From 0e3d63e9b362a26b31329f1594568e572941b1a0 Mon Sep 17 00:00:00 2001 From: omar Date: Thu, 21 Jun 2018 09:30:09 +0200 Subject: [PATCH] Destroyed Getting Started (markdown) --- Getting-Started.md | 325 --------------------------------------------- 1 file changed, 325 deletions(-) delete mode 100644 Getting-Started.md diff --git a/Getting-Started.md b/Getting-Started.md deleted file mode 100644 index 71735bd..0000000 --- a/Getting-Started.md +++ /dev/null @@ -1,325 +0,0 @@ -** THIS PAGE WAS A PROPOSAL AND HAS NEVER BEEN UPDATED, PREFER REFERRING TO EXAMPLES/ ** - -\* **This page is a proposal that has been given up on** \* -\* Please refer to imgui.cpp and regular examples/ for up to date instructions \* - -This article will guide you through getting up and running using GLFW with as many assumptions about your system as possible. ImGui is completely hardware/library agnostic and runs on everything, you only need to feed it with inputs and render textured triangles as output. As such, GLFW is merely used a convenient example because it is simple to use and popular. - -![image](https://cloud.githubusercontent.com/assets/2152766/14699172/7591cd04-078d-11e6-83ca-7f95977dd4e8.png) - -**You will learn** - -- How this project is organised -- How to open a window using GLFW -- How to render an ImGui window into the GLFW window -- How to render text into the ImGui window - -**You are** - -- On Linux -- Using C++11 -- Using OpenGL 3.3 or above, core profile -- Using clang 3.4 or above -- Using glfw 3.0 or above - -
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- -### Organisation - -``` -| File | Description -|--------------------|-------------------- -| imgui/ | -| examples/ | Some examples for various backends and windowing libraries -| extra_fonts/ | Optional assets -| imconfig.h | Configuration file -| imgui.cpp | -| imgui.h | -| imgui_demo.cpp | Demonstration code, useful to keep around, run and learn about imgui -| imgui_draw.cpp | -| imgui_internal.h | Internal details, without guarantee of backward compatibility -| stb_* | External library -``` - -
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- -### Layout - -This is the layout of your code. - -``` -| Directory | Description -|---------------------|---------------------------------- -| myproject/ | -| build/ | Output goes here -| include/ | Any include files you may eventually have -| ext/ | External projects -| glfw/ | -| imgui/ | -| src/ | -| main.cpp | Your single source file -| build.sh | Your build script -``` - -```bash -$ cd myproject/ext -$ git clone https://github.com/ocornut/imgui.git -$ git clone https://github.com/glfw/glfw.git -``` -
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- -### Build - -Here is how your code will be built. - -```bash -$ cd myproject -$ ./build.sh -``` - -**build.sh** - -```bash -#!/usr/bin/env bash - -mkdir -p build && \ -pushd build && \ -clang++ \ - -o main \ - ../ext/imgui/imgui.cpp \ - ../ext/imgui/imgui_draw.cpp \ - ../src/main.cpp \ - -Wall \ - -g `# Generate complete debug info` \ - -std=c++11 \ - -I ../include \ - -I ../ext/glfw/include \ - -I ../ext/imgui \ - -L ../lib \ - -lglfw3 \ - -lGL \ - -lGLU \ - -lX11 \ - -lXxf86vm \ - -lXrandr \ - -lpthread \ - -lXi \ - -lXinerama \ - -lXcursor && \ -popd || exit 1 -``` - -
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- -### Source - -Here is the source. - -**main.cpp** - -```cpp -// dear imgui minimal example. - -#include -#include "GLFW/glfw3.h" -#include "imgui.h" - -void setup(GLFWwindow* window); -void renderer(ImDrawData* draw_data); - -int main(void) -{ - if (!glfwInit()) - { - exit(EXIT_FAILURE); - } - - static GLFWwindow* window { - glfwCreateWindow(320, 240, "Simple example", NULL, NULL) - }; - - if (!window) - { - glfwTerminate(); - exit(EXIT_FAILURE); - } - - glfwMakeContextCurrent(window); - - // Close window on pressing ESC - glfwSetKeyCallback(window, [](GLFWwindow* window, int key, int scancode, int action, int mods) { - if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS) - glfwSetWindowShouldClose(window, GL_TRUE); - }); - - setup(window); - - glClearColor(0.1f, 0.1f, 0.1f, 1.0f); - while (!glfwWindowShouldClose(window)) - { - glClear(GL_COLOR_BUFFER_BIT); - - glfwPollEvents(); - - // Use ImGui functions between here and Render() - ImGui::NewFrame(); - - // This creates a window - ImGui::Begin("Window Title Here"); - ImGui::Text("Hello, world!"); - ImGui::End(); - - // ImGui functions end here - ImGui::Render(); - - glfwSwapBuffers(window); - } - - glfwDestroyWindow(window); - glfwTerminate(); - - exit(EXIT_SUCCESS); -} - -/*! /brief Initialise the ImGuiIO struct. - * - * The ImGuiIO struct is the main configuration and - * I/O between your application and ImGui. - */ -void setup(GLFWwindow* window) -{ - unsigned char* pixels; - int width, - height, - display_width, - display_height; - GLuint g_FontTexture; - ImGui::CreateContext(); - ImGuiIO& io { ImGui::GetIO() }; - - io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height); - - // 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); - glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, pixels); - - // Get display size - glfwGetWindowSize(window, &width, &height); - glfwGetFramebufferSize(window, &display_width, &display_height); - - io.DisplaySize = ImVec2((float)width, (float)height); - io.RenderDrawListsFn = renderer; - io.Fonts->TexID = (void *)(intptr_t)g_FontTexture; - - // Restore state - glBindTexture(GL_TEXTURE_2D, last_texture); -} - -/*! /brief Boilerplate function for OpenGL 2.0 rendering. - * - * This function isn't written by us, but is mandatory - * boilerplate from the library. It can be copy/pasted - * into your projects, but should really be part of the - * library itself? - */ -void renderer(ImDrawData* draw_data) -{ - ImGuiIO& io { ImGui::GetIO() }; - int fb_width { (int)(io.DisplaySize.x * io.DisplayFramebufferScale.x) }; - int fb_height { (int)(io.DisplaySize.y * io.DisplayFramebufferScale.y) }; - - draw_data->ScaleClipRects(io.DisplayFramebufferScale); - - GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); - GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport); - glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT); - glEnable(GL_BLEND); - glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); - glDisable(GL_CULL_FACE); - glDisable(GL_DEPTH_TEST); - glEnable(GL_SCISSOR_TEST); - glEnableClientState(GL_VERTEX_ARRAY); - glEnableClientState(GL_TEXTURE_COORD_ARRAY); - glEnableClientState(GL_COLOR_ARRAY); - glEnable(GL_TEXTURE_2D); - - // Setup viewport, orthographic projection matrix - glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height); - glMatrixMode(GL_PROJECTION); - glPushMatrix(); - glLoadIdentity(); - glOrtho(0.0f, io.DisplaySize.x, io.DisplaySize.y, 0.0f, -1.0f, +1.0f); - glMatrixMode(GL_MODELVIEW); - glPushMatrix(); - glLoadIdentity(); - - // Render command lists - #define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT)) - for (int n = 0; n < draw_data->CmdListsCount; n++) - { - const ImDrawList* cmd_list = draw_data->CmdLists[n]; - const unsigned char* vtx_buffer = (const unsigned char*)&cmd_list->VtxBuffer.front(); - const ImDrawIdx* idx_buffer = &cmd_list->IdxBuffer.front(); - glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, pos))); - glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, uv))); - glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (void*)(vtx_buffer + 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) - { - pcmd->UserCallback(cmd_list, pcmd); - } - else - { - glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); - glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y)); - glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer); - } - idx_buffer += pcmd->ElemCount; - } - } - #undef OFFSETOF - - // Restore modified state - glDisableClientState(GL_COLOR_ARRAY); - glDisableClientState(GL_TEXTURE_COORD_ARRAY); - glDisableClientState(GL_VERTEX_ARRAY); - glBindTexture(GL_TEXTURE_2D, last_texture); - glMatrixMode(GL_MODELVIEW); - glPopMatrix(); - glMatrixMode(GL_PROJECTION); - glPopMatrix(); - glPopAttrib(); - glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]); -} -``` - -
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- -#### TODO - -Here are some ideas for how to improve and shorten this article. - -- Add screenshot of result -- Reduce requirements, such as C++11 -- Increase compatibility, such as including a cl.exe build script. -- Remove lines that aren't absolutely critical -- Remove `renderer()` - Seems unnecessary and better included with ImGui? -- Remove need to manually upload texture to GPU in `setup()`, can/should be included in ImGui? \ No newline at end of file