FlutterEmbedderGLFW.cc File Reference

#include <cassert>
#include <chrono>
#include <iostream>
#include "GLFW/glfw3.h"
#include "embedder.h"

Go to the source code of this file.

Functions
void	GLFWcursorPositionCallbackAtPhase (GLFWwindow *window, FlutterPointerPhase phase, double x, double y)
void	GLFWcursorPositionCallback (GLFWwindow *window, double x, double y)
void	GLFWmouseButtonCallback (GLFWwindow *window, int key, int action, int mods)
static void	GLFWKeyCallback (GLFWwindow *window, int key, int scancode, int action, int mods)
void	GLFWwindowSizeCallback (GLFWwindow *window, int width, int height)
bool	RunFlutter (GLFWwindow *window, const std::string &project_path, const std::string &icudtl_path)
void	printUsage ()
void	GLFW_ErrorCallback (int error, const char *description)
int	main (int argc, const char *argv[])

Variables
static double	g_pixelRatio = 1.0
static const size_t	kInitialWindowWidth = 800
static const size_t	kInitialWindowHeight = 600
static constexpr FlutterViewId	kImplicitViewId = 0

Function Documentation

GLFW_ErrorCallback()

void GLFW_ErrorCallback	(	int	error,
		const char *	description
	)

Definition at line 145 of file FlutterEmbedderGLFW.cc.

                                                            {
  std::cout << "GLFW Error: (" << error << ") " << description << std::endl;
}

GLFWcursorPositionCallback()

void GLFWcursorPositionCallback	(	GLFWwindow *	window,
		double	x,
		double	y
	)

Definition at line 45 of file FlutterEmbedderGLFW.cc.

                                                                        {
  GLFWcursorPositionCallbackAtPhase(window, FlutterPointerPhase::kMove, x, y);
}

GLFWcursorPositionCallbackAtPhase()

void GLFWcursorPositionCallbackAtPhase	(	GLFWwindow *	window,
		FlutterPointerPhase	phase,
		double	x,
		double	y
	)

Definition at line 24 of file FlutterEmbedderGLFW.cc.

                                                 {
  FlutterPointerEvent event = {};
  event.struct_size = sizeof(event);
  event.phase = phase;
  event.x = x * g_pixelRatio;
  event.y = y * g_pixelRatio;
  event.timestamp =
      std::chrono::duration_cast<std::chrono::microseconds>(
          std::chrono::high_resolution_clock::now().time_since_epoch())
          .count();
  // This example only supports a single window, therefore we assume the pointer
  // event occurred in the only view, the implicit view.
  event.view_id = kImplicitViewId;
  FlutterEngineSendPointerEvent(
      reinterpret_cast<FlutterEngine>(glfwGetWindowUserPointer(window)), &event,
      1);
}

GLFWKeyCallback()

static void GLFWKeyCallback ( GLFWwindow *  window, int  key, int  scancode, int  action, int  mods  )

static

Definition at line 68 of file FlutterEmbedderGLFW.cc.

                                      {
  if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) {
    glfwSetWindowShouldClose(window, GLFW_TRUE);
  }
}

GLFWmouseButtonCallback()

void GLFWmouseButtonCallback	(	GLFWwindow *	window,
		int	key,
		int	action,
		int	mods
	)

Definition at line 49 of file FlutterEmbedderGLFW.cc.

                                       {
  if (key == GLFW_MOUSE_BUTTON_1 && action == GLFW_PRESS) {
    double x, y;
    glfwGetCursorPos(window, &x, &y);
    GLFWcursorPositionCallbackAtPhase(window, FlutterPointerPhase::kDown, x, y);
    glfwSetCursorPosCallback(window, GLFWcursorPositionCallback);
  }
 
  if (key == GLFW_MOUSE_BUTTON_1 && action == GLFW_RELEASE) {
    double x, y;
    glfwGetCursorPos(window, &x, &y);
    GLFWcursorPositionCallbackAtPhase(window, FlutterPointerPhase::kUp, x, y);
    glfwSetCursorPosCallback(window, nullptr);
  }
}

GLFWwindowSizeCallback()

void GLFWwindowSizeCallback	(	GLFWwindow *	window,
		int	width,
		int	height
	)

Definition at line 78 of file FlutterEmbedderGLFW.cc.

                                                                       {
  FlutterWindowMetricsEvent event = {};
  event.struct_size = sizeof(event);
  event.width = width * g_pixelRatio;
  event.height = height * g_pixelRatio;
  event.pixel_ratio = g_pixelRatio;
  // This example only supports a single window, therefore we assume the event
  // occurred in the only view, the implicit view.
  event.view_id = kImplicitViewId;
  FlutterEngineSendWindowMetricsEvent(
      reinterpret_cast<FlutterEngine>(glfwGetWindowUserPointer(window)),
      &event);
}

main()

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

Definition at line 149 of file FlutterEmbedderGLFW.cc.

                                       {
  if (argc != 3) {
    printUsage();
    return 1;
  }
 
  std::string project_path = argv[1];
  std::string icudtl_path = argv[2];
 
  glfwSetErrorCallback(GLFW_ErrorCallback);
 
  int result = glfwInit();
  if (result != GLFW_TRUE) {
    std::cout << "Could not initialize GLFW." << std::endl;
    return EXIT_FAILURE;
  }
 
#if defined(__linux__)
  glfwWindowHint(GLFW_CONTEXT_CREATION_API, GLFW_EGL_CONTEXT_API);
#endif
 
  GLFWwindow* window = glfwCreateWindow(
      kInitialWindowWidth, kInitialWindowHeight, "Flutter", NULL, NULL);
  if (window == nullptr) {
    std::cout << "Could not create GLFW window." << std::endl;
    return EXIT_FAILURE;
  }
 
  int framebuffer_width, framebuffer_height;
  glfwGetFramebufferSize(window, &framebuffer_width, &framebuffer_height);
  g_pixelRatio = framebuffer_width / kInitialWindowWidth;
 
  bool run_result = RunFlutter(window, project_path, icudtl_path);
  if (!run_result) {
    std::cout << "Could not run the Flutter engine." << std::endl;
    return EXIT_FAILURE;
  }
 
  glfwSetKeyCallback(window, GLFWKeyCallback);
  glfwSetWindowSizeCallback(window, GLFWwindowSizeCallback);
  glfwSetMouseButtonCallback(window, GLFWmouseButtonCallback);
 
  while (!glfwWindowShouldClose(window)) {
    glfwWaitEvents();
  }
 
  glfwDestroyWindow(window);
  glfwTerminate();
 
  return EXIT_SUCCESS;
}

printUsage()

void printUsage

(

)

Definition at line 140 of file FlutterEmbedderGLFW.cc.

                  {
  std::cout << "usage: embedder_example <path to project> <path to icudtl.dat>"
            << std::endl;
}

RunFlutter()

bool RunFlutter	(	GLFWwindow *	window,
		const std::string &	project_path,
		const std::string &	icudtl_path
	)

Definition at line 92 of file FlutterEmbedderGLFW.cc.

                                              {
  FlutterRendererConfig config = {};
  config.type = kOpenGL;
  config.open_gl.struct_size = sizeof(config.open_gl);
  config.open_gl.make_current = [](void* userdata) -> bool {
    glfwMakeContextCurrent(static_cast<GLFWwindow*>(userdata));
    return true;
  };
  config.open_gl.clear_current = [](void*) -> bool {
    glfwMakeContextCurrent(nullptr);  // is this even a thing?
    return true;
  };
  config.open_gl.present = [](void* userdata) -> bool {
    glfwSwapBuffers(static_cast<GLFWwindow*>(userdata));
    return true;
  };
  config.open_gl.fbo_callback = [](void*) -> uint32_t {
    return 0;  // FBO0
  };
  config.open_gl.gl_proc_resolver = [](void*, const char* name) -> void* {
    return reinterpret_cast<void*>(glfwGetProcAddress(name));
  };
 
  // This directory is generated by `flutter build bundle`.
  std::string assets_path = project_path + "/build/flutter_assets";
  FlutterProjectArgs args = {
      .struct_size = sizeof(FlutterProjectArgs),
      .assets_path = assets_path.c_str(),
      .icu_data_path =
          icudtl_path.c_str(),  // Find this in your bin/cache directory.
  };
  FlutterEngine engine = nullptr;
  FlutterEngineResult result =
      FlutterEngineRun(FLUTTER_ENGINE_VERSION, &config,  // renderer
                       &args, window, &engine);
  if (result != kSuccess || engine == nullptr) {
    std::cout << "Could not run the Flutter Engine." << std::endl;
    return false;
  }
 
  glfwSetWindowUserPointer(window, engine);
  GLFWwindowSizeCallback(window, kInitialWindowWidth, kInitialWindowHeight);
 
  return true;
}

Variable Documentation

g_pixelRatio

double g_pixelRatio = 1.0

static

Definition at line 13 of file FlutterEmbedderGLFW.cc.

kImplicitViewId

constexpr FlutterViewId kImplicitViewId = 0

staticconstexpr

Definition at line 16 of file FlutterEmbedderGLFW.cc.

kInitialWindowHeight

const size_t kInitialWindowHeight = 600

static

Definition at line 15 of file FlutterEmbedderGLFW.cc.

kInitialWindowWidth

const size_t kInitialWindowWidth = 800

static

Definition at line 14 of file FlutterEmbedderGLFW.cc.