Merge pull request #1981 from benoitjacquier/master

TGA loader

3 files changed, 299 insertions, 5 deletions

diff --git a/core/compress/common.odin b/core/compress/common.odin
index f4e378269..b42cbefff 100644
--- a/core/compress/common.odin
+++ b/core/compress/common.odin
@@ -295,6 +295,24 @@ peek_data_from_memory :: #force_inline proc(z: ^Context_Memory_Input, $T: typeid
 }
 
 @(optimization_mode="speed")
+peek_data_at_offset_from_memory :: #force_inline proc(z: ^Context_Memory_Input, $T: typeid, #any_int offset: int) -> (res: T, err: io.Error) {
+	size :: size_of(T)
+
+	#no_bounds_check {
+		if len(z.input_data) >= size + offset {
+			buf := z.input_data[offset:][:size]
+			return (^T)(&buf[0])^, .None
+		}
+	}
+
+	if len(z.input_data) == 0 {
+		return T{}, .EOF
+	} else {
+		return T{}, .Short_Buffer
+	}
+}
+
+@(optimization_mode="speed")
 peek_data_from_stream :: #force_inline proc(z: ^Context_Stream_Input, $T: typeid) -> (res: T, err: io.Error) {
 	size :: size_of(T)
 
@@ -321,7 +339,44 @@ peek_data_from_stream :: #force_inline proc(z: ^Context_Stream_Input, $T: typeid
 	return res, .None
 }
 
-peek_data :: proc{peek_data_from_memory, peek_data_from_stream}
+@(optimization_mode="speed")
+peek_data_at_offset_from_stream :: #force_inline proc(z: ^Context_Stream_Input, $T: typeid, #any_int offset: int) -> (res: T, err: io.Error) {
+	size :: size_of(T)
+
+	// Get current position to return to.
+	cur_pos, e1 := z.input->impl_seek(0, .Current)
+	if e1 != .None {
+		return T{}, e1
+	}
+
+	// Seek to offset.
+	pos, e2 := z.input->impl_seek(offset, .Start)
+	if e2 != .None {
+		return T{}, e2
+	}
+
+	r, e3 := io.to_reader_at(z.input)
+	if !e3 {
+		return T{}, .Empty
+	}
+	when size <= 128 {
+		b: [size]u8
+	} else {
+		b := make([]u8, size, context.temp_allocator)
+	}
+	_, e4 := io.read_at(r, b[:], pos)
+	if e4 != .None {
+		return T{}, .Empty
+	}
+
+	// Return read head to original position.
+	z.input->impl_seek(cur_pos, .Start)
+
+	res = (^T)(&b[0])^
+	return res, .None
+}
+
+peek_data :: proc{peek_data_from_memory, peek_data_from_stream, peek_data_at_offset_from_memory, peek_data_at_offset_from_stream}
 
 
 
diff --git a/core/image/common.odin b/core/image/common.odin
index 31f622d2b..c79344445 100644
--- a/core/image/common.odin
+++ b/core/image/common.odin
@@ -46,7 +46,7 @@ Image :: struct {
 	height:        int,
 	channels:      int,
 	depth:         int, // Channel depth in bits, typically 8 or 16
-	pixels:        bytes.Buffer,
+	pixels:        bytes.Buffer `fmt:"-"`,
 	/*
 		Some image loaders/writers can return/take an optional background color.
 		For convenience, we return them as u16 so we don't need to switch on the type
@@ -61,6 +61,7 @@ Image_Metadata :: union #shared_nil {
 	^Netpbm_Info,
 	^PNG_Info,
 	^QOI_Info,
+	^TGA_Info,
 }
 
 
@@ -168,6 +169,7 @@ Error :: union #shared_nil {
 
 General_Image_Error :: enum {
 	None = 0,
+	Unsupported_Option,
 	// File I/O
 	Unable_To_Read_File,
 	Unable_To_Write_File,
@@ -376,10 +378,15 @@ QOI_Info :: struct {
 	header: QOI_Header,
 }
 
+TGA_Data_Type :: enum u8  {
+	Uncompressed_RGB = 2,
+	Compressed_RBB   = 10,
+}
+
 TGA_Header :: struct #packed {
 	id_length:        u8,
 	color_map_type:   u8,
-	data_type_code:   u8,
+	data_type_code:   TGA_Data_Type,
 	color_map_origin: u16le,
 	color_map_length: u16le,
 	color_map_depth:  u8,
@@ -390,6 +397,21 @@ TGA_Header :: struct #packed {
 }
 #assert(size_of(TGA_Header) == 18)
 
+New_TGA_Signature :: "TRUEVISION-XFILE.\x00"
+
+TGA_Footer :: struct #packed {
+	extension_area_offset:      u32le,
+	developer_directory_offset: u32le,
+	signature:                  [18]u8 `fmt:"s"`, // Should match signature if New TGA.
+}
+#assert(size_of(TGA_Footer) == 26)
+
+TGA_Info :: struct {
+	header:   TGA_Header,
+	image_id: string,
+	footer:   Maybe(TGA_Footer),
+}
+
 // Function to help with image buffer calculations
 compute_buffer_size :: proc(width, height, channels, depth: int, extra_row_bytes := int(0)) -> (size: int) {
 	size = ((((channels * width * depth) + 7) >> 3) + extra_row_bytes) * height
diff --git a/core/image/tga/tga.odin b/core/image/tga/tga.odin
index 67a088eb5..d257d06ff 100644
--- a/core/image/tga/tga.odin
+++ b/core/image/tga/tga.odin
@@ -4,6 +4,7 @@
 
 	List of contributors:
 		Jeroen van Rijn: Initial implementation.
+		Benoit Jacquier: tga loader
 */
 
 
@@ -14,6 +15,12 @@ import "core:mem"
 import "core:image"
 import "core:bytes"
 import "core:os"
+import "core:compress"
+import "core:strings"
+import "core:fmt"
+_ :: fmt
+
+// TODO: alpha_premultiply support
 
 Error   :: image.Error
 Image   :: image.Image
@@ -57,7 +64,7 @@ save_to_memory  :: proc(output: ^bytes.Buffer, img: ^Image, options := Options{}
 	}
 
 	header := image.TGA_Header{
-		data_type_code   = 0x02, // Color, uncompressed.
+		data_type_code   = .Uncompressed_RGB,
 		dimensions       = {u16le(img.width), u16le(img.height)},
 		bits_per_pixel   = u8(img.depth * img.channels),
 		image_descriptor = 1 << 5, // Origin is top left.
@@ -98,4 +105,214 @@ save_to_file :: proc(output: string, img: ^Image, options := Options{}, allocato
 	return nil if write_ok else .Unable_To_Write_File
 }
 
-save :: proc{save_to_memory, save_to_file}
\ No newline at end of file
+save :: proc{save_to_memory, save_to_file}
+
+load_from_context :: proc(ctx: ^$C, options := Options{}, allocator := context.allocator) -> (img: ^Image, err: Error) {
+	context.allocator = allocator
+	options := options
+
+	if .alpha_premultiply in options {
+		return nil, .Unsupported_Option
+	}
+
+	if .info in options {
+		options |= {.return_metadata, .do_not_decompress_image}
+		options -= {.info}
+	}
+
+	if .return_header in options && .return_metadata in options {
+		options -= {.return_header}
+	}
+
+	// First check for a footer.
+	filesize := compress.input_size(ctx) or_return
+
+	footer: image.TGA_Footer
+	have_valid_footer := false
+
+	if filesize >= size_of(image.TGA_Header) + size_of(image.TGA_Footer) {
+		if f, f_err := compress.peek_data(ctx, image.TGA_Footer, filesize - i64(size_of(image.TGA_Footer))); f_err == .None {
+			if string(f.signature[:]) == image.New_TGA_Signature {
+				have_valid_footer = true
+				footer = f
+			}
+		}
+	}
+
+	header := image.read_data(ctx, image.TGA_Header) or_return
+	
+	// Header checks
+	rle_encoding := false 
+
+	switch header.data_type_code {
+		case .Compressed_RBB: rle_encoding = true
+		case .Uncompressed_RGB:
+		case: return nil, .Unsupported_Format 	
+	}
+
+	if header.bits_per_pixel != 24 && header.bits_per_pixel != 32 {
+		return nil, .Unsupported_Format
+	}
+
+	if header.image_descriptor & IMAGE_DESCRIPTOR_INTERLEAVING_MASK != 0 {
+		return nil, .Unsupported_Format
+	}
+
+	if int(header.dimensions[0]) * int(header.dimensions[1]) > image.MAX_DIMENSIONS {
+		return nil, .Image_Dimensions_Too_Large
+	}
+
+	if img == nil {
+		img = new(Image)
+	}
+
+	defer if err != nil {
+		destroy(img)
+	}
+
+	src_channels := int(header.bits_per_pixel) / 8
+	img.which = .TGA
+	img.channels = 4 if .alpha_add_if_missing  in options else src_channels
+	img.channels = 3 if .alpha_drop_if_present in options else img.channels
+
+	img.depth  = 8
+	img.width  = int(header.dimensions[0])
+	img.height = int(header.dimensions[1])
+
+	// Read Image ID if present
+	image_id := ""
+	if _id, e := compress.read_slice(ctx, int(header.id_length)); e != .None {
+		return nil, .Corrupt
+	} else {
+		if .return_metadata in options {
+			id := strings.trim_right_null(string(_id))
+			image_id = strings.clone(id)
+		}
+	}
+
+	if .return_metadata in options {
+		info := new(image.TGA_Info)
+		info.header   = header
+		info.image_id = image_id
+		if have_valid_footer {
+			info.footer = footer
+		}
+		img.metadata = info
+	}
+
+	if .do_not_decompress_image in options {
+		return img, nil
+	}
+
+	if !resize(&img.pixels.buf, img.channels * img.width * img.height) {
+		return img, .Unable_To_Allocate_Or_Resize
+	}
+
+	origin_is_topleft    := header.image_descriptor & IMAGE_DESCRIPTOR_TOPLEFT_MASK != 0
+	rle_repetition_count := 0
+	read_pixel           := true
+	is_packet_rle        := false
+
+	pixel: [4]u8
+
+	stride := img.width * img.channels
+	line   := 0 if origin_is_topleft else img.height - 1
+
+	for _ in 0..<img.height {
+		offset := line * stride
+		for _ in 0..<img.width {
+			// handle RLE decoding
+			if rle_encoding {
+				if rle_repetition_count == 0 {
+					rle_cmd, err := compress.read_u8(ctx)
+					if err != .None {
+						return img, .Corrupt
+					}
+					is_packet_rle = (rle_cmd >> 7) != 0
+					rle_repetition_count = 1 + int(rle_cmd & 0x7F)
+					read_pixel = true
+				} else if !is_packet_rle {
+					read_pixel = rle_repetition_count > 0
+				} else {
+					read_pixel = false
+				}
+			}
+			// Read pixel
+			if read_pixel {
+				src, src_err := compress.read_slice(ctx, src_channels)
+				if src_err != .None {
+					return img, .Corrupt
+				}
+
+				pixel[2] = src[0]
+				pixel[1] = src[1]
+				pixel[0] = src[2]
+
+				pixel[3] = src_channels == 4 ? src[3] : 255
+				if img.channels == 4 {
+					if src_channels == 4 {
+						img.pixels.buf[offset:][3] = src[3]
+					} else {
+						img.pixels.buf[offset:][3] = 255
+					}
+				}
+			}
+
+			// Write pixel
+			copy(img.pixels.buf[offset:], pixel[:img.channels])
+			offset += img.channels
+			rle_repetition_count -= 1
+		}
+		line += 1 if origin_is_topleft else -1
+	}
+	return img, nil
+}
+
+load_from_bytes :: proc(data: []byte, options := Options{}, allocator := context.allocator) -> (img: ^Image, err: Error) {
+	ctx := &compress.Context_Memory_Input{
+		input_data = data,
+	}
+
+	img, err = load_from_context(ctx, options, allocator)
+	return img, err
+}
+
+load_from_file :: proc(filename: string, options := Options{}, allocator := context.allocator) -> (img: ^Image, err: Error) {
+	context.allocator = allocator
+
+	data, ok := os.read_entire_file(filename)
+	defer delete(data)
+
+	if ok {
+		return load_from_bytes(data, options)
+	} else {
+		return nil, .Unable_To_Read_File
+	}
+}
+
+load :: proc{load_from_file, load_from_bytes, load_from_context}
+
+destroy :: proc(img: ^Image) {
+	if img == nil || img.width == 0 || img.height == 0 {
+		return
+	}
+
+	bytes.buffer_destroy(&img.pixels)
+	if v, ok := img.metadata.(^image.TGA_Info); ok {
+		delete(v.image_id)
+		free(v)
+	}
+
+	// Make destroy idempotent
+	img.width  = 0
+	img.height = 0
+	free(img)
+}
+
+IMAGE_DESCRIPTOR_INTERLEAVING_MASK :: (1<<6) | (1<<7)
+IMAGE_DESCRIPTOR_TOPLEFT_MASK :: 1<<5
+
+@(init, private)
+_register :: proc() {
+	image.register(.TGA, load_from_bytes, destroy)
+}
\ No newline at end of file