Merge pull request #15699 from TolyaTalamanov:at/graph-ocv-render-backend-skeleton

G-API: Implement OpenCV render backend

* Implement render opencv backend

* Fix comment to review

* Add comment

* Add wrappers for kernels

* Fix comments to review

* Fix comment to review

modules/gapi/src/api/render.cpp

@@ -1,34 +1,33 @@
 #include <opencv2/imgproc.hpp>
-#include <opencv2/gapi/render.hpp>
+#include <opencv2/gapi/render/render.hpp>
 #include <opencv2/gapi/own/assert.hpp>
 
 #include "api/render_priv.hpp"
 
 void cv::gapi::wip::draw::render(cv::Mat &bgr,
                                  const cv::gapi::wip::draw::Prims &prims,
-                                 const cv::gapi::GKernelPackage& pkg)
+                                 cv::GCompileArgs&& args)
 {
     cv::GMat in;
     cv::GArray<Prim> arr;
 
     cv::GComputation comp(cv::GIn(in, arr),
-                          cv::GOut(cv::gapi::wip::draw::GRenderBGR::on(in, arr)));
-    comp.apply(cv::gin(bgr, prims), cv::gout(bgr), cv::compile_args(pkg));
+                          cv::GOut(cv::gapi::wip::draw::render3ch(in, arr)));
+    comp.apply(cv::gin(bgr, prims), cv::gout(bgr), std::move(args));
 }
 
 void cv::gapi::wip::draw::render(cv::Mat &y_plane,
                                  cv::Mat &uv_plane,
                                  const Prims &prims,
-                                 const GKernelPackage& pkg)
+                                 cv::GCompileArgs&& args)
 {
     cv::GMat y_in, uv_in, y_out, uv_out;
     cv::GArray<Prim> arr;
-    std::tie(y_out, uv_out) = cv::gapi::wip::draw::GRenderNV12::on(y_in, uv_in, arr);
+    std::tie(y_out, uv_out) = cv::gapi::wip::draw::renderNV12(y_in, uv_in, arr);
 
     cv::GComputation comp(cv::GIn(y_in, uv_in, arr), cv::GOut(y_out, uv_out));
     comp.apply(cv::gin(y_plane, uv_plane, prims),
-               cv::gout(y_plane, uv_plane),
-               cv::compile_args(pkg));
+               cv::gout(y_plane, uv_plane), std::move(args));
 }
 
 void cv::gapi::wip::draw::BGR2NV12(const cv::Mat &bgr,
@@ -48,3 +47,28 @@ void cv::gapi::wip::draw::BGR2NV12(const cv::Mat &bgr,
     cv::merge(std::vector<cv::Mat>{chs[1], chs[2]}, uv_plane);
     cv::resize(uv_plane, uv_plane, uv_plane.size() / 2, cv::INTER_LINEAR);
 }
+
+namespace cv
+{
+namespace detail
+{
+    template<> struct CompileArgTag<cv::gapi::wip::draw::use_freetype>
+    {
+        static const char* tag() { return "gapi.use_freetype"; }
+    };
+
+} // namespace detail
+
+GMat cv::gapi::wip::draw::render3ch(const GMat& src, const GArray<Prim>& prims)
+{
+    return cv::gapi::wip::draw::GRenderBGR::on(src, prims);
+}
+
+std::tuple<GMat, GMat> cv::gapi::wip::draw::renderNV12(const GMat& y,
+                                                       const GMat& uv,
+                                                       const GArray<cv::gapi::wip::draw::Prim>& prims)
+{
+    return cv::gapi::wip::draw::GRenderNV12::on(y, uv, prims);
+}
+
+} // namespace cv

modules/gapi/src/api/render_ocv.cpp

@@ -1,6 +1,5 @@
-#include <opencv2/gapi/cpu/gcpukernel.hpp>
 #include <opencv2/imgproc.hpp>
-#include <opencv2/gapi/render.hpp> // Kernel API's
+#include <opencv2/gapi/render/render.hpp> // Kernel API's
 
 #include "api/render_ocv.hpp"
 
@@ -11,61 +10,6 @@ namespace gapi
 
 namespace ocv
 {
-
-GAPI_OCV_KERNEL(GOCVRenderNV12, cv::gapi::wip::draw::GRenderNV12)
-{
-    static void run(const cv::Mat& y, const cv::Mat& uv, const cv::gapi::wip::draw::Prims& prims,
-                    cv::Mat& out_y, cv::Mat& out_uv)
-    {
-        /* FIXME How to render correctly on NV12 format ?
-         *
-         * Rendering on NV12 via OpenCV looks like this:
-         *
-         * y --------> 1)(NV12 -> YUV) -> yuv -> 2)draw -> yuv -> 3)split -------> out_y
-         *                  ^                                         |
-         *                  |                                         |
-         * uv --------------                                          `----------> out_uv
-         *
-         *
-         * 1) Collect yuv mat from two planes, uv plain in two times less than y plane
-         *    so, upsample uv in tow times, with bilinear interpolation
-         *
-         * 2) Render primitives on YUV
-         *
-         * 3) Convert yuv to NV12 (using bilinear interpolation)
-         *
-         */
-
-        // NV12 -> YUV
-        cv::Mat upsample_uv, yuv;
-        cv::resize(uv, upsample_uv, uv.size() * 2, cv::INTER_LINEAR);
-        cv::merge(std::vector<cv::Mat>{y, upsample_uv}, yuv);
-
-        cv::gapi::wip::draw::drawPrimitivesOCVYUV(yuv, prims);
-
-        // YUV -> NV12
-        cv::Mat out_u, out_v, uv_plane;
-        std::vector<cv::Mat> chs = {out_y, out_u, out_v};
-        cv::split(yuv, chs);
-        cv::merge(std::vector<cv::Mat>{chs[1], chs[2]}, uv_plane);
-        cv::resize(uv_plane, out_uv, uv_plane.size() / 2, cv::INTER_LINEAR);
-    }
-};
-
-GAPI_OCV_KERNEL(GOCVRenderBGR, cv::gapi::wip::draw::GRenderBGR)
-{
-    static void run(const cv::Mat&, const cv::gapi::wip::draw::Prims& prims, cv::Mat& out)
-    {
-        cv::gapi::wip::draw::drawPrimitivesOCVBGR(out, prims);
-    }
-};
-
-cv::gapi::GKernelPackage kernels()
-{
-    static const auto pkg = cv::gapi::kernels<GOCVRenderNV12, GOCVRenderBGR>();
-    return pkg;
-}
-
 } // namespace ocv
 
 namespace wip

modules/gapi/src/api/render_priv.hpp

@@ -8,7 +8,7 @@
 #ifndef OPENCV_RENDER_PRIV_HPP
 #define OPENCV_RENDER_PRIV_HPP
 
-#include <opencv2/gapi/render.hpp>
+#include <opencv2/gapi/render/render.hpp>
 
 namespace cv
 {