This commit is contained in:
gingerBill
2024-06-06 23:55:54 +01:00
3 changed files with 130 additions and 5 deletions

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@@ -7,7 +7,6 @@ import "core:compress"
import "core:mem"
import "base:intrinsics"
import "base:runtime"
@(require) import "core:fmt"
Error :: image.Error
Image :: image.Image
@@ -19,6 +18,101 @@ RGBA_Pixel :: image.RGBA_Pixel
FILE_HEADER_SIZE :: 14
INFO_STUB_SIZE :: FILE_HEADER_SIZE + size_of(image.BMP_Version)
save_to_buffer :: proc(output: ^bytes.Buffer, img: ^Image, options := Options{}, allocator := context.allocator) -> (err: Error) {
context.allocator = allocator
if img == nil {
return .Invalid_Input_Image
}
if output == nil {
return .Invalid_Output
}
pixels := img.width * img.height
if pixels == 0 || pixels > image.MAX_DIMENSIONS {
return .Invalid_Input_Image
}
// While the BMP spec (and our loader) support more fanciful image types,
// `bmp.save` supports only 3 and 4 channel images with a bit depth of 8.
if img.depth != 8 || img.channels < 3 || img.channels > 4 {
return .Invalid_Input_Image
}
if img.channels * pixels != len(img.pixels.buf) {
return .Invalid_Input_Image
}
// Calculate and allocate size.
header_size := u32le(image.BMP_Version.V3)
total_header_size := header_size + 14 // file header = 14
pixel_count_bytes := u32le(align4(img.width * img.channels) * img.height)
header := image.BMP_Header{
// File header
magic = .Bitmap,
size = total_header_size + pixel_count_bytes,
_res1 = 0,
_res2 = 0,
pixel_offset = total_header_size,
// V3
info_size = .V3,
width = i32le(img.width),
height = i32le(img.height),
planes = 1,
bpp = u16le(8 * img.channels),
compression = .RGB,
image_size = pixel_count_bytes,
pels_per_meter = {2835, 2835}, // 72 DPI
colors_used = 0,
colors_important = 0,
}
written := 0
if resize(&output.buf, int(header.size)) != nil {
return .Unable_To_Allocate_Or_Resize
}
header_bytes := transmute([size_of(image.BMP_Header)]u8)header
written += int(total_header_size)
copy(output.buf[:], header_bytes[:written])
switch img.channels {
case 3:
row_bytes := img.width * img.channels
row_padded := align4(row_bytes)
pixels := mem.slice_data_cast([]RGB_Pixel, img.pixels.buf[:])
for y in 0..<img.height {
row_offset := row_padded * (img.height - y - 1) + written
for x in 0..<img.width {
pix_offset := 3 * x
output.buf[row_offset + pix_offset + 0] = pixels[0].b
output.buf[row_offset + pix_offset + 1] = pixels[0].g
output.buf[row_offset + pix_offset + 2] = pixels[0].r
pixels = pixels[1:]
}
}
case 4:
row_bytes := img.width * img.channels
pixels := mem.slice_data_cast([]RGBA_Pixel, img.pixels.buf[:])
for y in 0..<img.height {
row_offset := row_bytes * (img.height - y - 1) + written
for x in 0..<img.width {
pix_offset := 4 * x
output.buf[row_offset + pix_offset + 0] = pixels[0].b
output.buf[row_offset + pix_offset + 1] = pixels[0].g
output.buf[row_offset + pix_offset + 2] = pixels[0].r
output.buf[row_offset + pix_offset + 3] = pixels[0].a
pixels = pixels[1:]
}
}
}
return
}
load_from_bytes :: proc(data: []byte, options := Options{}, allocator := context.allocator) -> (img: ^Image, err: Error) {
ctx := &compress.Context_Memory_Input{
input_data = data,

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@@ -2,6 +2,7 @@
package core_image_bmp
import "core:os"
import "core:bytes"
load :: proc{load_from_file, load_from_bytes, load_from_context}
@@ -16,4 +17,18 @@ load_from_file :: proc(filename: string, options := Options{}, allocator := cont
} else {
return nil, .Unable_To_Read_File
}
}
save :: proc{save_to_buffer, save_to_file}
save_to_file :: proc(output: string, img: ^Image, options := Options{}, allocator := context.allocator) -> (err: Error) {
context.allocator = allocator
out := &bytes.Buffer{}
defer bytes.buffer_destroy(out)
save_to_buffer(out, img, options) or_return
write_ok := os.write_entire_file(output, out.buf[:])
return nil if write_ok else .Unable_To_Write_File
}

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@@ -2327,10 +2327,6 @@ run_bmp_suite :: proc(t: ^testing.T, suite: []Test) {
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.
qoi_file := strings.concatenate({TEST_SUITE_PATH_BMP, "/", file.file, ".qoi"}, context.allocator)
defer delete(qoi_file)
qoi.save(qoi_file, img)
pixels := bytes.buffer_to_bytes(&img.pixels)
dims := Dims{img.width, img.height, img.channels, img.depth}
@@ -2338,6 +2334,26 @@ run_bmp_suite :: proc(t: ^testing.T, suite: []Test) {
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)
// Save to BMP file in memory
buf: bytes.Buffer
save_err := bmp.save(&buf, img)
testing.expectf(t, save_err == nil, "expected saving to BMP in memory not to raise error, got %v", save_err)
// Reload BMP from memory
reload_img, reload_err := bmp.load(buf.buf[:])
testing.expectf(t, reload_err == nil, "expected reloading BMP from memory not to raise error, got %v", reload_err)
testing.expect(t, img.width == reload_img.width && img.height == reload_img.height, "expected saved BMP to have the same dimensions")
testing.expect(t, img.channels == reload_img.channels && img.depth == reload_img.depth, "expected saved BMP to have the same dimensions")
reload_pixels := bytes.buffer_to_bytes(&reload_img.pixels)
reload_hash := hash.crc32(reload_pixels)
testing.expectf(t, img_hash == reload_hash, "expected saved BMP to have the same pixel hash (%08x), got %08x", img_hash, reload_hash)
bytes.buffer_destroy(&buf)
bmp.destroy(reload_img)
}
bmp.destroy(img)
}