Skip to content

Commit

Permalink
Merge pull request #2 from VishalRamki/v2.0
Browse files Browse the repository at this point in the history 
Added Support for P2/P5 Formats. Fixed Byte Misalignment, parse issues
  • Loading branch information
@VishalRamki
VishalRamki committed Mar 28, 2021
2 parents 0f229e4 + eaa7504 commit f64bf87
Show file tree
Hide file tree
Showing 2 changed files with 68 additions and 24 deletions.
7 changes: 7 additions & 0 deletions README.md
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,8 +16,15 @@ ppmviewer.exe "filename.ppm"

A window will pop up that matches the size of the input image.


## Change Log

### v1.2 => Road To v2.0

- Changes the way ASCII values are parsed. Previous it would insert random `0`s which would cause images to be misaligned. It now correctly filters out `Whitespace`
- Added Support for `P2` PPM File Format - Which is the Portable GrayMap. Also supports the `P5` format which is the binary version.
- Fixed issue where byte position weren't being correctly calculated. This resulted in images being misaligned by a pixel.

### v1.1 => Road to v2.0

- Ensures Comments are parsed out of the ASCII and Binary versions. i.e they are not processed and stripped before algorithm runs.
Expand Down
85 changes: 61 additions & 24 deletions src/main.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -53,14 +53,16 @@ struct PpmValue {
r: i32,
g: i32,
b: i32,
a: f32,
}

impl PpmValue {
fn new(red: i32, green: i32, blue: i32) -> Self {
fn new(red: i32, green: i32, blue: i32, alpha: f32) -> Self {
PpmValue {
r: red,
g: green,
b: blue,
a: alpha,
}
}
}
Expand All @@ -69,8 +71,12 @@ impl PpmValue {
/// Determines the format type of file based on the the first two bytes
/// of the Magic Number
enum PpmType {
/// P2 is the Grayscale Data in ASCII
P2,
/// P3 is the RGB Image data in ASCII
P3,
/// P5 is the Grayscale Data in Binary Format
P5,
/// P6 is the RGB Image Data in Binary Format
P6,
/// This is not a valid PPM/PGM/PBM File Format
Expand All @@ -91,18 +97,17 @@ impl PPM {

/// Reads the ASCII file. Right now we just return the values. This is done because we've already built the header data.
/// However, we have to read over the header, and parse data for now. @TODO: Fix this.
fn read_ppm_ascii_file(path: &str) -> Vec<PpmValue> {
fn read_ppm_ascii_file(path: &str, ppm_type: PpmType) -> Vec<PpmValue> {
let file = File::open(path).unwrap();
let mut dat : PPM = PPM::new();
dat.ppm_type = ppm_type;
let reader = BufReader::new(file);

let mut skip_first_line : bool = false;

for line in reader.lines() {
//println!("{}", line?);
let va = line.unwrap_or_default();
// @TODO This is because I am assuming all PPM files is going to be
// in the P3 format.
// we just skip over this line since we already have the ppm type
if !skip_first_line {
skip_first_line = true;
continue
Expand All @@ -116,6 +121,7 @@ fn read_ppm_ascii_file(path: &str) -> Vec<PpmValue> {
if dat.width == 0 && dat.height == 0 {
let bar : Vec<i32> = va.split(' ').map(|x| x.parse::<i32>().unwrap()).collect();
dat.width = bar[0];

dat.height = bar[1];
//println!("This is width & Height: {:?}", bar);
continue
Expand All @@ -131,10 +137,18 @@ fn read_ppm_ascii_file(path: &str) -> Vec<PpmValue> {
} else {
va.clone().find('#').unwrap_or_default()
};
let x : Vec<i32> = (&va[0..offset]).split(' ').map(|x| x.parse::<i32>().unwrap_or_default()).collect();
dat.values.push(PpmValue::new(x[0], x[1], x[2]));

let x : Vec<i32> = (&va[0..offset]).split_whitespace().map(|x| x.parse::<i32>().unwrap()).collect();
if dat.ppm_type == PpmType::P3 {
dat.values.push(PpmValue::new(x[0], x[1], x[2], 1.0));
}
else if dat.ppm_type == PpmType::P2 {
for val in x {
dat.values.push(PpmValue::new(((val as f32/dat.max_value as f32) * 255.0) as i32, ((val as f32/dat.max_value as f32) * 255.0) as i32, ((val as f32/dat.max_value as f32) * 255.0) as i32, 1.0));
//println!("{:?} / {:?} = {:?}", val as f32, dat.max_value as f32, ((val as f32/dat.max_value as f32) * 255.0) as i32);
}
}
}

dat.values
}

Expand All @@ -150,9 +164,15 @@ fn read_ppm_header(path: &str) -> (usize, PPM) {

f.read_exact(&mut magic_number).unwrap();
let ppm_type = match magic_number {
[80, 50] => {
PpmType::P2
},
[80, 51] => {
PpmType::P3
},
[80, 53] => {
PpmType::P5
},
[80, 54] => {
PpmType::P6
},
Expand All @@ -165,8 +185,8 @@ fn read_ppm_header(path: &str) -> (usize, PPM) {
// if we have found an ASCII ppm file (p3) then we pass this data onto
let mut byte_for = [0; 1]; // important note: 0x32 is the whitespace code.
while let Ok(n) = f.read(&mut byte_for) {
if header.width != 0 && header.height != 0 && header.max_value != 0
{
if header.width != 0 && header.height != 0 && header.max_value != 0 {
byte_position += 1;
break;
}
if n != 0 {
Expand All @@ -176,6 +196,7 @@ fn read_ppm_header(path: &str) -> (usize, PPM) {
// ensure we don't double read over an actual piece of information
if byte_for != [10] && byte_for != [32] && byte_for != [35] && byte_for != [13] {
number_byte.push(byte_for[0]);
byte_position += 1;
}
// read bytes until whitespace or \n
while let Ok(n) = f.read(&mut byte_for) {
Expand All @@ -200,7 +221,7 @@ fn read_ppm_header(path: &str) -> (usize, PPM) {
while let Ok(z) = f.read(&mut byte_for) {
if z!= 0 {
byte_position += 1;
if byte_for == [35] || byte_for == [13] {
if byte_for == [35] || byte_for == [13] || byte_for == [10]{
break;
}
}
Expand Down Expand Up @@ -243,17 +264,28 @@ fn read_ppm_header(path: &str) -> (usize, PPM) {
(byte_position, header)
}

fn read_ppm_binary_image_data(path: &str, ppm_type: PpmType, start_position: usize) -> Vec<PpmValue> {
fn read_ppm_binary_image_data(path: &str, ppm_object: PPM, start_position: usize) -> Vec<PpmValue> {
let mut f = File::open(path).unwrap();
// move the cursor 42 bytes from the start of the file
f.seek(SeekFrom::Start(start_position as u64)).unwrap();
f.seek(SeekFrom::Start((start_position) as u64)).unwrap();
let mut img_data = Vec::<PpmValue>::new();

if ppm_type == PpmType::P6 {
if ppm_object.ppm_type == PpmType::P6 {
let mut byte_for = [0; 3]; // important note: 0x32 is the whitespace code.
while let Ok(n) = f.read(&mut byte_for) {
if n != 0 {
img_data.push(PpmValue::new(i32::from_be_bytes([0,0,0,byte_for[0]]),i32::from_be_bytes([0,0,0,byte_for[1]]), i32::from_be_bytes([0,0,0,byte_for[2]])));
img_data.push(PpmValue::new(i32::from_be_bytes([0,0,0,byte_for[0]]),i32::from_be_bytes([0,0,0,byte_for[1]]), i32::from_be_bytes([0,0,0,byte_for[2]]), 1.0));
}
else {
break;
}
}
} else if ppm_object.ppm_type == PpmType::P5 {
let mut byte_for = [0; 1]; // important note: 0x32 is the whitespace code.
while let Ok(n) = f.read(&mut byte_for) {
if n != 0 {
let gs_data = i32::from_be_bytes([0,0,0,byte_for[0]]);
img_data.push(PpmValue::new(((gs_data as f32 / ppm_object.max_value as f32) * 255.0) as i32,((gs_data as f32 / ppm_object.max_value as f32) * 255.0) as i32,((gs_data as f32 / ppm_object.max_value as f32) * 255.0) as i32, 1.0));
}
else {
break;
Expand Down Expand Up @@ -281,11 +313,12 @@ fn main() -> Result<(), Error> {
}
let mut world = World::new();
let (byte_position, mut header) : (usize, PPM) = read_ppm_header(filename);
if header.ppm_type == PpmType::P3 {
header.values = read_ppm_ascii_file(filename);
if header.ppm_type == PpmType::P2 || header.ppm_type == PpmType::P3 {
header.values = read_ppm_ascii_file(filename, header.clone().ppm_type);
}
else if header.ppm_type == PpmType::P6 {
header.values = read_ppm_binary_image_data(filename, header.clone().ppm_type, byte_position);
else if header.ppm_type == PpmType::P6 || header.ppm_type == PpmType::P5 {
// there is an issue where byte were misaligned.
header.values = read_ppm_binary_image_data(filename, header.clone(), byte_position);
}
world.frame = Some(header);

Expand Down Expand Up @@ -374,11 +407,15 @@ impl World {
if self.single_draw && self.has_been_drawn {
return
}
for (i, pixel) in frame.chunks_exact_mut(4).enumerate() {
let frame_instance = self.frame.as_ref().unwrap();
let rgba = [frame_instance.values[i].r as u8, frame_instance.values[i].g as u8, frame_instance.values[i].b as u8, 0xff];
pixel.copy_from_slice(&rgba);
}
if self.frame.as_ref().unwrap().ppm_type == PpmType::P3 || self.frame.as_ref().unwrap().ppm_type == PpmType::P6 || self.frame.as_ref().unwrap().ppm_type == PpmType::P5 ||
self.frame.as_ref().unwrap().ppm_type == PpmType::P2 {
for (i, pixel) in frame.chunks_exact_mut(4).enumerate() {
let frame_instance = self.frame.as_ref().unwrap();
let rgba = [frame_instance.values[i].r as u8, frame_instance.values[i].g as u8, frame_instance.values[i].b as u8, 0xff];
pixel.copy_from_slice(&rgba);
}
}

if self.single_draw && !self.has_been_drawn {
self.has_been_drawn = true;
}
Expand Down

0 comments on commit f64bf87

Please sign in to comment.