pixfont

https://pkg.go.dev/github.com/pbnjay/pixfont
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pixfont is a lightweight pixel font library for Go that allows text drawing on images using the...
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### Use custom font in Go

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Example of importing and using a custom generated font package.

```go
// file main.go

package main

import (
        "image"
        "image/color"
        "image/png"
        "os"

        "main/minecraftia"
)

func main() {
        img := image.NewRGBA(image.Rect(0, 0, 150, 30))

        minecraftia.Font.DrawString(img, 10, 10, "Hello, World!", color.Black)

        f, _ := os.OpenFile("hello.png", os.O_CREATE|os.O_RDWR, 0644)
        png.Encode(f, img)
}
```

--------------------------------

### Example pixel font character set

Source: https://pkg.go.dev/github.com/pbnjay/pixfont/cmd/fontgen

A sample layout of characters to be used as input for the font generation process.

```text
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789

```

--------------------------------

### Intermediate font text format

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Example of the text representation generated by fontgen for manual review and editing.

```text
		l  [X      ]
		l  [X      ]
		l  [X XX X ]
		l  [X X X X]
		l  [X X X X]
		l  [X X   X]
		l  [ XX   X]
		l  [       ]
		m  [       ]
		m  [       ]
		m  [ XXXX  ]
		m  [ X   X ]
		m  [ X   X ]
		m  [ X   X ]
		m  [ X   X ]
		m  [       ]
```

--------------------------------

### PixFont Rendering and Measurement Methods

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Methods for drawing runes/strings and measuring their dimensions using a PixFont instance.

```go
func (p *PixFont) DrawRune(dr Drawable, x, y int, c rune, clr color.Color) (bool, int)
```

```go
func (p *PixFont) DrawString(dr Drawable, x, y int, s string, clr color.Color) int
```

```go
func (p *PixFont) GetHeight() int
```

```go
func (p *PixFont) MeasureRune(c rune) (bool, int)
```

```go
func (p *PixFont) MeasureString(s string) int
```

```go
func (p *PixFont) SetVariableWidth(isVar bool)
```

--------------------------------

### PixFont Structure and Initialization

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Represents a bitmap font and provides a constructor for creating new instances.

```go
type PixFont struct {
	// contains filtered or unexported fields
}
```

```go
func NewPixFont(w, h uint8, cm map[rune]uint16, d []uint32) *PixFont
```

--------------------------------

### Generate font file command

Source: https://pkg.go.dev/github.com/pbnjay/pixfont/cmd/fontgen

Execute this command to process a pixel font image and output a Go source file.

```bash
./fontgen -img mypixelfont.png -o myfont

```

--------------------------------

### Draw and Measure Strings

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Convenience functions for drawing or measuring strings using the default font.

```go
func DrawString(dr Drawable, x, y int, s string, clr color.Color) int
```

```go
func MeasureString(s string) int
```

--------------------------------

### Define Spacing Variable

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Sets the pixel spacing between letters, defaulting to 1 pixel.

```go
var Spacing = 1
```

--------------------------------

### Draw text on an image

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Basic usage of the pixfont package to draw a string onto an RGBA image and save it as a PNG.

```go
package main

import (
        "image"
        "image/color"
        "image/png"
        "os"

        "github.com/pbnjay/pixfont"
)

func main() {
        img := image.NewRGBA(image.Rect(0, 0, 150, 30))

        pixfont.DrawString(img, 10, 10, "Hello, World!", color.Black)

        f, _ := os.OpenFile("hello.png", os.O_CREATE|os.O_RDWR, 0644)
        png.Encode(f, img)
}
```

--------------------------------

### Drawable Interface

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Interface required for rendering, allowing pixel setting at specific coordinates.

```go
type Drawable interface {
	Set(x, y int, c color.Color)
}
```

--------------------------------

### func (*PixFont) DrawRune

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Displays a single rune using the PixFont.

```APIDOC
## func (p *PixFont) DrawRune(dr Drawable, x, y int, c rune, clr color.Color) (bool, int)

### Description
DrawRune uses this PixFont to display a single rune in the provided color and position in Drawable. The x,y position represents the top-left corner of the rune.

### Parameters
- **dr** (Drawable) - The surface to draw on.
- **x** (int) - The x-coordinate.
- **y** (int) - The y-coordinate.
- **c** (rune) - The rune to draw.
- **clr** (color.Color) - The color to use.

### Returns
- **bool** - True if the rune was found and drawn.
- **int** - The number of pixels to advance.
```

--------------------------------

### func NewPixFont

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Creates a new PixFont instance.

```APIDOC
## func NewPixFont(w, h uint8, cm map[rune]uint16, d []uint32) *PixFont

### Description
NewPixFont creates a new PixFont with the provided character width/height and character map of offsets into a packed uint32 array of bits.

### Parameters
- **w** (uint8) - Character width.
- **h** (uint8) - Character height.
- **cm** (map[rune]uint16) - Character map of offsets.
- **d** ([]uint32) - Packed uint32 array of bits.

### Returns
- ***PixFont** - A pointer to the newly created PixFont.
```

--------------------------------

### StringDrawable Implementation

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Implements the Drawable interface to render pixel fonts as text strings.

```go
type StringDrawable struct {
	// contains filtered or unexported fields
}
```

```go
func (s *StringDrawable) PrefixString(p string) string
```

```go
func (s *StringDrawable) Set(x, y int, c color.Color)
```

```go
func (s *StringDrawable) String() string
```

--------------------------------

### Generate custom pixel font

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Commands to generate a pixel font from a source image using the fontgen tool.

```bash
$ ./fontgen -x=1 -y=20 -h=8 -a="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" -img minecraftia.png -o minecraftia
```

```bash
$ ./fontgen -x=1 -y=20 -h=8 -a="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" -img minecraftia.png > minecraftia.txt
```

--------------------------------

### Edit and generate font from text

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Commands to regenerate a font after manually editing the intermediate text file.

```bash
$ ./fontgen -x=1 -y=20 -h=8 -a="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklnopqrstuvwxyz0123456789" -img minecraftia.png > minecraftia.txt
$ vim minecraftia.txt
```

```bash
$ ./fontgen -txt minecraftia.txt -o minecraftia
```

--------------------------------

### Default Font Variable

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

The DefaultFont variable is used by the convenience method DrawString and is initialized to the Public Domain 8x8 fixed font.

```go
var DefaultFont = Font8x8
```

--------------------------------

### func DrawString

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Draws a string using the DefaultFont onto a Drawable surface.

```APIDOC
## func DrawString(dr Drawable, x, y int, s string, clr color.Color) int

### Description
DrawString is a convenience method that calls DrawString using the DefaultFont.

### Parameters
- **dr** (Drawable) - The surface to draw on.
- **x** (int) - The x-coordinate.
- **y** (int) - The y-coordinate.
- **s** (string) - The string to draw.
- **clr** (color.Color) - The color to use for drawing.

### Returns
- **int** - The total pixel advance used by the string.
```

--------------------------------

### Font8x8 Definition

Source: https://pkg.go.dev/github.com/pbnjay/pixfont

Font8x8 is a fixed-width 8x8 pixel font available in the Public Domain.

```go
var Font8x8 = &PixFont{
	8, 8,
	eightMap,
	eightData,
	8,
}
```
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