Add support for export Softpal PGD Differential Image File (.pgd)

src/scripts/softpal/img/pgd/pgd3.rs

@@ -0,0 +1,198 @@
+use super::base::*;
+use crate::ext::io::*;
+use crate::scripts::base::*;
+use crate::types::*;
+use crate::utils::img::*;
+use crate::utils::struct_pack::*;
+use anyhow::Result;
+use std::io::{Read, Seek};
+
+#[derive(Debug)]
+pub struct Pgd3Builder {}
+
+impl Pgd3Builder {
+    pub fn new() -> Self {
+        Self {}
+    }
+}
+
+impl ScriptBuilder for Pgd3Builder {
+    fn default_encoding(&self) -> Encoding {
+        Encoding::Cp932
+    }
+
+    fn build_script(
+        &self,
+        buf: Vec<u8>,
+        filename: &str,
+        encoding: Encoding,
+        _archive_encoding: Encoding,
+        config: &ExtraConfig,
+        archive: Option<&Box<dyn Script>>,
+    ) -> Result<Box<dyn Script>> {
+        Ok(Box::new(Pgd3::new(
+            MemReader::new(buf),
+            filename,
+            encoding,
+            config,
+            archive,
+        )?))
+    }
+
+    fn extensions(&self) -> &'static [&'static str] {
+        &["pgd"]
+    }
+
+    fn script_type(&self) -> &'static ScriptType {
+        &ScriptType::SoftpalPgd3
+    }
+
+    fn is_image(&self) -> bool {
+        true
+    }
+
+    fn is_this_format(&self, _filename: &str, buf: &[u8], buf_len: usize) -> Option<u8> {
+        if buf_len >= 4 && (buf.starts_with(b"PGD3") || buf.starts_with(b"PGD2")) {
+            return Some(20);
+        }
+        None
+    }
+}
+
+#[derive(Debug)]
+pub struct Pgd3 {
+    header: PgdDiffHeader,
+    base_header: PgdGeHeader,
+    base: ImageData,
+    diff: ImageData,
+}
+
+impl Pgd3 {
+    pub fn new<R: Read + Seek>(
+        mut reader: R,
+        filename: &str,
+        encoding: Encoding,
+        _config: &ExtraConfig,
+        archive: Option<&Box<dyn Script>>,
+    ) -> Result<Self> {
+        let mut sig = [0u8; 4];
+        reader.read_exact(&mut sig)?;
+        if &sig != b"PGD3" && &sig != b"PGD2" {
+            return Err(anyhow::anyhow!("Not a valid PGD3/PGD2 file"));
+        }
+        let header = PgdDiffHeader::unpack(&mut reader, false, encoding)?;
+        let diff = PgdReader::with_diff_header(reader, &header)?.unpack_overlay()?;
+        let base: Vec<u8> = if let Some(archive) = archive {
+            let mut file = archive.open_file_by_name(&header.base_name, true)?;
+            file.data()?
+        } else {
+            let path = {
+                let mut pb = std::path::PathBuf::from(filename);
+                pb.set_file_name(&header.base_name);
+                pb
+            };
+            crate::utils::files::read_file(&path).map_err(|e| {
+                anyhow::anyhow!("Failed to read base image file '{}': {}", path.display(), e)
+            })?
+        };
+        let mut reader = MemReader::new(base);
+        reader.read_exact(&mut sig)?;
+        if &sig != b"GE \0" {
+            return Err(anyhow::anyhow!(
+                "Base image file '{}' is not a valid GE file",
+                header.base_name
+            ));
+        }
+        let base_header = PgdGeHeader::unpack(&mut reader, false, encoding)?;
+        let base = PgdReader::with_ge_header(reader, &base_header)?.unpack_ge()?;
+        Ok(Self {
+            header,
+            base_header,
+            base,
+            diff,
+        })
+    }
+}
+
+impl Script for Pgd3 {
+    fn default_output_script_type(&self) -> OutputScriptType {
+        OutputScriptType::Json
+    }
+
+    fn default_format_type(&self) -> FormatOptions {
+        FormatOptions::None
+    }
+
+    fn is_image(&self) -> bool {
+        true
+    }
+
+    fn export_image(&self) -> Result<ImageData> {
+        let mut base = if self.base_header.is_base_file() {
+            self.base.clone()
+        } else {
+            draw_on_canvas(
+                self.base.clone(),
+                self.base_header.canvas_width,
+                self.base_header.canvas_height,
+                self.base_header.offset_x,
+                self.base_header.offset_y,
+            )?
+        };
+        draw_on_img(
+            &mut base,
+            &self.diff,
+            self.header.offset_x as u32,
+            self.header.offset_y as u32,
+        )?;
+        Ok(base)
+    }
+}
+
+fn draw_on_img(base: &mut ImageData, diff: &ImageData, left: u32, top: u32) -> Result<()> {
+    if base.color_type != diff.color_type {
+        return Err(anyhow::anyhow!(
+            "Color types do not match: {:?} vs {:?}",
+            base.color_type,
+            diff.color_type
+        ));
+    }
+    let bpp = base.color_type.bpp(1) as usize;
+    let base_stride = base.width as usize * bpp;
+    let diff_stride = diff.width as usize * bpp;
+
+    for y in 0..diff.height {
+        let base_y = top + y;
+        if base_y >= base.height {
+            continue; // Skip if the base image is not tall enough
+        }
+
+        for x in 0..diff.width {
+            let base_x = left + x;
+            if base_x >= base.width {
+                continue; // Skip if the base image is not wide enough
+            }
+
+            let base_index = (base_y as usize * base_stride) + (base_x as usize * bpp);
+            let diff_index = (y as usize * diff_stride) + (x as usize * bpp);
+
+            let diff_pixel = &diff.data[diff_index..diff_index + bpp];
+            let base_pixel_orig = base.data[base_index..base_index + bpp].to_vec();
+            let mut b = base_pixel_orig[0];
+            let mut g = base_pixel_orig[1];
+            let mut r = base_pixel_orig[2];
+            b ^= diff_pixel[0];
+            g ^= diff_pixel[1];
+            r ^= diff_pixel[2];
+            base.data[base_index] = b;
+            base.data[base_index + 1] = g;
+            base.data[base_index + 2] = r;
+            if bpp == 4 {
+                let mut a = base_pixel_orig[3];
+                a ^= diff_pixel[3];
+                base.data[base_index + 3] = a;
+            }
+        }
+    }
+    Ok(())
+}