Nav: working on early bits of documentation (#323)

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ocornut 2016-07-31 15:41:51 +02:00
parent a154625a56
commit 1ecbf73c97

174
imgui.cpp
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Designed for developers and content-creators, not the typical end-user! Some of the weaknesses includes:
- doesn't look fancy, doesn't animate
- limited layout features, intricate layouts are typically crafted in code
- occasionally uses statically sized buffers for string manipulations - won't crash, but some very long pieces of text may be clipped. functions like ImGui::TextUnformatted() don't have such restriction.
END-USER GUIDE
==============
- double-click title bar to collapse window
- click upper right corner to close a window, available when 'bool* p_open' is passed to ImGui::Begin()
- click and drag on lower right corner to resize window
- click and drag on any empty space to move window
- double-click/double-tap on lower right corner grip to auto-fit to content
- Double-click title bar to collapse window
- Click upper right corner to close a window, available when 'bool* p_open' is passed to ImGui::Begin()
- Click and drag on lower right corner to resize window
- Click and drag on any empty space to move window
- Double-click/double-tap on lower right corner grip to auto-fit to content
- TAB/SHIFT+TAB to cycle through keyboard editable fields
- use mouse wheel to scroll
- use CTRL+mouse wheel to zoom window contents (if IO.FontAllowScaling is true)
- Use mouse wheel to scroll
- Use CTRL+mouse wheel to zoom window contents (if io.FontAllowScaling is true)
- CTRL+Click on a slider or drag box to input value as text
- text editor:
- Text editor:
- Hold SHIFT or use mouse to select text.
- CTRL+Left/Right to word jump
- CTRL+Shift+Left/Right to select words
@ -75,75 +74,109 @@
- CTRL+Z,CTRL+Y to undo/redo
- ESCAPE to revert text to its original value
- You can apply arithmetic operators +,*,/ on numerical values. Use +- to subtract (because - would set a negative value!)
- Controls are automatically adjusted for OSX to match standard OSX text editing operations.
- Gamepad/keyboard navigation are in beta-phase, see Programmer Guide below.
PROGRAMMER GUIDE
================
- read the FAQ below this section!
- your code creates the UI, if your code doesn't run the UI is gone! == very dynamic UI, no construction/destructions steps, less data retention on your side, no state duplication, less sync, less bugs.
- call and read ImGui::ShowTestWindow() for demo code demonstrating most features.
- see examples/ folder for standalone sample applications. Prefer reading examples/opengl_example/ first as it is the simplest.
you may be able to grab and copy a ready made imgui_impl_*** file from the examples/.
- customization: PushStyleColor()/PushStyleVar() or the style editor to tweak the look of the interface (e.g. if you want a more compact UI or a different color scheme).
READ FIRST
- getting started:
- init: call ImGui::GetIO() to retrieve the ImGuiIO structure and fill the fields marked 'Settings'.
- init: call io.Fonts->GetTexDataAsRGBA32(...) and load the font texture pixels into graphics memory.
- every frame:
1/ in your mainloop or right after you got your keyboard/mouse info, call ImGui::GetIO() and fill the fields marked 'Input'
2/ call ImGui::NewFrame() as early as you can!
3/ use any ImGui function you want between NewFrame() and Render()
4/ call ImGui::Render() as late as you can to end the frame and finalize render data. it will call your RenderDrawListFn handler that you set in the IO structure.
(if you don't need to render, you still need to call Render() and ignore the callback, or call EndFrame() instead. if you call neither some aspects of windows focusing/moving will appear broken.)
- all rendering information are stored into command-lists until ImGui::Render() is called.
- ImGui never touches or know about your GPU state. the only function that knows about GPU is the RenderDrawListFn handler that you provide.
- effectively it means you can create widgets at any time in your code, regardless of considerations of being in "update" vs "render" phases of your own application.
- refer to the examples applications in the examples/ folder for instruction on how to setup your code.
- a typical application skeleton may be:
- Read the FAQ below this section!
- Your code creates the UI, if your code doesn't run the UI is gone! == very dynamic UI, no construction/destructions steps, less data retention on your side, no state duplication, less sync, less bugs.
- Call and read ImGui::ShowTestWindow() for demo code demonstrating most features.
- Customization: PushStyleColor()/PushStyleVar() or the style editor to tweak the look of the interface (e.g. if you want a more compact UI or a different color scheme).
// Application init
ImGuiIO& io = ImGui::GetIO();
io.DisplaySize.x = 1920.0f;
io.DisplaySize.y = 1280.0f;
io.IniFilename = "imgui.ini";
io.RenderDrawListsFn = my_render_function; // Setup a render function, or set to NULL and call GetDrawData() after Render() to access the render data.
// TODO: Fill others settings of the io structure
GETTING STARTED WITH INTEGRATING IN YOUR ENGINE
// Load texture atlas
// There is a default font so you don't need to care about choosing a font yet
unsigned char* pixels;
int width, height;
io.Fonts->GetTexDataAsRGBA32(pixels, &width, &height);
// TODO: At this points you've got a texture pointed to by 'pixels' and you need to upload that your your graphic system
// TODO: Store your texture pointer/identifier (whatever your engine uses) in 'io.Fonts->TexID'
- See examples/ folder for standalone sample applications. Prefer reading examples/opengl_example/ first as it is the simplest.
You may be able to grab and copy a ready made imgui_impl_*** file from the examples/.
- Init: call ImGui::GetIO() to retrieve the ImGuiIO structure and fill the fields marked 'Settings'.
- Init: call io.Fonts->GetTexDataAsRGBA32(...) and load the font texture pixels into graphics memory.
- Every frame:
1/ in your mainloop or right after you got your keyboard/mouse info, call ImGui::GetIO() and fill the fields marked 'Input'
2/ call ImGui::NewFrame() as early as you can!
3/ use any ImGui function you want between NewFrame() and Render()
4/ call ImGui::Render() as late as you can to end the frame and finalize render data. it will call your RenderDrawListFn handler that you set in the IO structure.
(if you don't need to render, you still need to call Render() and ignore the callback, or call EndFrame() instead. if you call neither some aspects of windows focusing/moving will appear broken.)
- All rendering information are stored into command-lists until ImGui::Render() is called.
- ImGui never touches or know about your GPU state. the only function that knows about GPU is the RenderDrawListFn handler that you provide.
- Effectively it means you can create widgets at any time in your code, regardless of considerations of being in "update" vs "render" phases of your own application.
- Refer to the examples applications in the examples/ folder for instruction on how to setup your code.
- A typical application skeleton may be:
// Application main loop
while (true)
{
// 1) get low-level inputs (e.g. on Win32, GetKeyboardState(), or poll your events, etc.)
// TODO: fill all fields of IO structure and call NewFrame
ImGuiIO& io = ImGui::GetIO();
io.DeltaTime = 1.0f/60.0f;
io.MousePos = mouse_pos;
io.MouseDown[0] = mouse_button_0;
io.MouseDown[1] = mouse_button_1;
io.KeysDown[i] = ...
// Application init
ImGuiIO& io = ImGui::GetIO();
io.DisplaySize.x = 1920.0f;
io.DisplaySize.y = 1280.0f;
io.IniFilename = "imgui.ini";
io.RenderDrawListsFn = my_render_function; // Setup a render function, or set to NULL and call GetDrawData() after Render() to access the render data.
// TODO: Fill others settings of the io structure
// 2) call NewFrame(), after this point you can use ImGui::* functions anytime
ImGui::NewFrame();
// Load texture atlas (there is a default font so you don't need to care about choosing a font yet)
unsigned char* pixels;
int width, height;
io.Fonts->GetTexDataAsRGBA32(pixels, &width, &height);
// TODO: At this points you've got a texture pointed to by 'pixels' and you need to upload that your your graphic system
// TODO: Store your texture pointer/identifier (whatever your engine uses) in 'io.Fonts->TexID'
// 3) most of your application code here
MyGameUpdate(); // may use any ImGui functions, e.g. ImGui::Begin("My window"); ImGui::Text("Hello, world!"); ImGui::End();
MyGameRender(); // may use any ImGui functions
// Application main loop
while (true)
{
// 1) get low-level inputs (e.g. on Win32, GetKeyboardState(), or poll your events, etc.)
// TODO: fill all fields of IO structure and call NewFrame
ImGuiIO& io = ImGui::GetIO();
io.DeltaTime = 1.0f/60.0f;
io.MousePos = mouse_pos;
io.MouseDown[0] = mouse_button_0;
io.MouseDown[1] = mouse_button_1;
io.KeysDown[i] = ...
// 4) render & swap video buffers
ImGui::Render();
SwapBuffers();
}
// 2) call NewFrame(), after this point you can use ImGui::* functions anytime
ImGui::NewFrame();
- You can read back 'io.WantCaptureMouse', 'io.WantCaptureKeybord' etc. flags from the IO structure to tell how ImGui intends to use your
inputs and to know if you should share them or hide them from the rest of your application. Read the FAQ below for more information.
// 3) most of your application code here
MyGameUpdate(); // may use any ImGui functions, e.g. ImGui::Begin("My window"); ImGui::Text("Hello, world!"); ImGui::End();
MyGameRender(); // may use any ImGui functions
// 4) render & swap video buffers
ImGui::Render();
SwapBuffers();
}
- You can read back 'io.WantCaptureMouse', 'io.WantCaptureKeybord' etc. flags from the IO structure to tell how ImGui intends to use your
inputs and to know if you should share them or hide them from the rest of your application. Read the FAQ below for more information.
USING GAMEPAD/KEYBOARD NAVIGATION [BETA]
- Gamepad/keyboard navigation support is available, it is currently in Beta and has issues. Your feedback and bug reports are welcome.
- See https://github.com/ocornut/imgui/issues/323 for discussion thread and ask questions.
- The current primary focus is to support game controllers.
- Consider emulating a mouse cursor with DualShock4 touch pad or a spare analog stick as a mouse-emulation fallback.
- Consider using Synergy host (on your computer) + uSynergy.c (in your console/tablet/phone app) to use PC mouse/keyboard.
- Being able to share and transition inputs between imgui navigation and your own game/application is tricky, and may requires further work on imgui.
For gamepad use, the easiest approach is to go all-or-nothing, with a buttons combo that toggle your inputs between imgui and your game/application.
For more advanced uses, you may want to use:
- io.NavUsable: true when a window is focused and it doesn't have the ImGuiWindowFlags_NoNavInputs flag set.
- io.NavActive: true when the navigation cursor is visible (and usually goes false when mouse is used).
- query focus information with IsWindowFocused(), IsAnyWindowFocused(), IsAnyItemFocused() functions.
The reality is more complex than what those flags can express. Please discuss your issues and usage scenario in the thread above.
As we head toward more keyboard-oriented development this aspect will need to be improved.
- It is recommended that you enable the 'io.NavMovesMouse' option. Enabling it instructs ImGui that it can request moving your move cursor to track navigated items and ease readability.
When enabled and using directional navigation (with d-pad or arrow keys), the NewFrame() functions may alter 'io.MousePos' and set 'io.WantMoveMouse' to notify you that it did so.
When that happens your back-end will need to move the OS mouse cursor on the _next_ frame. The examples binding in examples/ do that.
// Application init
io.NavMovesMouse = true;
// Application main loop
if (io.WantMoveMouse)
MyFuncToSetMousePosition(io.MousePos.x, io.MousePos.y);
ImGui::NewFrame();
In a setup when you may not have easy control over the mouse cursor (e.g. uSynergy doesn't expose changing remote mouse cursor),
you might want to set a boolean to request ignoring your other external mouse positions until they move again.
API BREAKING CHANGES
@ -266,7 +299,7 @@
Q: How can I help?
A: - If you are experienced enough with ImGui and with C/C++, look at the todo list and see how you want/can help!
- Become a Patron/donate. Convince your company to become a Patron or provide serious funding for development time.
- Become a Patron/donate! Convince your company to become a Patron or provide serious funding for development time! See http://www.patreon.com/imgui
Q: How do I update to a newer version of ImGui?
A: Overwrite the following files:
@ -480,9 +513,9 @@
- window/tooltip: allow to set the width of a tooltip to allow TextWrapped() etc. while keeping the height automatic.
- window: increase minimum size of a window with menus or fix the menu rendering so that it doesn't look odd.
- draw-list: maintaining bounding box per command would allow to merge draw command when clipping isn't relied on (typical non-scrolling window or non-overflowing column would merge with previous command).
!- scrolling: allow immediately effective change of scroll if we haven't appended items yet
!- scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet
- splitter/separator: formalize the splitter idiom into an official api (we want to handle n-way split) (#319)
- widgets: display mode: widget-label, label-widget (aligned on column or using fixed size), label-newline-tab-widget etc.
- widgets: display mode: widget-label, label-widget (aligned on column or using fixed size), label-newline-tab-widget etc. (#395)
- widgets: clean up widgets internal toward exposing everything.
- widgets: add disabled and read-only modes (#211)
- main: considering adding an Init() function? some constructs are awkward in the implementation because of the lack of them.
@ -532,7 +565,6 @@
- popups: border options. richer api like BeginChild() perhaps? (#197)
- tooltip: tooltip that doesn't fit in entire screen seems to lose their "last prefered button" and may teleport when moving mouse
- menus: local shortcuts, global shortcuts (#456, #126)
- menus: icons
- menus: menubars: some sort of priority / effect of main menu-bar on desktop size?
- menus: calling BeginMenu() twice with a same name doesn't seem to append nicely
- statusbar: add a per-window status bar helper similar to what menubar does.
@ -563,6 +595,7 @@
- textwrapped: figure out better way to use TextWrapped() in an always auto-resize context (tooltip, etc.) (#249)
- settings: write more decent code to allow saving/loading new fields
- settings: api for per-tool simple persistent data (bool,int,float,columns sizes,etc.) in .ini file
- stb: add defines to disable stb implementations
- style: add window shadows.
- style/optimization: store rounded corners in texture to use 1 quad per corner (filled and wireframe) to lower the cost of rounding.
- style: color-box not always square?
@ -570,7 +603,7 @@
- style: try to make PushStyleVar() more robust to incorrect parameters (to be more friendly to edit & continues situation).
- style/opt: PopStyleVar could be optimized by having GetStyleVar returns the type, using a table mapping stylevar enum to data type.
- style: global scale setting.
- style: WindowPadding needs to be EVEN needs the 0.5 multiplier probably have a subtle effect on clip rectangle
- style: WindowPadding needs to be EVEN as the 0.5 multiplier used on this value probably have a subtle effect on clip rectangle
- text: simple markup language for color change?
- font: dynamic font atlas to avoid baking huge ranges into bitmap and make scaling easier.
- font: small opt: for monospace font (like the defalt one) we can trim IndexXAdvance as long as trailing value is == FallbackXAdvance
@ -583,6 +616,7 @@
- log: let user copy any window content to clipboard easily (CTRL+C on windows? while moving it? context menu?). code is commented because it fails with multiple Begin/End pairs.
- filters: set a current filter that tree node can automatically query to hide themselves
- filters: handle wildcards (with implicit leading/trailing *), regexps
- filters: fuzzy matches (may use code at blog.forrestthewoods.com/4cffeed33fdb)
- shortcuts: add a shortcut api, e.g. parse "&Save" and/or "Save (CTRL+S)", pass in to widgets or provide simple ways to use (button=activate, input=focus)
!- keyboard: tooltip & combo boxes are messing up / not honoring keyboard tabbing
- keyboard: full keyboard navigation and focus. (#323)