OpenGL Rendering

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Original author	Amir Hassan (kallaballa) amir@.nosp@m.viel.nosp@m.-zu.o.nosp@m.rg
Compatibility	OpenCV >= 4.7

Render a blue screen using OpenGL

This example simply paints the screen blue using OpenGL without shaders for brevity. One important detail of this example is that states are being preserved between invocations of a context type (in this case the gl context).

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#include <opencv2/v4d/v4d.hpp>
 
using namespace cv;
using namespace cv::v4d;
 
class RenderOpenGLPlan : public Plan {
public:
    void setup(Ptr<V4D> win) override {
        win->gl([]() {
            //Sets the clear color to blue
            glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
        });
    }
    void infer(Ptr<V4D> win) override {
        win->gl([]() {
            //Clears the screen. The clear color and other GL-states are preserved between context-calls.
            glClear(GL_COLOR_BUFFER_BIT);
        });
    }
};
 
int main() {
    Ptr<V4D> window = V4D::make(960, 960, "GL Blue Screen");
    window->run<RenderOpenGLPlan>(0);
}