeedleMap_gpu(DevMem2Df u_avg, DevMem2Df v_avg, float* vertex_buffer, float* color_data, float xscale, float yscale);
+        void CreateOpticalFlowNeedleMap_gpu(DevMem2Df u_avg, DevMem2Df v_avg, float* vertex_buffer, float* color_data, float max_flow, float xscale, float yscale);
     }
 }}}
 
@@ -224,7 +224,13 @@ void cv::gpu::createOpticalFlowNeedleMap(const GpuMat& u, const GpuMat& v, GpuMa
 
     colors.setTo(Scalar::all(1.0));
 
-    CreateOpticalFlowNeedleMap_gpu(u_avg, v_avg, vertex.ptr<float>(), colors.ptr<float>(), 1.0f / u.cols, 1.0f / u.rows);
+    double uMax, vMax;
+    minMax(u_avg, 0, &uMax);
+    minMax(v_avg, 0, &vMax);
+
+    float max_flow = static_cast<float>(sqrt(uMax * uMax + vMax * vMax));
+
+    CreateOpticalFlowNeedleMap_gpu(u_avg, v_avg, vertex.ptr<float>(), colors.ptr<float>(), max_flow, 1.0f / u.cols, 1.0f / u.rows);
 
     cvtColor(colors, colors, COLOR_HSV2RGB);
 }