Method on_draw

samples/gl-render-texture/gl-render-texture.cpp:167–219

}

void sample_gl_render_offscreen::on_draw()
{
    glfwMakeContextCurrent(window);

    int width, height;
    glfwGetWindowSize(window, &width, &height);

    glEnable(GL_CULL_FACE);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    // Render to framebuffer
    {
        glBindFramebuffer(GL_FRAMEBUFFER, renderFramebuffer);
        glViewport(0, 0, width, height);
        glClearColor(0.25f, 0.25f, 0.25f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        const float4x4 projectionMatrix = cam.get_projection_matrix(float(width) / float(height));
        const float4x4 viewMatrix = cam.get_view_matrix();
        const float4x4 viewProjectionMatrix = projectionMatrix * viewMatrix;

        auto default_wireframe_variant = wireframe_handle.get()->get_variant();
        auto & wireframe_prog = default_wireframe_variant->shader;

        wireframe_prog.bind();
        for (auto & object : objects)
        {
            const float4x4 modelMatrix = object.t.matrix() * make_scaling_matrix(object.scale);
            wireframe_prog.uniform("u_color", selected_object == &object ? float4(1, 0, 0, 0.5f) : float4(1, 1, 1, 0.5));
            wireframe_prog.uniform("u_eyePos", cam.get_eye_point());
            wireframe_prog.uniform("u_viewProjMatrix", viewProjectionMatrix);
            wireframe_prog.uniform("u_modelMatrix", modelMatrix);
            object.mesh.draw_elements();
        }
        wireframe_prog.unbind();

        grid.draw(viewMatrix, projectionMatrix, cam.get_eye_point());
    }

    // Render to default framebuffer (the screen)
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glViewport(0, 0, width, height);
    glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    view->draw(renderTextureRGBA);

    gl_check_error(__FILE__, __LINE__);

    glfwSwapBuffers(window); 
}

int main(int argc, char * argv[])
{