Implement .alpha_add_if_missing for JPEG

This commit is contained in:
Jeroen van Rijn
2025-09-09 14:51:16 +02:00
parent 737c87a726
commit 7b3ca701e0
2 changed files with 95 additions and 29 deletions

View File

@@ -927,9 +927,9 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
cbcr_pixel_column := k / luma_h_sampling_factor + 4 * h
cbcr_pixel := cbcr_pixel_row * BLOCK_SIZE + cbcr_pixel_column
r := cast(i16)math.clamp(cast(f32)y_blk[.Y][i] + 1.402 * cast(f32)cbcr_blk[.Cr][cbcr_pixel] + 128, 0, 255)
g := cast(i16)math.clamp(cast(f32)y_blk[.Y][i] - 0.344 * cast(f32)cbcr_blk[.Cb][cbcr_pixel] - 0.714 * cast(f32)cbcr_blk[.Cr][cbcr_pixel] + 128, 0, 255)
b := cast(i16)math.clamp(cast(f32)y_blk[.Y][i] + 1.772 * cast(f32)cbcr_blk[.Cb][cbcr_pixel] + 128, 0, 255)
r := cast(i16)clamp(cast(f32)y_blk[.Y][i] + 1.402 * cast(f32)cbcr_blk[.Cr][cbcr_pixel] + 128, 0, 255)
g := cast(i16)clamp(cast(f32)y_blk[.Y][i] - 0.344 * cast(f32)cbcr_blk[.Cb][cbcr_pixel] - 0.714 * cast(f32)cbcr_blk[.Cr][cbcr_pixel] + 128, 0, 255)
b := cast(i16)clamp(cast(f32)y_blk[.Y][i] + 1.772 * cast(f32)cbcr_blk[.Cb][cbcr_pixel] + 128, 0, 255)
y_blk[.Y][i] = r
y_blk[.Cb][i] = g
@@ -941,28 +941,94 @@ load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.a
}
}
if .alpha_add_if_missing in options {
img.channels += 1
}
if resize(&img.pixels.buf, img.width * img.height * img.channels) != nil {
return img, .Unable_To_Allocate_Or_Resize
}
out := mem.slice_data_cast([]image.RGB_Pixel, img.pixels.buf[:])
for y in 0..<img.height {
mcu_row := y / BLOCK_SIZE
pixel_row := y % BLOCK_SIZE
for x in 0..<img.width {
mcu_col := x / BLOCK_SIZE
pixel_col := x % BLOCK_SIZE
mcu_idx := mcu_row * block_width + mcu_col
pixel_idx := pixel_row * BLOCK_SIZE + pixel_col
switch img.channels {
case 1:
out_idx := 0
for y in 0..<img.height {
mcu_row := y / BLOCK_SIZE
pixel_row := y % BLOCK_SIZE
for x in 0..<img.width {
mcu_col := x / BLOCK_SIZE
pixel_col := x % BLOCK_SIZE
mcu_idx := mcu_row * block_width + mcu_col
pixel_idx := pixel_row * BLOCK_SIZE + pixel_col
if img.channels == 3 {
out[y * img.width + x] = {
img.pixels.buf[out_idx] = cast(byte)blocks[mcu_idx][.Y][pixel_idx]
out_idx += 1
}
}
case 2:
out := mem.slice_data_cast([]image.GA_Pixel, img.pixels.buf[:])
out_idx := 0
for y in 0..<img.height {
mcu_row := y / BLOCK_SIZE
pixel_row := y % BLOCK_SIZE
for x in 0..<img.width {
mcu_col := x / BLOCK_SIZE
pixel_col := x % BLOCK_SIZE
mcu_idx := mcu_row * block_width + mcu_col
pixel_idx := pixel_row * BLOCK_SIZE + pixel_col
out[out_idx] = {
cast(byte)blocks[mcu_idx][.Y][pixel_idx],
255, // Alpha
}
out_idx += 1
}
}
case 3:
out := mem.slice_data_cast([]image.RGB_Pixel, img.pixels.buf[:])
out_idx := 0
for y in 0..<img.height {
mcu_row := y / BLOCK_SIZE
pixel_row := y % BLOCK_SIZE
for x in 0..<img.width {
mcu_col := x / BLOCK_SIZE
pixel_col := x % BLOCK_SIZE
mcu_idx := mcu_row * block_width + mcu_col
pixel_idx := pixel_row * BLOCK_SIZE + pixel_col
out[out_idx] = {
cast(byte)blocks[mcu_idx][.Y][pixel_idx],
cast(byte)blocks[mcu_idx][.Cb][pixel_idx],
cast(byte)blocks[mcu_idx][.Cr][pixel_idx],
}
} else {
img.pixels.buf[y * img.width + x] = cast(byte)blocks[mcu_idx][.Y][pixel_idx]
out_idx += 1
}
}
case 4:
out := mem.slice_data_cast([]image.RGBA_Pixel, img.pixels.buf[:])
out_idx := 0
for y in 0..<img.height {
mcu_row := y / BLOCK_SIZE
pixel_row := y % BLOCK_SIZE
for x in 0..<img.width {
mcu_col := x / BLOCK_SIZE
pixel_col := x % BLOCK_SIZE
mcu_idx := mcu_row * block_width + mcu_col
pixel_idx := pixel_row * BLOCK_SIZE + pixel_col
out[out_idx] = {
cast(byte)blocks[mcu_idx][.Y][pixel_idx],
cast(byte)blocks[mcu_idx][.Cb][pixel_idx],
cast(byte)blocks[mcu_idx][.Cr][pixel_idx],
255, // Alpha
}
out_idx += 1
}
}
}

View File

@@ -2367,7 +2367,7 @@ Basic_JPG_Tests := []Test{
{
"emblem-1024", {
{Default, nil, {1024, 1024, 3, 8}, 0x_46a29e0f},
// {Alpha_Add, nil, {1024, 1024, 4, 8}, 0x_46a29e0f},
{Alpha_Add, nil, {1024, 1024, 4, 8}, 0x_cae2d532},
},
},
{
@@ -2394,21 +2394,21 @@ run_jpg_suite :: proc(t: ^testing.T, suite: []Test) {
passed := (test.expected_error == nil && err == nil) || (test.expected_error == err)
testing.expectf(t, passed, "%q failed to load with error %v.", file.file, err)
if err == nil { // No point in running the other tests if it didn't load.
pixels := bytes.buffer_to_bytes(&img.pixels)
// No point in running the other tests if it didn't load.
(err == nil) or_continue
dims := Dims{img.width, img.height, img.channels, img.depth}
testing.expectf(t, test.dims == dims, "%v has %v, expected: %v.", file.file, dims, test.dims)
pixels := bytes.buffer_to_bytes(&img.pixels)
dims := Dims{img.width, img.height, img.channels, img.depth}
testing.expectf(t, test.dims == dims, "%v has %v, expected: %v.", file.file, dims, test.dims)
img_hash := hash.crc32(pixels)
testing.expectf(t, test.hash == img_hash, "%v test #1's hash is %08x, expected %08x with %v.", file.file, img_hash, test.hash, test.options)
img_hash := hash.crc32(pixels)
testing.expectf(t, test.hash == img_hash, "%v test #1's hash is %08x, expected %08x with %v.", file.file, img_hash, test.hash, test.options)
// Optionally save to BMP file to check file loaded properly during development
when false {
test_bmp := strings.concatenate({TEST_SUITE_PATH_JPG, "/", file.file, ".bmp"}, context.temp_allocator)
save_err := bmp.save(test_bmp, img)
testing.expectf(t, save_err == nil, "expected saving to BMP not to raise error, got %v", save_err)
}
// Optionally save to QOI file to check file loaded properly during development
when false {
test_qoi := strings.concatenate({TEST_SUITE_PATH_JPG, "/", file.file, ".qoi"}, context.temp_allocator)
save_err := qoi.save(test_qoi, img)
testing.expectf(t, save_err == nil, "expected saving to QOI not to raise error, got %v", save_err)
}
}
}