decode_test.go

package tga_test

import (
	"bufio"
	_ "github.com/ftrvxmtrx/tga" // should be the first one, because TGA doesn't have any constant "header"
	"image"
	"image/color"
	"os"
	"testing"

	_ "image/png"
)

type tgaTest struct {
	golden string
	source string
}

var tgaTests = []tgaTest{
	{"bw.png", "cbw8.tga"},
	{"bw.png", "ubw8.tga"},
	{"color.png", "ctc32.tga"},
	{"color.png", "ctc24.tga"},
	{"color.png", "ctc16.tga"},
	{"color.png", "ccm8.tga"},
	{"color.png", "ucm8.tga"},
	{"color.png", "utc32.tga"},
	{"color.png", "utc24.tga"},
	{"color.png", "utc16.tga"},
	{"monochrome16.png", "monochrome16_top_left_rle.tga"},
	{"monochrome16.png", "monochrome16_top_left.tga"},
	{"monochrome8.png", "monochrome8_bottom_left_rle.tga"},
	{"monochrome8.png", "monochrome8_bottom_left.tga"},
	{"rgb24.0.png", "rgb24_bottom_left_rle.tga"},
	{"rgb24.1.png", "rgb24_top_left_colormap.tga"},
	{"rgb24.0.png", "rgb24_top_left.tga"},
	{"rgb32.0.png", "rgb32_bottom_left.tga"},
	{"rgb32.1.png", "rgb32_top_left_rle_colormap.tga"},
	{"rgb32.0.png", "rgb32_top_left_rle.tga"},
}

func decode(filename string) (image.Image, string, error) {
	f, err := os.Open("testdata/" + filename)

	if err != nil {
		return nil, "", err
	}

	defer f.Close()

	return image.Decode(bufio.NewReader(f))
}

func delta(a, b uint32) int {
	if a < b {
		return int(b) - int(a)
	}

	return int(a) - int(b)
}

func equal(c0, c1 color.Color) bool {
	r0, g0, b0, a0 := c0.RGBA()
	r1, g1, b1, a1 := c1.RGBA()

	if a0 == 0 && a1 == 0 {
		return true
	}

	return r0 == r1 && g0 == g1 && b0 == b1 && a0 == a1
}

func TestDecode(t *testing.T) {
loop:

	for _, test := range tgaTests {
		if golden, _, err := decode(test.golden); err != nil {
			t.Errorf("%s: %v", test.golden, err)
		} else if source, format, err := decode(test.source); err != nil {
			t.Errorf("%s: %v", test.source, err)
		} else if format != "tga" {
			t.Errorf("%s: expected tga, got %v", test.source, format)
		} else if !golden.Bounds().Eq(source.Bounds()) {
			t.Errorf("%s: expected bounds %v, got %v", test.source, golden.Bounds(), source.Bounds())
		} else {
			gb := golden.Bounds()

			for x := gb.Min.X; x < gb.Max.X; x++ {
				for y := gb.Min.Y; y < gb.Max.Y; y++ {
					if !equal(golden.At(x, y), source.At(x, y)) {
						t.Errorf("%s: (%d, %d) -- expected %v, got %v", test.source, x, y, golden.At(x, y), source.At(x, y))
						continue loop
					}
				}
			}
		}
	}
}