misc.go

// Copyright 2012 The go-gl Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package gltext

import (
	"image"
)

// toRGBA translates the given image to RGBA format if necessary.
// Optionally scales it by the given amount.
func toRGBA(src image.Image, scale int) *image.RGBA {
	if scale < 1 {
		scale = 1
	}

	dst, ok := src.(*image.RGBA)
	if ok && scale == 1 {
		return dst
	}

	// Scale image to match new size.
	ib := src.Bounds()
	rect := image.Rect(0, 0, ib.Dx()*scale, ib.Dy()*scale)

	if !ok {
		// Image is not RGBA, so we create it.
		dst = image.NewRGBA(rect)
	}

	for sy := 0; sy < ib.Dy(); sy++ {
		for sx := 0; sx < ib.Dx(); sx++ {
			dx := sx * scale
			dy := sy * scale
			pixel := src.At(sx, sy)

			for scy := 0; scy < scale; scy++ {
				for scx := 0; scx < scale; scx++ {
					dst.Set(dx+scx, dy+scy, pixel)
				}
			}
		}
	}

	return dst
}