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Add BC7 compression + restructure DDS testing
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@xypwn
xypwn committed Apr 3, 2024
1 parent f3102b8 commit 43deb02
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Showing 21 changed files with 563 additions and 76 deletions.
48 changes: 6 additions & 42 deletions dds/color.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -5,27 +5,27 @@ func mapBits1To8(x uint16) uint8 {
}

func mapBits2To8(x uint16) uint8 {
return uint8((x * 340) >> 2)
return uint8(x<<6 | x<<4 | x<<2 | x)
}

func mapBits3To8(x uint16) uint8 {
return uint8((x * 292) >> 3)
return uint8(x<<5 | x<<2 | x>>1)
}

func mapBits4To8(x uint16) uint8 {
return uint8(x * 17)
return uint8(x<<4 | x)
}

func mapBits5To8(x uint16) uint8 {
return uint8((x*527 + 23) >> 6)
return uint8(x<<3 | x>>2)
}

func mapBits6To8(x uint16) uint8 {
return uint8((x*259 + 33) >> 6)
return uint8(x<<2 | x>>4)
}

func mapBits7To8(x uint16) uint8 {
return uint8((x * 129) >> 6)
return uint8(x<<1 | x>>6)
}

func colorR5G6B5ToRGB(x uint16) (uint8, uint8, uint8) {
Expand All @@ -34,39 +34,3 @@ func colorR5G6B5ToRGB(x uint16) (uint8, uint8, uint8) {
b5 := x & 0b0000_0000_0001_1111
return mapBits5To8(r5), mapBits6To8(g6), mapBits5To8(b5)
}

// Program to brute force the mapBitsXTo8 parameters
/*
package main
import (
"fmt"
"math"
)
func main() {
const startBits = 5
const rsh = 6
const n = 1 << startBits
for a := 0; a < 800; a++ {
for b := 0; b < 128; b++ {
bad := false
for i := 0; i < n; i++ {
expect := int(math.Floor(float64(i)*255/(n-1) + 0.5))
try := (i*a + b) >> rsh
if try != expect {
bad = true
break
}
}
if !bad {
fmt.Printf("mapBits%vTo8(x uint16) uint8 {\n", startBits)
fmt.Printf(" return uint8((x*%v + %v) >> %v)\n", a, b, rsh)
fmt.Printf("}\n")
}
}
}
}
*/
7 changes: 5 additions & 2 deletions dds/dds.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -114,8 +114,11 @@ func DecodeInfo(r io.Reader) (Info, error) {
case DXGIFormatBC5UNorm:
info.ColorModel = color.NRGBAModel
info.Decompress = Decompress3Dc
case DXGIFormatBC7UNorm, DXGIFormatBC7UNormSRGB:
return Info{}, errors.New("BC7 compression unsupported")
case DXGIFormatBC7UNorm:
info.ColorModel = color.NRGBAModel
info.Decompress = DecompressBC7
case DXGIFormatBC7UNormSRGB:
return Info{}, errors.New("BC7 SRGB compression unsupported")
default:
return Info{}, fmt.Errorf("unsupported DXGI format: %v", dx10.DXGIFormat)
}
Expand Down
93 changes: 65 additions & 28 deletions dds/dds_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ import (
"encoding/binary"
"encoding/hex"
"image"
"image/png"
_ "image/png"
"os"
"testing"

Expand Down Expand Up @@ -34,47 +34,84 @@ func testImageChecksum(t *testing.T, img image.Image, expectedSumHexStr string)
}
}

func testDDSImage(t *testing.T, path string, checksumHex string, save bool) {
r, err := os.Open(path)
if err != nil {
t.Fatal(err)
}
func checkDDSImageEqual(t *testing.T, ddsPath, comparePath string, allowDelta int64) {
var ddsImg image.Image
var compareImg image.Image

img, name, err := image.Decode(r)
if err != nil {
t.Fatal(err)
}
{
r, err := os.Open(ddsPath)
if err != nil {
t.Fatal(err)
}
defer r.Close()

var name string
ddsImg, name, err = image.Decode(r)
if err != nil {
t.Fatal(err)
}

if name != "dds" {
t.Fatalf("expected \"dds\" image, but got \"%v\"", name)
if name != "dds" {
t.Fatalf("expected \"dds\" image, but got \"%v\"", name)
}
}

if save {
w, err := os.Create("out.png")
{
r, err := os.Open(comparePath)
if err != nil {
t.Fatal(err)
}
if err := png.Encode(w, img); err != nil {
defer r.Close()

compareImg, _, err = image.Decode(r)
if err != nil {
t.Fatal(err)
}
}

testImageChecksum(t, img, checksumHex)
if ddsImg.Bounds() != compareImg.Bounds() {
t.Fatal("DDS image and compare image must have the same bounds")
}

for y := ddsImg.Bounds().Min.Y; y < ddsImg.Bounds().Max.Y; y++ {
for x := ddsImg.Bounds().Min.X; y < ddsImg.Bounds().Max.X; y++ {
r0, g0, b0, a0 := ddsImg.At(x, y).RGBA()
r1, g1, b1, a1 := compareImg.At(x, y).RGBA()
dR, dG, dB, dA := int64(r1)-int64(r0), int64(g1)-int64(g0), int64(b1)-int64(b0), int64(a1)-int64(a0)
if dR < 0 {
dR = -dR
}
if dG < 0 {
dG = -dG
}
if dB < 0 {
dB = -dB
}
if dA < 0 {
dA = -dA
}
// Allow slight deviations due to different mappings
if dR > allowDelta || dG > allowDelta || dB > allowDelta || dA > allowDelta {
t.Fatalf("DDS image and compare image are not equal (x=%v, y=%v: dds: %v, compare: %v)", x, y, [4]uint32{r0, g0, b0, a0}, [4]uint32{r1, g1, b1, a1})
}
}
}
}

func TestDDSImage(t *testing.T) {
testDDSImage(t, "testimg-bc1.dds", "079b4749d42c07f36bc6daa7bb2f5476beca92f38f4798e4c98e86624a50d931", false)
testDDSImage(t, "testimg-bc3.dds", "b8127ddcbddd112914bf0a70c8a7116ec311d3f17e5773177ccc403ff610ca6a", false)
testDDSImage(t, "testimg-bc4.dds", "26587032b504ca06724a35e9cb437895ce6e6e491d3a6245089cd396888224c2", false)
testDDSImage(t, "testimg-bc5.dds", "449e0bb16584f6174218c10d7401bd79feff5cffe71d7c28b9fea16d5e6e4daa", false)
testDDSImage(t, "testimg-rgb8.dds", "17a28fb962d0277240418a5f14fb5b14b1c528fcda019d0c9f69de2426886402", false)
testDDSImage(t, "testimg-rgba8.dds", "17a28fb962d0277240418a5f14fb5b14b1c528fcda019d0c9f69de2426886402", false)
testDDSImage(t, "testimg-r5g6r5.dds", "dda7c4a7d79e36aa746929c88de36311797d6c64ef35e3b604366f7d8ee9dafc", false)
testDDSImage(t, "testimg-l8.dds", "b2c503dfcccd074d59dd1fa344053250bec3c84eee8b689617097c8c90e28bbe", false)
checkDDSImageEqual(t, "testimgs/dds/testimg-bc1.dds", "testimgs/compare/testimg-bc1.png", 257)
checkDDSImageEqual(t, "testimgs/dds/testimg-bc3.dds", "testimgs/compare/testimg-bc3.png", 257)
checkDDSImageEqual(t, "testimgs/dds/testimg-bc4.dds", "testimgs/compare/testimg-bc4.png", 257)
checkDDSImageEqual(t, "testimgs/dds/testimg-bc5.dds", "testimgs/compare/testimg-bc5.png", 257)
checkDDSImageEqual(t, "testimgs/dds/testimg-bc7.dds", "testimgs/compare/testimg-bc7.png", 0)
checkDDSImageEqual(t, "testimgs/dds/testimg-rgb8.dds", "testimgs/compare/testimg.png", 0)
checkDDSImageEqual(t, "testimgs/dds/testimg-rgba8.dds", "testimgs/compare/testimg.png", 0)
checkDDSImageEqual(t, "testimgs/dds/testimg-r5g6r5.dds", "testimgs/compare/testimg-r5g6r5.png", 0)
checkDDSImageEqual(t, "testimgs/dds/testimg-l8.dds", "testimgs/compare/testimg-l8.png", 0)
}

func TestDDSMipMaps(t *testing.T) {
r, err := os.Open("testimg-bc3.dds")
r, err := os.Open("testimgs/dds/testimg-bc3.dds")
if err != nil {
t.Fatal(err)
}
Expand All @@ -92,7 +129,7 @@ func TestDDSMipMaps(t *testing.T) {
t.Fatalf("expected 10 mipmap, but got %v", len(dds.Images[0].MipMaps))
}

testImageChecksum(t, dds.Images[0].MipMaps[0], "b8127ddcbddd112914bf0a70c8a7116ec311d3f17e5773177ccc403ff610ca6a")
testImageChecksum(t, dds.Images[0].MipMaps[1], "293c4be8a6c13bdedf3b8ff5f81d5fc8fe82c468277737f32e6e6035cd4169a6")
testImageChecksum(t, dds.Images[0].MipMaps[2], "1a7ab642e80bf2a3634b5df75b2b0d1ce4c15047626115a3f33c9b7db8a21ae3")
testImageChecksum(t, dds.Images[0].MipMaps[0], "17a28fb962d0277240418a5f14fb5b14b1c528fcda019d0c9f69de2426886402")
testImageChecksum(t, dds.Images[0].MipMaps[1], "dacf23b70aa1422e232c2d496c6cf845e57f3c9e3132823edb603787e843800c")
testImageChecksum(t, dds.Images[0].MipMaps[2], "db0772a48c675b7e1ee58a85c0b7438f8fb3b9b12bd5040fc5cdadb9d44b2324")
}
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