1 files changed, 467 insertions, 0 deletions
diff --git a/dev/MinGfx/src/graphics_app.cc b/dev/MinGfx/src/graphics_app.cc
new file mode 100644
index 0000000..57405f5
--- /dev/null
+++ b/dev/MinGfx/src/graphics_app.cc
@@ -0,0 +1,467 @@
+/*
+ Copyright (c) 2017,2018 Regents of the University of Minnesota.
+ All Rights Reserved.
+ See corresponding header file for details.
+ */
+
+#include "graphics_app.h"
+
+
+namespace mingfx {
+
+
+
+GraphicsApp::GraphicsApp(int width, int height, const std::string &caption) :
+    graphicsInitialized_(false), width_(width), height_(height), caption_(caption), lastDrawT_(0.0),
+    leftDown_(false), middleDown_(false), rightDown_(false), screen_(NULL), window_(NULL)
+{
+}
+
+GraphicsApp::~GraphicsApp() {
+}
+
+void GraphicsApp::InitGraphicsContext() {
+    
+    glfwInit();
+    
+    glfwSetTime(0);
+    
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+    glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
+    glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+    glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+    
+    glfwWindowHint(GLFW_SAMPLES, 0);
+    glfwWindowHint(GLFW_RED_BITS, 8);
+    glfwWindowHint(GLFW_GREEN_BITS, 8);
+    glfwWindowHint(GLFW_BLUE_BITS, 8);
+    glfwWindowHint(GLFW_ALPHA_BITS, 8);
+    glfwWindowHint(GLFW_STENCIL_BITS, 8);
+    glfwWindowHint(GLFW_DEPTH_BITS, 24);
+    glfwWindowHint(GLFW_RESIZABLE, GL_TRUE);
+    
+    
+    // on OSX, glfwCreateWindow bombs if we pass caption_.c_str() in for the 3rd
+    // parameter perhaps because it's const.  so, copying to a tmp char array here.
+    char *title = new char[caption_.size() + 1];
+    for (int i = 0; i < caption_.size(); i++) {
+        title[i] = caption_[i];
+    }
+    title[caption_.size()] = '\0';
+    std::cout << caption_ << std::endl;
+    
+    // Create a GLFWwindow object
+    window_ = glfwCreateWindow(width_, height_, title, NULL, NULL);
+    if (window_ == nullptr) {
+        std::cerr << "Failed to create GLFW window" << std::endl;
+        glfwTerminate();
+        exit(-1);
+    }
+    glfwMakeContextCurrent(window_);
+    glfwSetWindowUserPointer(window_, this);
+
+    // cleanup tmp title hack
+    delete [] title;
+    
+    
+#if defined(NANOGUI_GLAD)
+    if (!gladLoadGLLoader((GLADloadproc) glfwGetProcAddress))
+       throw std::runtime_error("Could not initialize GLAD!");
+    glGetError(); // pull and ignore unhandled errors like GL_INVALID_ENUM
+#endif
+    
+    glClearColor(0.2f, 0.25f, 0.3f, 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+    
+    // Create a nanogui screen and pass the glfw pointer to initialize
+    screen_ = new nanogui::Screen();
+    screen_->initialize(window_, true);
+    
+    glfwGetFramebufferSize(window_, &width_, &height_);
+    glViewport(0, 0, width_, height_);
+    glfwSwapInterval(0);
+    glfwSwapBuffers(window_);
+    
+    screen_->setVisible(true);
+    screen_->performLayout();
+
+    glfwSetCursorPosCallback(window_,
+        [](GLFWwindow *window, double x, double y) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+             app->cursor_pos_glfw_cb(x, y);
+         }
+    );
+
+    glfwSetMouseButtonCallback(window_,
+        [](GLFWwindow *window, int button, int action, int modifiers) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+            app->mouse_button_glfw_cb(button, action, modifiers);
+        }
+    );
+
+    glfwSetKeyCallback(window_,
+        [](GLFWwindow *window, int key, int scancode, int action, int mods) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+             app->key_glfw_cb(key, scancode, action, mods);
+        }
+    );
+
+    glfwSetCharCallback(window_,
+        [](GLFWwindow *window, unsigned int codepoint) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+            app->char_glfw_cb(codepoint);
+        }
+    );
+
+    glfwSetDropCallback(window_,
+        [](GLFWwindow *window, int count, const char **filenames) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+            app->drop_glfw_cb(count, filenames);
+        }
+    );
+
+    glfwSetScrollCallback(window_,
+        [](GLFWwindow *window, double x, double y) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+            app->scroll_glfw_cb(x, y);
+        }
+    );
+
+    glfwSetFramebufferSizeCallback(window_,
+        [](GLFWwindow *window, int width, int height) {
+            GraphicsApp *app = (GraphicsApp*)glfwGetWindowUserPointer(window);
+            app->resize_glfw_cb(width, height);
+        }
+    );
+
+    graphicsInitialized_ = true;
+ }
+
+
+    
+void GraphicsApp::Run() {
+
+    if (!graphicsInitialized_) {
+        InitGraphicsContext();        
+    }
+
+    InitNanoGUI();
+
+    InitOpenGL();
+    
+    // Main program loop
+    glfwSetTime(0.0);
+    while (!glfwWindowShouldClose(window_)) {
+
+        // Poll for new user input events and call callbacks
+        glfwPollEvents();
+
+        // Update the simulation, i.e., perform all non-graphics updates that
+        // should happen each frame.
+        double now = glfwGetTime();
+        UpdateSimulation(now-lastDrawT_);
+        lastDrawT_ = now;
+        
+        // Clear is handled in this mainloop so that drawing works even for
+        // users who do not want to fill in DrawUsingOpenGL()
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
+
+        // NanoGUI sets these to something other than the OpenGL defaults, which
+        // screws up most OpenGL programs, so we need to reset them each frame here.
+        glEnable(GL_CULL_FACE);
+        glCullFace(GL_BACK);
+        glEnable(GL_DEPTH_TEST);
+        
+        // Users may fill this in to do raw OpenGL rendering
+        DrawUsingOpenGL();
+
+        // This renders the nanogui widgets created on screen_
+        screen_->drawContents();
+        screen_->drawWidgets();
+        
+        // Users may fill this in to do additional 2D rendering with the NanoVG library
+        DrawUsingNanoVG(screen_->nvgContext());
+        
+        glfwSwapBuffers(window_);
+    }
+    
+    glfwTerminate();
+}
+    
+
+
+bool GraphicsApp::cursor_pos_glfw_cb(double x, double y) {
+    
+    if (screen_->cursorPosCallbackEvent(x,y)) {
+        // event was handled by nanogui
+        lastMouse_ = Point2((float)x, (float)y);
+        return true;
+    }
+    else {
+        Point2 cur((float)x, (float)y);
+        Vector2 delta = cur - lastMouse_;
+
+        // if no buttons are down, generate a mouse move event
+        if (!leftDown_ && !middleDown_ && !rightDown_) {
+            mouse_move(cur, delta);
+        }
+        
+        // if a button is down, generate a corresponding mouse drag event
+        if (leftDown_) {
+            left_mouse_drag(cur, delta);
+        }
+        if (middleDown_) {
+            middle_mouse_drag(cur, delta);
+        }
+        if (rightDown_) {
+            right_mouse_drag(cur, delta);
+        }
+        
+        lastMouse_ = cur;
+        return false;
+    }
+}
+
+bool GraphicsApp::mouse_button_glfw_cb(int button, int action, int modifiers) {
+    if (screen_->mouseButtonCallbackEvent(button, action, modifiers)) {
+        return true;
+    }
+    else if (button == GLFW_MOUSE_BUTTON_LEFT) {
+        double x,y;
+        glfwGetCursorPos(window_, &x, &y);
+        if (action == 1) {
+            left_mouse_down(Point2((float)x, (float)y));
+            leftDown_ = true;
+        }
+        else {
+            left_mouse_up(Point2((float)x, (float)y));
+            leftDown_ = false;
+        }
+        return true;
+    }
+    else if (button == GLFW_MOUSE_BUTTON_MIDDLE) {
+        double x,y;
+        glfwGetCursorPos(window_, &x, &y);
+        if (action == 1) {
+            middle_mouse_down(Point2((float)x, (float)y));
+            middleDown_ = true;
+        }
+        else {
+            middle_mouse_up(Point2((float)x, (float)y));
+            middleDown_ = false;
+        }
+        return true;
+    }
+    else if (button == GLFW_MOUSE_BUTTON_RIGHT) {
+        double x,y;
+        glfwGetCursorPos(window_, &x, &y);
+        if (action == 1) {
+            right_mouse_down(Point2((float)x, (float)y));
+            rightDown_ = true;
+        }
+        else {
+            right_mouse_up(Point2((float)x, (float)y));
+            rightDown_ = false;
+        }
+        return true;
+    }
+    return false;
+}
+
+
+bool GraphicsApp::key_glfw_cb(int key, int scancode, int action, int modifiers) {
+    if (screen_->keyCallbackEvent(key, scancode, action, modifiers)) {
+        return true;
+    }
+    else {
+    if (glfwGetKeyName(key, scancode) != NULL) {
+        if (action == GLFW_PRESS) {
+            key_down(glfwGetKeyName(key, scancode), modifiers);
+        }
+        else if (action == GLFW_REPEAT) {
+            key_repeat(glfwGetKeyName(key, scancode), modifiers);
+        }
+        else {
+            key_up(glfwGetKeyName(key, scancode), modifiers);
+        }
+        return true;
+    }
+    else {
+        if (action == GLFW_PRESS) {
+            special_key_down(key, scancode, modifiers);
+        }
+        else if (action == GLFW_REPEAT) {
+            special_key_repeat(key, scancode, modifiers);
+        }
+        else {
+            special_key_up(key, scancode, modifiers);
+        }
+        return true;
+    }
+    }
+
+    return false;
+}
+
+
+bool GraphicsApp::char_glfw_cb(unsigned int codepoint) {
+    if (screen_->charCallbackEvent(codepoint)) {
+        return true;
+    }
+    else {
+        // TODO: could add another virtual function to GraphicsApp to
+        // respond to this if needed
+    }
+    return false;
+}
+
+
+bool GraphicsApp::drop_glfw_cb(int count, const char **filenames) {
+    if (screen_->dropCallbackEvent(count, filenames)) {
+        return true;
+    }
+    else {
+        // TODO: could add another virtual function to GraphicsApp to
+        // respond to this if needed
+    }
+    return false;
+}
+
+
+bool GraphicsApp::scroll_glfw_cb(double x, double y) {
+    if (screen_->scrollCallbackEvent(x,y)) {
+        return true;
+    }
+    else {
+        // TODO: could add another virtual function to GraphicsApp to
+        // respond to this if needed
+    }
+    return false;
+}
+
+
+bool GraphicsApp::resize_glfw_cb(int width, int height) {
+    if (screen_->resizeCallbackEvent(width, height)) {
+        return true;
+    }
+    else {
+        // the width and height reported here are the new framebuffer size
+        // we will query/save/report the new window size instead
+        width_ = window_width();
+        height_ = window_height();
+        OnWindowResize(width_, height_);
+    }
+    return false;
+}
+
+
+bool GraphicsApp::IsKeyDown(int key) {
+    return (glfwGetKey(window_, key) == GLFW_PRESS);
+}
+
+bool GraphicsApp::IsLeftMouseDown() {
+    return (glfwGetMouseButton(window_, GLFW_MOUSE_BUTTON_LEFT) == GLFW_PRESS);
+}
+
+
+bool GraphicsApp::IsMiddleMouseDown() {
+    return (glfwGetMouseButton(window_, GLFW_MOUSE_BUTTON_MIDDLE) == GLFW_PRESS);
+}
+
+
+bool GraphicsApp::IsRightMouseDown() {
+    return (glfwGetMouseButton(window_, GLFW_MOUSE_BUTTON_RIGHT) == GLFW_PRESS);
+}
+
+    
+
+float GraphicsApp::aspect_ratio() {
+    int width, height;
+    glfwGetFramebufferSize(window_, &width, &height);
+    return (float)width/(float)height;
+}
+    
+int GraphicsApp::window_width() {
+    int width, height;
+    glfwGetWindowSize(window_, &width, &height);
+    return width;
+}
+
+int GraphicsApp::framebuffer_width() {
+    int width, height;
+    glfwGetFramebufferSize(window_, &width, &height);
+    return width;
+}
+
+int GraphicsApp::window_height() {
+    int width, height;
+    glfwGetWindowSize(window_, &width, &height);
+    return height;
+}
+
+int GraphicsApp::framebuffer_height() {
+    int width, height;
+    glfwGetFramebufferSize(window_, &width, &height);
+    return height;
+}
+    
+Point2 GraphicsApp::PixelsToNormalizedDeviceCoords(const Point2 &pointInPixels) {
+    float x = (pointInPixels[0] / window_width()) * 2.0f - 1.0f;
+    float y = (1.0f - (pointInPixels[1] / window_height())) * 2.0f - 1.0f;
+    return Point2(x,y);
+}
+
+Point2 GraphicsApp::NormalizedDeviceCoordsToPixels(const Point2 &pointInNDC) {
+    float x = 0.5f * (pointInNDC[0] + 1.0f) * window_width();
+    float y = (1.0f - (0.5f * (pointInNDC[1] + 1.0f))) * window_height();
+    return Point2(x,y);
+}
+
+Vector2 GraphicsApp::PixelsToNormalizedDeviceCoords(const Vector2 &vectorInPixels) {
+    float x = (2.0f/window_width()) * vectorInPixels[0];
+    float y = (-2.0f/window_height()) * vectorInPixels[1];
+    return Vector2(x,y);
+}
+
+Vector2 GraphicsApp::NormalizedDeviceCoordsToPixels(const Vector2 &vectorInNDC) {
+    float x = (window_width()/2.0f) * vectorInNDC[0];
+    float y = (-window_height()/2.0f) * vectorInNDC[1];
+    return Vector2(x,y);
+}
+
+float GraphicsApp::ReadZValueAtPixel(const Point2 &pointInPixels, unsigned int whichBuffer) {
+    // scale screen points to framebuffer size, since they are not the same on retina displays
+    float x01 = pointInPixels[0] / window_width();
+    float y01 = pointInPixels[1] / window_height();
+    y01 = 1.0f - y01;
+    
+    float x = x01 * (float)framebuffer_width();
+    float y = y01 * (float)framebuffer_height();
+
+    float z;
+    glReadPixels((int)x, (int)y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &z);
+    return z;
+}
+    
+    
+nanogui::Screen* GraphicsApp::screen() {
+    return screen_;
+}
+
+GLFWwindow* GraphicsApp::window() {
+    return window_;
+}
+    
+    
+void GraphicsApp::ResizeWindow(int new_width, int new_height) {
+    glfwSetWindowSize(window_, new_width, new_height);
+    width_ = new_width;
+    height_ = new_height;
+    OnWindowResize(new_width, new_height);
+}
+
+    
+    
+
+
+} // end namespace