clay/bindings/odin/README.md
2024-08-30 21:58:08 +12:00

145 lines
7.0 KiB
Markdown

### Odin Language Bindings
This directory contains bindings for the [Odin](odin-lang.org) programming language, as well as an example implementation of the [clay website](https://nicbarker.com/clay) in Odin.
If you haven't taken a look at the [full documentation for clay](https://github.com/nicbarker/clay/blob/main/README.md), it's recommended that you take a look there first to familiarise yourself with the general concepts. This README is abbreviated and applies to using clay in Odin specifically.
The **most notable difference** between the C API and the Odin bindings is the use of if statements to create the scope for declaring child elements. When using the equivalent of the [Element Macros](https://github.com/nicbarker/clay/blob/main/README.md#element-macros):
Special thanks to
- [laytan](https://github.com/laytan)
- [Dudejoe870](https://github.com/Dudejoe870)
- MrStevns from the Odin Discord server
```C
// C form of element macros
CLAY_RECTANGLE(CLAY_ID("SideBar"), CLAY_LAYOUT(.layoutDirection = CLAY_TOP_TO_BOTTOM, .sizing = { .width = CLAY_SIZING_FIXED(300), .height = CLAY_SIZING_GROW() }, .padding = {16, 16}), CLAY_RECTANGLE_CONFIG(.color = COLOR_LIGHT), {
// Child elements here
});
```
```Odin
// Odin form of element macros
if clay.Rectangle(clay.ID("SideBar"), clay.Layout({ layoutDirection = .TOP_TO_BOTTOM, sizing = { width = clay.SizingFixed(300), height = clay.SizingGrow({}) }, padding = {16, 16} }), clay.RectangleConfig({ color = COLOR_LIGHT })) {
// Child elements here
}
```
### Quick Start
1. Download the [clay-odin](link todo) directory and copy it into your project.
```Odin
import clay "clay-odin"
```
2. Ask clay for how much static memory it needs using [clay.MinMemorySize()](https://github.com/nicbarker/clay/blob/main/README.md#clay_minmemorysize), create an Arena for it to use with [clay.CreateArenaWithCapacityAndMemory(minMemorySize, memory)](https://github.com/nicbarker/clay/blob/main/README.md#clay_createarenawithcapacityandmemory), and initialize it with [clay.Initialize(arena)](https://github.com/nicbarker/clay/blob/main/README.md#clay_initialize).
```Odin
minMemorySize: c.uint32_t = clay.MinMemorySize()
memory := make([^]u8, minMemorySize)
arena: clay.Arena = clay.CreateArenaWithCapacityAndMemory(minMemorySize, memory)
```
3. Provide a `measureText(text, config)` proc "c" with [clay.SetMeasureTextFunction(function)](https://github.com/nicbarker/clay/blob/main/README.md#clay_setmeasuretextfunction) so that clay can measure and wrap text.
```Odin
// Example measure text function
measureText :: proc "c" (text: ^clay.String, config: ^clay.TextElementConfig) -> clay.Dimensions {
// clay.TextElementConfig contains members such as fontId, fontSize, letterSpacing etc
// Note: clay.String->chars is not guaranteed to be null terminated
}
// Tell clay how to measure text
clay.SetMeasureTextFunction(measureText)
```
4. **Optional** - Call [clay.SetPointerPosition(pointerPosition)](https://github.com/nicbarker/clay/blob/main/README.md#clay_setpointerposition) if you want to use mouse interactions.
```Odin
// Update internal pointer position for handling mouseover / click / touch events
clay.SetPointerPosition(clay.Vector2{ mousePositionX, mousePositionY })
```
5. Call [clay.BeginLayout(screenWidth, screenHeight)](https://github.com/nicbarker/clay/blob/main/README.md#clay_beginlayout) and declare your layout using the provided macros.
```Odin
COLOR_LIGHT :: clay.Color{224, 215, 210, 255}
COLOR_RED :: clay.Color{168, 66, 28, 255}
COLOR_ORANGE :: clay.Color{225, 138, 50, 255}
// Layout config is just a struct that can be declared statically, or inline
sidebarItemLayout := clay.LayoutConfig {
sizing = {width = clay.SizingGrow({}), height = clay.SizingFixed(50)},
}
// Re-useable components are just normal functions
SidebarItemComponent :: proc(index: u32) {
if clay.Rectangle(clay.IDI("SidebarBlob", index), &sidebarItemLayout, clay.RectangleConfig({color = COLOR_ORANGE})) {}
}
// An example function to begin the "root" of your layout tree
CreateLayout :: proc() -> clay.ClayArray(clay.RenderCommand) {
clay.BeginLayout(windowWidth, windowHeight)
// An example of laying out a UI with a fixed width sidebar and flexible width main content
// NOTE: To create a scope for child components, the Odin api uses `if` with components that have children
if clay.Rectangle(
clay.ID("OuterContainer"),
clay.Layout({sizing = {clay.SizingGrow({}), clay.SizingGrow({})}, padding = {16, 16}, childGap = 16}),
clay.RectangleConfig({color = {250, 250, 255, 255}}),
) {
if clay.Rectangle(
clay.ID("SideBar"),
clay.Layout({layoutDirection = .TOP_TO_BOTTOM, sizing = {width = clay.SizingFixed(300), height = clay.SizingGrow({})}, padding = {16, 16}, childGap = 16}),
clay.RectangleConfig({color = COLOR_LIGHT}),
) {
if clay.Rectangle(
clay.ID("ProfilePictureOuter"),
clay.Layout({sizing = {width = clay.SizingGrow({})}, padding = {16, 16}, childGap = 16, childAlignment = {y = .CENTER}}),
clay.RectangleConfig({color = COLOR_RED}),
) {
if clay.Image(
clay.ID("ProfilePicture"),
clay.Layout({sizing = {width = clay.SizingFixed(60), height = clay.SizingFixed(60)}}),
clay.ImageConfig({imageData = &profilePicture, sourceDimensions = {height = 60, width = 60}}),
) {}
clay.Text(clay.ID("ProfileTitle"), clay.MakeString("Clay - UI Library"), clay.TextConfig({fontSize = 24, textColor = {255, 255, 255, 255}}))
}
// Standard Odin code like loops etc work inside components
for i: u32 = 0; i < 10; i += 1 {
SidebarItemComponent(i)
}
}
if clay.Rectangle(
clay.ID("MainContent"),
clay.Layout({sizing = {width = clay.SizingGrow({}), height = clay.SizingGrow({})}}),
clay.RectangleConfig({color = COLOR_LIGHT}),
) {}
}
// ...
}
```
6. Call [clay.EndLayout(screenWidth, screenHeight)](https://github.com/nicbarker/clay/blob/main/README.md#clay_endlayout) and process the resulting [clay.RenderCommandArray](https://github.com/nicbarker/clay/blob/main/README.md#clay_rendercommandarray) in your choice of renderer.
```Odin
renderCommands: clay.ClayArray(clay.RenderCommand) = clay.EndLayout(windowWidth, windowHeight)
for i: u32 = 0; i < renderCommands.length; i += 1 {
renderCommand := clay.RenderCommandArray_Get(&renderCommands, cast(i32)i)
switch renderCommand.commandType {
case .Rectangle:
{
DrawRectangle(renderCommand.boundingBox, renderCommand.config.rectangleElementConfig.color)
}
// ... Implement handling of other command types
}
}
```
Please see the [full C documentation for clay](https://github.com/nicbarker/clay/blob/main/README.md) for API details. All public C functions and Macros have Odin binding equivalents, generally of the form `CLAY_RECTANGLE` (C) -> `clay.Rectangle` (Odin)