// This file is part of OpenCV project. // It is subject to the license terms in the LICENSE file found in the top-level directory // of this distribution and at http://opencv.org/license.html. // Copyright Amir Hassan (kallaballa) #include //adapted from https://gitlab.com/wikibooks-opengl/modern-tutorials/-/blob/master/tut05_cube/cube.cpp /* Demo Parameters */ #ifndef __EMSCRIPTEN__ constexpr long unsigned int WIDTH = 1280; constexpr long unsigned int HEIGHT = 720; #else constexpr size_t NUMBER_OF_CUBES = 5; constexpr long unsigned int WIDTH = 960; constexpr long unsigned int HEIGHT = 960; #endif constexpr bool OFFSCREEN = false; #ifndef __EMSCRIPTEN__ constexpr double FPS = 60; constexpr const char* OUTPUT_FILENAME = "many_cubes-demo.mkv"; #endif const unsigned long DIAG = hypot(double(WIDTH), double(HEIGHT)); const int glow_kernel_size = std::max(int(DIAG / 138 % 2 == 0 ? DIAG / 138 + 1 : DIAG / 138), 1); using std::cerr; using std::endl; /* OpenGL constants and variables */ const GLuint triangles = 12; const GLuint vertices_index = 0; const GLuint colors_index = 1; //Cube vertices, colors and indices const float vertices[] = { // Front face 0.5, 0.5, 0.5, -0.5, 0.5, 0.5, -0.5, -0.5, 0.5, 0.5, -0.5, 0.5, // Back face 0.5, 0.5, -0.5, -0.5, 0.5, -0.5, -0.5, -0.5, -0.5, 0.5, -0.5, -0.5 }; const float vertex_colors[] = { 1.0, 0.4, 0.6, 1.0, 0.9, 0.2, 0.7, 0.3, 0.8, 0.5, 0.3, 1.0, 0.2, 0.6, 1.0, 0.6, 1.0, 0.4, 0.6, 0.8, 0.8, 0.4, 0.8, 0.8 }; const unsigned short triangle_indices[] = { // Front 0, 1, 2, 2, 3, 0, // Right 0, 3, 7, 7, 4, 0, // Bottom 2, 6, 7, 7, 3, 2, // Left 1, 5, 6, 6, 2, 1, // Back 4, 7, 6, 6, 5, 4, // Top 5, 1, 0, 0, 4, 5 }; //Simple transform & pass-through shaders static GLuint load_shader() { //Shader versions "330" and "300 es" are very similar. //If you are careful you can write the same code for both versions. #if !defined(__EMSCRIPTEN__) && !defined(OPENCV_V4D_USE_ES3) const string shaderVersion = "330"; #else const string shaderVersion = "300 es"; #endif const string vert = " #version " + shaderVersion + R"( precision lowp float; layout(location = 0) in vec3 pos; layout(location = 1) in vec3 vertex_color; uniform mat4 transform; out vec3 color; void main() { gl_Position = transform * vec4(pos, 1.0); color = vertex_color; } )"; const string frag = " #version " + shaderVersion + R"( precision lowp float; in vec3 color; out vec4 frag_color; void main() { frag_color = vec4(color, 1.0); } )"; //Initialize the shaders and returns the program return cv::v4d::initShader(vert.c_str(), frag.c_str(), "fragColor"); } //Initializes objects, buffers, shaders and uniforms static void init_scene(const cv::Size& sz, GLuint& vao, GLuint& shaderProgram, GLuint& uniformTransform) { glEnable (GL_DEPTH_TEST); glGenVertexArrays(1, &vao); glBindVertexArray(vao); unsigned int triangles_ebo; glGenBuffers(1, &triangles_ebo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, triangles_ebo); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof triangle_indices, triangle_indices, GL_STATIC_DRAW); unsigned int verticies_vbo; glGenBuffers(1, &verticies_vbo); glBindBuffer(GL_ARRAY_BUFFER, verticies_vbo); glBufferData(GL_ARRAY_BUFFER, sizeof vertices, vertices, GL_STATIC_DRAW); glVertexAttribPointer(vertices_index, 3, GL_FLOAT, GL_FALSE, 0, NULL); glEnableVertexAttribArray(vertices_index); unsigned int colors_vbo; glGenBuffers(1, &colors_vbo); glBindBuffer(GL_ARRAY_BUFFER, colors_vbo); glBufferData(GL_ARRAY_BUFFER, sizeof vertex_colors, vertex_colors, GL_STATIC_DRAW); glVertexAttribPointer(colors_index, 3, GL_FLOAT, GL_FALSE, 0, NULL); glEnableVertexAttribArray(colors_index); glBindVertexArray(0); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0); glBindBuffer(GL_ARRAY_BUFFER, 0); shaderProgram = load_shader(); uniformTransform = glGetUniformLocation(shaderProgram, "transform"); glViewport(0,0, sz.width, sz.height); } //Renders a rotating rainbow-colored cube on a blueish background static void render_scene(GLuint &vao, GLuint &shaderProgram, GLuint &uniformTransform) { //Clear the background glClearColor(0.2, 0.24, 0.4, 1); glClear(GL_COLOR_BUFFER_BIT); //Use the prepared shader program glUseProgram(shaderProgram); //Scale and rotate the cube depending on the current time. float angle = fmod( double(cv::getTickCount()) / double(cv::getTickFrequency()), 2 * M_PI); float scale = 0.25; cv::Matx44f scaleMat(scale, 0.0, 0.0, 0.0, 0.0, scale, 0.0, 0.0, 0.0, 0.0, scale, 0.0, 0.0, 0.0, 0.0, 1.0); cv::Matx44f rotXMat(1.0, 0.0, 0.0, 0.0, 0.0, cos(angle), -sin(angle), 0.0, 0.0, sin(angle), cos(angle), 0.0, 0.0, 0.0, 0.0, 1.0); cv::Matx44f rotYMat(cos(angle), 0.0, sin(angle), 0.0, 0.0, 1.0, 0.0, 0.0, -sin(angle), 0.0, cos(angle), 0.0, 0.0, 0.0, 0.0, 1.0); cv::Matx44f rotZMat(cos(angle), -sin(angle), 0.0, 0.0, sin(angle), cos(angle), 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0); //calculate the transform cv::Matx44f transform = scaleMat * rotXMat * rotYMat * rotZMat; //set the corresponding uniform glUniformMatrix4fv(uniformTransform, 1, GL_FALSE, transform.val); //Bind the prepared vertex array object glBindVertexArray(vao); //Draw glDrawElements(GL_TRIANGLES, triangles * 3, GL_UNSIGNED_SHORT, NULL); } //applies a glow effect to an image static void glow_effect(const cv::UMat& src, cv::UMat& dst, const int ksize) { thread_local cv::UMat resize; thread_local cv::UMat blur; thread_local cv::UMat dst16; cv::bitwise_not(src, dst); //Resize for some extra performance cv::resize(dst, resize, cv::Size(), 0.5, 0.5); //Cheap blur cv::boxFilter(resize, resize, -1, cv::Size(ksize, ksize), cv::Point(-1, -1), true, cv::BORDER_REPLICATE); //Back to original size cv::resize(resize, blur, src.size()); //Multiply the src image with a blurred version of itself cv::multiply(dst, blur, dst16, 1, CV_16U); //Normalize and convert back to CV_8U cv::divide(dst16, cv::Scalar::all(255.0), dst, 1, CV_8U); cv::bitwise_not(dst, dst); } using namespace cv::v4d; class CubeDemoPlan : public Plan { cv::UMat frame_; GLuint vao; GLuint shaderProgram; GLuint uniformTransform; public: void setup(cv::Ptr window) { window->gl([](const cv::Size& sz, GLuint& v, GLuint& sp, GLuint& ut){ init_scene(sz, v, sp, ut); }, window->fbSize(), vao, shaderProgram, uniformTransform); } void infer(cv::Ptr window) { window->gl([](){ //Clear the background glClearColor(0.2, 0.24, 0.4, 1); glClear(GL_COLOR_BUFFER_BIT); }); //Render using multiple OpenGL contexts window->gl([](GLuint& v, GLuint& sp, GLuint& ut){ render_scene(v, sp, ut); }, vao, shaderProgram, uniformTransform); //Aquire the frame buffer for use by OpenCV window->fb([](cv::UMat& framebuffer, cv::UMat& f) { glow_effect(framebuffer, framebuffer, glow_kernel_size); framebuffer.copyTo(f); }, frame_); window->write([](cv::UMat& outputFrame, const cv::UMat& f){ f.copyTo(outputFrame); }, frame_); } }; int main() { cv::Ptr window = V4D::make(WIDTH, HEIGHT, "Many Cubes Demo", IMGUI, OFFSCREEN); window->printSystemInfo(); #ifndef __EMSCRIPTEN__ //Creates a writer sink (which might be hardware accelerated) auto sink = makeWriterSink(window, OUTPUT_FILENAME, FPS, cv::Size(WIDTH, HEIGHT)); window->setSink(sink); #endif window->run(0); return 0; }