ref: 9c056f688221580abd90775544f4d963e7f9dc78
parent: cebd07a93936b7c64945802d216c57287bdced2c
author: Clownacy <Clownacy@users.noreply.github.com>
date: Wed Jul 8 12:18:38 EDT 2020
Add option to make DoConfig clone use OpenGL 2.1 This way, I can use it in my Windows 7 VM, where OpenGL 3.2 isn't available.
--- a/DoConfig/CMakeLists.txt
+++ b/DoConfig/CMakeLists.txt
@@ -1,5 +1,7 @@
cmake_minimum_required(VERSION 3.8)
+option(DOCONFIG_LEGACY_OPENGL "Use OpenGL 2.1 instead of 3.2" OFF)
+
option(PKG_CONFIG_STATIC_LIBS "On platforms with pkg-config, static-link the dependencies (good for Windows builds, so you don't need to bundle DLL files)" OFF)
option(MSVC_LINK_STATIC_RUNTIME "Link the static MSVC runtime library (Visual Studio only)" OFF)
@@ -17,8 +19,6 @@
"imgui/imgui_draw.cpp"
"imgui/imgui_impl_glfw.cpp"
"imgui/imgui_impl_glfw.h"
- "imgui/imgui_impl_opengl3.cpp"
- "imgui/imgui_impl_opengl3.h"
"imgui/imgui_internal.h"
"imgui/imgui_widgets.cpp"
"imgui/imstb_rectpack.h"
@@ -39,6 +39,19 @@
target_include_directories(DoConfig PRIVATE "../external/glad/include")
target_compile_definitions(DoConfig PRIVATE IMGUI_IMPL_OPENGL_LOADER_GLAD)
+
+if(DOCONFIG_LEGACY_OPENGL)
+ target_compile_definitions(DoConfig PRIVATE LEGACY_OPENGL)
+ target_sources(DoConfig PRIVATE
+ "imgui/imgui_impl_opengl2.cpp"
+ "imgui/imgui_impl_opengl2.h"
+ )
+else()
+ target_sources(DoConfig PRIVATE
+ "imgui/imgui_impl_opengl3.cpp"
+ "imgui/imgui_impl_opengl3.h"
+ )
+endif()
if(PKG_CONFIG_STATIC_LIBS)
target_link_options(DoConfig PRIVATE "-static")
--- a/DoConfig/DoConfig.cpp
+++ b/DoConfig/DoConfig.cpp
@@ -7,7 +7,11 @@
#include "imgui/imgui.h"
#include "imgui/imgui_impl_glfw.h"
+#ifdef LEGACY_OPENGL
+#include "imgui/imgui_impl_opengl2.h"
+#else
#include "imgui/imgui_impl_opengl3.h"
+#endif
#define WINDOW_WIDTH 360
#define WINDOW_HEIGHT 290
@@ -49,11 +53,16 @@
if (glfwInit())
{+ #ifdef LEGACY_OPENGL
+ glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 2);
+ glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 1);
+ #else
const char *glsl_version = "#version 150 core";
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);
+ #endif
glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
@@ -66,8 +75,12 @@
if (gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
{- // Check if the platform supports OpenGL 3.2
+ // Check if the platform supports the version of OpenGL we want
+ #ifdef LEGACY_OPENGL
+ if (GLAD_GL_VERSION_2_1)
+ #else
if (GLAD_GL_VERSION_3_2)
+ #endif
{///////////////////////////
// Initialise Dear ImGui //
@@ -79,7 +92,11 @@
io.IniFilename = NULL; // Disable `imgui.ini`
ImGui_ImplGlfw_InitForOpenGL(window, true);
+ #ifdef LEGACY_OPENGL
+ ImGui_ImplOpenGL2_Init();
+ #else
ImGui_ImplOpenGL3_Init(glsl_version);
+ #endif
/////////////////////
// Load Config.dat //
@@ -137,7 +154,11 @@
{glfwPollEvents();
+ #ifdef LEGACY_OPENGL
+ ImGui_ImplOpenGL2_NewFrame();
+ #else
ImGui_ImplOpenGL3_NewFrame();
+ #endif
ImGui_ImplGlfw_NewFrame();
ImGui::NewFrame();
@@ -271,7 +292,11 @@
ImGui::Render();
glClear(GL_COLOR_BUFFER_BIT);
+ #ifdef LEGACY_OPENGL
+ ImGui_ImplOpenGL2_RenderDrawData(ImGui::GetDrawData());
+ #else
ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+ #endif
glfwSwapBuffers(window);
}
}
@@ -278,7 +303,11 @@
}
}
+ #ifdef LEGACY_OPENGL
+ ImGui_ImplOpenGL2_Shutdown();
+ #else
ImGui_ImplOpenGL3_Shutdown();
+ #endif
ImGui_ImplGlfw_Shutdown();
ImGui::DestroyContext();
--- /dev/null
+++ b/DoConfig/imgui/imgui_impl_opengl2.cpp
@@ -1,0 +1,248 @@
+// dear imgui: Renderer for OpenGL2 (legacy OpenGL, fixed pipeline)
+// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+
+// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
+// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
+// https://github.com/ocornut/imgui
+
+// **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
+// **Prefer using the code in imgui_impl_opengl3.cpp**
+// This code is mostly provided as a reference to learn how ImGui integration works, because it is shorter to read.
+// If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything more
+// complicated, will require your code to reset every single OpenGL attributes to their initial state, and might
+// confuse your GPU driver.
+// The GL2 code is unable to reset attributes or even call e.g. "glUseProgram(0)" because they don't exist in that API.
+
+// CHANGELOG
+// (minor and older changes stripped away, please see git history for details)
+// 2020-01-23: OpenGL: Explicitly backup, setup and restore GL_TEXTURE_ENV to increase compatibility with legacy OpenGL applications.
+// 2019-04-30: OpenGL: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
+// 2019-02-11: OpenGL: Projecting clipping rectangles correctly using draw_data->FramebufferScale to allow multi-viewports for retina display.
+// 2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
+// 2018-08-03: OpenGL: Disabling/restoring GL_LIGHTING and GL_COLOR_MATERIAL to increase compatibility with legacy OpenGL applications.
+// 2018-06-08: Misc: Extracted imgui_impl_opengl2.cpp/.h away from the old combined GLFW/SDL+OpenGL2 examples.
+// 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
+// 2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback and exposed ImGui_ImplOpenGL2_RenderDrawData() in the .h file so you can call it yourself.
+// 2017-09-01: OpenGL: Save and restore current polygon mode.
+// 2016-09-10: OpenGL: Uploading font texture as RGBA32 to increase compatibility with users shaders (not ideal).
+// 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
+
+#include "imgui.h"
+#include "imgui_impl_opengl2.h"
+#if defined(_MSC_VER) && _MSC_VER <= 1500 // MSVC 2008 or earlier
+#include <stddef.h> // intptr_t
+#else
+#include <stdint.h> // intptr_t
+#endif
+
+// Include OpenGL header (without an OpenGL loader) requires a bit of fiddling
+#if defined(_WIN32) && !defined(APIENTRY)
+#define APIENTRY __stdcall // It is customary to use APIENTRY for OpenGL function pointer declarations on all platforms. Additionally, the Windows OpenGL header needs APIENTRY.
+#endif
+#if defined(_WIN32) && !defined(WINGDIAPI)
+#define WINGDIAPI __declspec(dllimport) // Some Windows OpenGL headers need this
+#endif
+#if defined(__APPLE__)
+#define GL_SILENCE_DEPRECATION
+#include <OpenGL/gl.h>
+#else
+#include <GL/gl.h>
+#endif
+
+// OpenGL Data
+static GLuint g_FontTexture = 0;
+
+// Functions
+bool ImGui_ImplOpenGL2_Init()
+{+ // Setup back-end capabilities flags
+ ImGuiIO& io = ImGui::GetIO();
+ io.BackendRendererName = "imgui_impl_opengl2";
+ return true;
+}
+
+void ImGui_ImplOpenGL2_Shutdown()
+{+ ImGui_ImplOpenGL2_DestroyDeviceObjects();
+}
+
+void ImGui_ImplOpenGL2_NewFrame()
+{+ if (!g_FontTexture)
+ ImGui_ImplOpenGL2_CreateDeviceObjects();
+}
+
+static void ImGui_ImplOpenGL2_SetupRenderState(ImDrawData* draw_data, int fb_width, int fb_height)
+{+ // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill.
+ glEnable(GL_BLEND);
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ glDisable(GL_CULL_FACE);
+ glDisable(GL_DEPTH_TEST);
+ glDisable(GL_LIGHTING);
+ glDisable(GL_COLOR_MATERIAL);
+ glEnable(GL_SCISSOR_TEST);
+ glEnableClientState(GL_VERTEX_ARRAY);
+ glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+ glEnableClientState(GL_COLOR_ARRAY);
+ glEnable(GL_TEXTURE_2D);
+ glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+
+ // If you are using this code with non-legacy OpenGL header/contexts (which you should not, prefer using imgui_impl_opengl3.cpp!!),
+ // you may need to backup/reset/restore current shader using the lines below. DO NOT MODIFY THIS FILE! Add the code in your calling function:
+ // GLint last_program;
+ // glGetIntegerv(GL_CURRENT_PROGRAM, &last_program);
+ // glUseProgram(0);
+ // ImGui_ImplOpenGL2_RenderDrawData(...);
+ // glUseProgram(last_program)
+
+ // Setup viewport, orthographic projection matrix
+ // Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
+ glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
+ glMatrixMode(GL_PROJECTION);
+ glPushMatrix();
+ glLoadIdentity();
+ glOrtho(draw_data->DisplayPos.x, draw_data->DisplayPos.x + draw_data->DisplaySize.x, draw_data->DisplayPos.y + draw_data->DisplaySize.y, draw_data->DisplayPos.y, -1.0f, +1.0f);
+ glMatrixMode(GL_MODELVIEW);
+ glPushMatrix();
+ glLoadIdentity();
+}
+
+// OpenGL2 Render function.
+// (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
+// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
+void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data)
+{+ // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
+ int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
+ int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
+ if (fb_width == 0 || fb_height == 0)
+ return;
+
+ // Backup GL state
+ GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+ GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
+ GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
+ GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
+ GLint last_tex_env_mode; glGetTexEnviv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, &last_tex_env_mode);
+ glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT);
+
+ // Setup desired GL state
+ ImGui_ImplOpenGL2_SetupRenderState(draw_data, fb_width, fb_height);
+
+ // Will project scissor/clipping rectangles into framebuffer space
+ ImVec2 clip_off = draw_data->DisplayPos; // (0,0) unless using multi-viewports
+ ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)
+
+ // Render command lists
+ for (int n = 0; n < draw_data->CmdListsCount; n++)
+ {+ const ImDrawList* cmd_list = draw_data->CmdLists[n];
+ const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
+ const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
+ glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, pos)));
+ glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, uv)));
+ glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + IM_OFFSETOF(ImDrawVert, col)));
+
+ for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++)
+ {+ const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
+ if (pcmd->UserCallback)
+ {+ // User callback, registered via ImDrawList::AddCallback()
+ // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
+ if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
+ ImGui_ImplOpenGL2_SetupRenderState(draw_data, fb_width, fb_height);
+ else
+ pcmd->UserCallback(cmd_list, pcmd);
+ }
+ else
+ {+ // Project scissor/clipping rectangles into framebuffer space
+ ImVec4 clip_rect;
+ clip_rect.x = (pcmd->ClipRect.x - clip_off.x) * clip_scale.x;
+ clip_rect.y = (pcmd->ClipRect.y - clip_off.y) * clip_scale.y;
+ clip_rect.z = (pcmd->ClipRect.z - clip_off.x) * clip_scale.x;
+ clip_rect.w = (pcmd->ClipRect.w - clip_off.y) * clip_scale.y;
+
+ if (clip_rect.x < fb_width && clip_rect.y < fb_height && clip_rect.z >= 0.0f && clip_rect.w >= 0.0f)
+ {+ // Apply scissor/clipping rectangle
+ glScissor((int)clip_rect.x, (int)(fb_height - clip_rect.w), (int)(clip_rect.z - clip_rect.x), (int)(clip_rect.w - clip_rect.y));
+
+ // Bind texture, Draw
+ glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
+ glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer);
+ }
+ }
+ idx_buffer += pcmd->ElemCount;
+ }
+ }
+
+ // Restore modified GL state
+ glDisableClientState(GL_COLOR_ARRAY);
+ glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+ glDisableClientState(GL_VERTEX_ARRAY);
+ glBindTexture(GL_TEXTURE_2D, (GLuint)last_texture);
+ glMatrixMode(GL_MODELVIEW);
+ glPopMatrix();
+ glMatrixMode(GL_PROJECTION);
+ glPopMatrix();
+ glPopAttrib();
+ glPolygonMode(GL_FRONT, (GLenum)last_polygon_mode[0]); glPolygonMode(GL_BACK, (GLenum)last_polygon_mode[1]);
+ glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]);
+ glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, last_tex_env_mode);
+}
+
+bool ImGui_ImplOpenGL2_CreateFontsTexture()
+{+ // Build texture atlas
+ ImGuiIO& io = ImGui::GetIO();
+ unsigned char* pixels;
+ int width, height;
+ io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
+
+ // Upload texture to graphics system
+ GLint last_texture;
+ glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
+ glGenTextures(1, &g_FontTexture);
+ glBindTexture(GL_TEXTURE_2D, g_FontTexture);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+ glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+
+ // Store our identifier
+ io.Fonts->TexID = (ImTextureID)(intptr_t)g_FontTexture;
+
+ // Restore state
+ glBindTexture(GL_TEXTURE_2D, last_texture);
+
+ return true;
+}
+
+void ImGui_ImplOpenGL2_DestroyFontsTexture()
+{+ if (g_FontTexture)
+ {+ ImGuiIO& io = ImGui::GetIO();
+ glDeleteTextures(1, &g_FontTexture);
+ io.Fonts->TexID = 0;
+ g_FontTexture = 0;
+ }
+}
+
+bool ImGui_ImplOpenGL2_CreateDeviceObjects()
+{+ return ImGui_ImplOpenGL2_CreateFontsTexture();
+}
+
+void ImGui_ImplOpenGL2_DestroyDeviceObjects()
+{+ ImGui_ImplOpenGL2_DestroyFontsTexture();
+}
--- /dev/null
+++ b/DoConfig/imgui/imgui_impl_opengl2.h
@@ -1,0 +1,31 @@
+// dear imgui: Renderer for OpenGL2 (legacy OpenGL, fixed pipeline)
+// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
+
+// Implemented features:
+// [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+
+// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
+// If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
+// https://github.com/ocornut/imgui
+
+// **DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL (SHADERS, VBO, VAO, etc.)**
+// **Prefer using the code in imgui_impl_opengl3.cpp**
+// This code is mostly provided as a reference to learn how ImGui integration works, because it is shorter to read.
+// If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything more
+// complicated, will require your code to reset every single OpenGL attributes to their initial state, and might
+// confuse your GPU driver.
+// The GL2 code is unable to reset attributes or even call e.g. "glUseProgram(0)" because they don't exist in that API.
+
+#pragma once
+#include "imgui.h" // IMGUI_IMPL_API
+
+IMGUI_IMPL_API bool ImGui_ImplOpenGL2_Init();
+IMGUI_IMPL_API void ImGui_ImplOpenGL2_Shutdown();
+IMGUI_IMPL_API void ImGui_ImplOpenGL2_NewFrame();
+IMGUI_IMPL_API void ImGui_ImplOpenGL2_RenderDrawData(ImDrawData* draw_data);
+
+// Called by Init/NewFrame/Shutdown
+IMGUI_IMPL_API bool ImGui_ImplOpenGL2_CreateFontsTexture();
+IMGUI_IMPL_API void ImGui_ImplOpenGL2_DestroyFontsTexture();
+IMGUI_IMPL_API bool ImGui_ImplOpenGL2_CreateDeviceObjects();
+IMGUI_IMPL_API void ImGui_ImplOpenGL2_DestroyDeviceObjects();
--- a/README.md
+++ b/README.md
@@ -75,6 +75,7 @@
`-DFIX_BUGS=ON` | Fix various bugs in the game
`-DDEBUG_SAVE=ON` | Re-enable the ability to drag-and-drop save files onto the window
`-DDOCONFIG=OFF` | Disable compiling the DoConfig tool (it is not useful for console ports)
+`-DDOCONFIG_LEGACY_OPENGL=ON` | Make DoConfig use OpenGL 2.1 instead of OpenGL 3.2 (useful for older/limited platforms)
`-DBACKEND_RENDERER=OpenGL3` | Render with OpenGL 3.2 (hardware-accelerated)
`-DBACKEND_RENDERER=OpenGLES2` | Render with OpenGL ES 2.0 (hardware-accelerated)
`-DBACKEND_RENDERER=SDLTexture` | (Default) Render with SDL2's Texture API (hardware-accelerated) (note: requires `-DBACKEND_PLATFORM=SDL2`)