1 files changed, 206 insertions, 0 deletions
diff --git a/src/image.cpp b/src/image.cpp
new file mode 100644
index 0000000..ab0b2f9
--- /dev/null
+++ b/src/image.cpp
@@ -0,0 +1,206 @@
+#include "image.hpp"
+
+#include "stb_image.h"
+
+#include <csetjmp>
+#include <format>
+#include <fud_c_file.hpp>
+#include <spdlog/spdlog.h>
+
+// Include jpeglib last
+#include <jpeglib.h>
+#include <turbojpeg.h>
+
+namespace bookmouse {
+
+class JpegFile {
+  public:
+    ~JpegFile();
+    void decompress(fud::CBinaryFile& inFile);
+
+  private:
+    jpeg_decompress_struct m_cinfo{};
+};
+
+JpegFile::~JpegFile()
+{
+    jpeg_destroy_decompress(&m_cinfo);
+}
+
+void JpegFile::decompress(fud::CBinaryFile& inFile)
+{
+    jpeg_create_decompress(&m_cinfo);
+    auto* file = inFile.file();
+    if (file == nullptr) {
+        // early return
+    }
+    jpeg_stdio_src(&m_cinfo, inFile.file());
+    auto result = jpeg_read_header(&m_cinfo, true);
+    if (result == JPEG_SUSPENDED) {
+        // early return
+    }
+}
+
+struct my_error_mgr {
+    struct jpeg_error_mgr pub; /* "public" fields */
+
+    jmp_buf setjmp_buffer; /* for return to caller */
+};
+
+typedef struct my_error_mgr* my_error_ptr;
+
+METHODDEF(void)
+my_error_exit(j_common_ptr cinfo) __attribute__((__noreturn__));
+
+METHODDEF(void)
+my_error_exit(j_common_ptr cinfo)
+{
+    /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
+    my_error_ptr myerr = (my_error_ptr)cinfo->err;
+
+    /* Always display the message. */
+    /* We could postpone this until after returning, if we chose. */
+    (*cinfo->err->output_message)(cinfo);
+
+    /* Return control to the setjmp point */
+    longjmp(myerr->setjmp_buffer, 1);
+}
+
+ImageResult JpegImage::output() const
+{
+    auto err = [](ImageError eid) { return ImageResult::error(eid); };
+    ImageOutput image{};
+
+    struct jpeg_decompress_struct cinfo;
+
+    struct my_error_mgr jerr;
+
+    fud::CBinaryFile infile{m_filename, fud::CFileMode::ReadOnly};
+    JSAMPARRAY buffer = nullptr;     /* Output row buffer */
+    J12SAMPARRAY buffer12 = nullptr; /* 12-bit output row buffer */
+    int col;
+    int row_stride; /* physical row width in output buffer */
+
+    /* In this example we want to open the input and output files before doing
+     * anything else, so that the setjmp() error recovery below can assume the
+     * files are open.
+     *
+     * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
+     * requires it in order to read/write binary files.
+     */
+
+    auto fileResult = infile.open();
+    using fud::FileResult;
+    if (fileResult == FileResult::Error) {
+        spdlog::error("can't open {}\n", m_filename.c_str());
+        return err(ImageError::FileError);
+    }
+
+    /* Step 1: allocate and initialize JPEG decompression object */
+
+    /* We set up the normal JPEG error routines, then override error_exit. */
+    cinfo.err = jpeg_std_error(&jerr.pub);
+    jerr.pub.error_exit = my_error_exit;
+    /* Establish the setjmp return context for my_error_exit to use. */
+    if (setjmp(jerr.setjmp_buffer)) {
+        /* If we get here, the JPEG code has signaled an error.
+         * We need to clean up the JPEG object, close the input file, and return.
+         */
+        jpeg_destroy_decompress(&cinfo);
+        return err(ImageError::JpegError);
+    }
+    /* Now we can initialize the JPEG decompression object. */
+    jpeg_create_decompress(&cinfo);
+
+    /* Step 2: specify data source (eg, a file) */
+    jpeg_stdio_src(&cinfo, infile.file());
+
+    /* Step 3: read file parameters with jpeg_read_header() */
+
+    (void)jpeg_read_header(&cinfo, TRUE);
+    /* We can ignore the return value from jpeg_read_header since
+     *   (a) suspension is not possible with the stdio data source, and
+     *   (b) we passed TRUE to reject a tables-only JPEG file as an error.
+     * See libjpeg.txt for more info.
+     */
+
+    /* Step 4: Start decompressor */
+
+    jpeg_start_decompress(&cinfo);
+    /* We can ignore the return value since suspension is not possible
+     * with the stdio data source.
+     */
+
+    /* We may need to do some setup of our own at this point before reading
+     * the data.  After jpeg_start_decompress() we have the correct scaled
+     * output image dimensions available, as well as the output colormap
+     * if we asked for color quantization.
+     * In this example, we need to make an output work buffer of the right size.
+     */
+    /* Samples per row in output buffer */
+    if (cinfo.output_components < 0) {
+        // handle it
+        return err(ImageError::JpegError);
+    }
+    row_stride = static_cast<int>(cinfo.output_width) * cinfo.output_components;
+    /* Make a one-row-high sample array that will go away when done with image */
+    if (cinfo.data_precision == 12) {
+        buffer12 = (J12SAMPARRAY)(*cinfo.mem->alloc_sarray)(
+            (j_common_ptr)&cinfo,
+            JPOOL_IMAGE,
+            static_cast<JDIMENSION>(row_stride),
+            1);
+    } else {
+        buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr)&cinfo, JPOOL_IMAGE, static_cast<JDIMENSION>(row_stride), 1);
+    }
+
+    /* Step 5: while (scan lines remain to be read) */
+    /*           jpeg_read_scanlines(...); */
+
+    /* Here we use the library's state variable cinfo.output_scanline as the
+     * loop counter, so that we don't have to keep track ourselves.
+     */
+    if (cinfo.data_precision == 12) {
+        while (cinfo.output_scanline < cinfo.output_height) {
+            /* jpeg12_read_scanlines expects an array of pointers to scanlines.
+             * Here the array is only one element long, but you could ask for
+             * more than one scanline at a time if that's more convenient.
+             */
+            (void)jpeg12_read_scanlines(&cinfo, buffer12, 1);
+            /* Swap MSB and LSB in each sample */
+            for (col = 0; col < row_stride; col++) {
+                buffer12[0][col] =                                           // break
+                    static_cast<J12SAMPLE>((buffer12[0][col] & 0xFF) << 8) | // break
+                    static_cast<J12SAMPLE>((buffer12[0][col] >> 8) & 0xFF);
+            }
+        }
+    } else {
+        while (cinfo.output_scanline < cinfo.output_height) {
+            /* jpeg_read_scanlines expects an array of pointers to scanlines.
+             * Here the array is only one element long, but you could ask for
+             * more than one scanline at a time if that's more convenient.
+             */
+            (void)jpeg_read_scanlines(&cinfo, buffer, 1);
+        }
+    }
+
+    /* Step 6: Finish decompression */
+
+    (void)jpeg_finish_decompress(&cinfo);
+    /* We can ignore the return value since suspension is not possible
+     * with the stdio data source.
+     */
+
+    /* Step 7: Release JPEG decompression object */
+
+    /* This is an important step since it will release a good deal of memory. */
+
+    /* At this point you may want to check to see whether any corrupt-data
+     * warnings occurred (test whether jerr.pub.num_warnings is nonzero).
+     */
+
+    /* And we're done! */
+    return ImageResult::okay(image);
+}
+
+} // namespace bookmouse