add example for glfw3 and opengl3

2025-08-11 04:18:29 +01:00 · 2022-11-15 19:27:21 -05:00
parent ce3b504e11
commit a9a9fa4e9e
2 changed files with 259 additions and 0 deletions
--- a/backend_test/example_glfw_opengl3/main.c
+++ b/backend_test/example_glfw_opengl3/main.c
@@ -0,0 +1,169 @@
+#define CIMGUI_DEFINE_ENUMS_AND_STRUCTS
+#include "cimgui.h"
+#include "cimgui_impl.h"
+#include <GLFW/glfw3.h>
+#include <stdio.h>
+#ifdef _MSC_VER
+#include <windows.h>
+#endif
+#include <GL/gl.h>
+#include <GL/glu.h>
+
+#ifdef IMGUI_HAS_IMSTR
+#define igBegin igBegin_Str
+#define igSliderFloat igSliderFloat_Str
+#define igCheckbox igCheckbox_Str
+#define igColorEdit3 igColorEdit3_Str
+#define igButton igButton_Str
+#endif
+
+GLFWwindow *window;
+
+int main(int argc, char *argv[])
+{
+
+  if (!glfwInit())
+    return -1;
+
+  // Decide GL+GLSL versions
+  glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
+  glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+
+#if __APPLE__
+  // GL 3.2 Core + GLSL 150
+  const char *glsl_version = "#version 150";
+#else
+  // GL 3.2 + GLSL 130
+  const char *glsl_version = "#version 130";
+#endif
+
+  // just an extra window hint for resize
+  glfwWindowHint(GLFW_RESIZABLE, GLFW_TRUE);
+
+  window = glfwCreateWindow(1024, 768, "Hello World!", NULL, NULL);
+  if (!window) 
+  {
+    printf("Failed to create window! Terminating!\n");
+    glfwTerminate();
+    return -1;
+  }
+
+  glfwMakeContextCurrent(window);
+
+  // enable vsync
+  glfwSwapInterval(1);
+
+  // check opengl version sdl uses
+  printf("opengl version: %s\n", (char *)glGetString(GL_VERSION));
+
+  // setup imgui
+  igCreateContext(NULL);
+
+  // set docking
+  ImGuiIO *ioptr = igGetIO();
+  ioptr->ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;   // Enable Keyboard Controls
+  //ioptr->ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;  // Enable Gamepad Controls
+#ifdef IMGUI_HAS_DOCK
+  ioptr->ConfigFlags |= ImGuiConfigFlags_DockingEnable;       // Enable Docking
+  ioptr->ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;     // Enable Multi-Viewport / Platform Windows
+#endif
+
+  ImGui_ImplGlfw_InitForOpenGL(window, true);
+  ImGui_ImplOpenGL3_Init(glsl_version);
+
+  igStyleColorsDark(NULL);
+  // ImFontAtlas_AddFontDefault(io.Fonts, NULL);
+
+  bool showDemoWindow = true;
+  bool showAnotherWindow = false;
+  ImVec4 clearColor;
+  clearColor.x = 0.45f;
+  clearColor.y = 0.55f;
+  clearColor.z = 0.60f;
+  clearColor.w = 1.00f;
+
+  // main event loop
+  bool quit = false;
+  while (!glfwWindowShouldClose(window))
+  {
+
+    glfwPollEvents();
+
+    // start imgui frame
+    ImGui_ImplOpenGL3_NewFrame();
+    ImGui_ImplGlfw_NewFrame();
+    igNewFrame();
+
+    if (showDemoWindow)
+      igShowDemoWindow(&showDemoWindow);
+
+    // show a simple window that we created ourselves.
+    {
+      static float f = 0.0f;
+      static int counter = 0;
+
+      igBegin("Hello, world!", NULL, 0);
+      igText("This is some useful text");
+      igCheckbox("Demo window", &showDemoWindow);
+      igCheckbox("Another window", &showAnotherWindow);
+
+      igSliderFloat("Float", &f, 0.0f, 1.0f, "%.3f", 0);
+      igColorEdit3("clear color", (float *)&clearColor, 0);
+
+      ImVec2 buttonSize;
+      buttonSize.x = 0;
+      buttonSize.y = 0;
+      if (igButton("Button", buttonSize))
+        counter++;
+      igSameLine(0.0f, -1.0f);
+      igText("counter = %d", counter);
+
+      igText("Application average %.3f ms/frame (%.1f FPS)",
+             1000.0f / igGetIO()->Framerate, igGetIO()->Framerate);
+      igEnd();
+    }
+
+    if (showAnotherWindow) 
+    {
+      igBegin("imgui Another Window", &showAnotherWindow, 0);
+      igText("Hello from imgui");
+      ImVec2 buttonSize;
+      buttonSize.x = 0;
+      buttonSize.y = 0;
+      if (igButton("Close me", buttonSize)) {
+        showAnotherWindow = false;
+      }
+      igEnd();
+    }
+
+    // render
+    igRender();
+    glfwMakeContextCurrent(window);
+    glViewport(0, 0, (int)ioptr->DisplaySize.x, (int)ioptr->DisplaySize.y);
+    glClearColor(clearColor.x, clearColor.y, clearColor.z, clearColor.w);
+    glClear(GL_COLOR_BUFFER_BIT);
+    ImGui_ImplOpenGL3_RenderDrawData(igGetDrawData());
+#ifdef IMGUI_HAS_DOCK
+    if (ioptr->ConfigFlags & ImGuiConfigFlags_ViewportsEnable) 
+    {
+      GLFWwindow *backup_current_window = glfwGetCurrentContext();
+      igUpdatePlatformWindows();
+      igRenderPlatformWindowsDefault(NULL, NULL);
+      glfwMakeContextCurrent(backup_current_window);
+    }
+#endif
+    glfwSwapBuffers(window);
+  }
+
+  // clean up
+  ImGui_ImplOpenGL3_Shutdown();
+  ImGui_ImplGlfw_Shutdown();
+  igDestroyContext(NULL);
+
+  glfwDestroyWindow(window);
+  glfwTerminate();
+
+  return 0;
+}