[wpigui,dlt,glass,ov] Support arm in GUI tools (#4527)

wpigui/src/main/native/opengl2/wpigui_opengl2.cpp

@@ -0,0 +1,131 @@
+// Copyright (c) FIRST and other WPILib contributors.
+// Open Source Software; you can modify and/or share it under the terms of
+// the WPILib BSD license file in the root directory of this project.
+
+#include <cstdio>
+
+#include <GLFW/glfw3.h>
+#include <imgui.h>
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl2.h>
+
+#include "wpigui.h"
+#include "wpigui_internal.h"
+
+using namespace wpi::gui;
+
+static bool gPlatformValid = false;
+
+namespace wpi {
+
+void gui::PlatformCreateContext() {}
+
+void gui::PlatformDestroyContext() {}
+
+void gui::PlatformGlfwInitHints() {}
+
+void gui::PlatformGlfwWindowHints() {
+  // GL 2.1
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+  glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
+
+  // enable 4xMSAA
+  glfwWindowHint(GLFW_SAMPLES, 4);
+}
+
+bool gui::PlatformInitRenderer() {
+  glfwMakeContextCurrent(gContext->window);
+
+  glfwSwapInterval(1);  // Enable vsync
+
+  // Turn on multisampling
+  glEnable(GL_MULTISAMPLE);
+
+  // Setup Platform/Renderer bindings
+  ImGui_ImplGlfw_InitForOpenGL(gContext->window, true);
+
+  ImGui_ImplOpenGL2_Init();
+
+  gPlatformValid = true;
+  return true;
+}
+
+void gui::PlatformRenderFrame() {
+  ImGui_ImplOpenGL2_NewFrame();
+
+  CommonRenderFrame();
+
+  int display_w, display_h;
+  glfwGetFramebufferSize(gContext->window, &display_w, &display_h);
+  glViewport(0, 0, display_w, display_h);
+  glClearColor(gContext->clearColor.x, gContext->clearColor.y,
+               gContext->clearColor.z, gContext->clearColor.w);
+  glClear(GL_COLOR_BUFFER_BIT);
+  ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+
+  glfwSwapBuffers(gContext->window);
+}
+
+void gui::PlatformShutdown() {
+  gPlatformValid = false;
+  ImGui_ImplOpenGL2_Shutdown();
+}
+
+void gui::PlatformFramebufferSizeChanged(int width, int height) {}
+
+static inline GLenum GLPixelFormat(PixelFormat format) {
+  switch (format) {
+    case kPixelRGBA:
+      return GL_RGBA;
+    case kPixelBGRA:
+      return GL_BGRA;
+    default:
+      return GL_RGBA;
+  }
+}
+
+ImTextureID gui::CreateTexture(PixelFormat format, int width, int height,
+                               const unsigned char* data) {
+  if (!gPlatformValid) {
+    return nullptr;
+  }
+
+  // Create a OpenGL texture identifier
+  GLuint texture;
+  glGenTextures(1, &texture);
+  glBindTexture(GL_TEXTURE_2D, texture);
+
+  // Setup filtering parameters for display
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+  // Upload pixels into texture
+  glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+  glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
+               GLPixelFormat(format), GL_UNSIGNED_BYTE, data);
+
+  return reinterpret_cast<ImTextureID>(static_cast<uintptr_t>(texture));
+}
+
+void gui::UpdateTexture(ImTextureID texture, PixelFormat format, int width,
+                        int height, const unsigned char* data) {
+  GLuint glTexture = static_cast<GLuint>(reinterpret_cast<uintptr_t>(texture));
+  if (glTexture == 0) {
+    return;
+  }
+  glBindTexture(GL_TEXTURE_2D, glTexture);
+  glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width, height, GLPixelFormat(format),
+                  GL_UNSIGNED_BYTE, data);
+}
+
+void gui::DeleteTexture(ImTextureID texture) {
+  if (!gPlatformValid) {
+    return;
+  }
+  GLuint glTexture = static_cast<GLuint>(reinterpret_cast<uintptr_t>(texture));
+  if (glTexture != 0) {
+    glDeleteTextures(1, &glTexture);
+  }
+}
+
+}  // namespace wpi