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Updates to match new primary repo.

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This commit is contained in:
iegod
2023-10-02 14:38:49 -04:00
parent db5da9bb48
commit 8f7b16a9ae
13 changed files with 545 additions and 229 deletions
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56
gradient.go
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@@ -3,6 +3,13 @@ package main
import (
"image"
"image/color"
"github.com/hajimehoshi/ebiten/v2"
)
const (
GRAD_IDX_TOP = 0
GRAD_IDX_BOTTOM = 1
)
func HexToRGBA(hexcolor int) color.RGBA {
@@ -14,13 +21,36 @@ func HexToRGBA(hexcolor int) color.RGBA {
}
}
// performs linear gradient fill on target image for the background from top to bottom colors
func FillGradient(target *image.RGBA, width int, height int, top, bottom color.RGBA) {
type Gradient struct {
Scene *ebiten.Image //our resultant image
target *image.RGBA //raw pixel array
width int
height int
colors []color.RGBA //gradient boundary colors
}
for y := 0; y < height; y++ {
func NewGradient(width, height int) *Gradient {
return &Gradient{
Scene: ebiten.NewImage(width, height),
target: image.NewRGBA(image.Rect(0, 0, width, height)),
width: width,
height: height,
colors: []color.RGBA{HexToRGBA(0xFFFFFF), HexToRGBA(0x000000)},
}
}
func (g *Gradient) SetColors(top, bottom color.RGBA) {
g.colors[GRAD_IDX_TOP] = top
g.colors[GRAD_IDX_BOTTOM] = bottom
g.fillCurrent()
}
// performs linear fill on the currently set gradient values, top to bottom (0 to 1)
func (g *Gradient) fill(top, bottom color.RGBA) {
for y := 0; y < g.height; y++ {
//the percent of our transition informs our blending
percentIn := float64(y) / float64(height)
percentIn := float64(y) / float64(g.height)
//compute top and bottom blend values as factor of percentage
pTopR := float64(top.R) * (1 - percentIn)
@@ -32,12 +62,18 @@ func FillGradient(target *image.RGBA, width int, height int, top, bottom color.R
pBottomB := float64(bottom.B) * (percentIn)
//perform blending on per pixel row basis
for x := 0; x < width; x++ {
pixelIndex := 4 * (width*y + x)
target.Pix[pixelIndex] = uint8(pTopR + pBottomR)
target.Pix[pixelIndex+1] = uint8(pTopG + pBottomG)
target.Pix[pixelIndex+2] = uint8(pTopB + pBottomB)
target.Pix[pixelIndex+3] = 0xff
for x := 0; x < g.width; x++ {
pixelIndex := 4 * (g.width*y + x)
g.target.Pix[pixelIndex] = uint8(pTopR + pBottomR)
g.target.Pix[pixelIndex+1] = uint8(pTopG + pBottomG)
g.target.Pix[pixelIndex+2] = uint8(pTopB + pBottomB)
g.target.Pix[pixelIndex+3] = 0xff
}
}
g.Scene.WritePixels(g.target.Pix)
}
// gradient on currently set colors
func (g *Gradient) fillCurrent() {
g.fill(g.colors[GRAD_IDX_TOP], g.colors[GRAD_IDX_BOTTOM])
}