zoom_book.c

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#ifdef __has_include
#if __has_include("book_paged.h")
#define ZOOM_HAVE_BOOK
#endif
#endif
 
#ifdef ZOOM_HAVE_BOOK
 
#include "zoom_book.h"
 
#include <stdint.h>
 
#include "book.h"
#include "book_paged.h"
#include "ra8_check.h"
#include "ra8_err.h"
#include "zoom.h"

static const char* const s_tag = "zoom_book";
 
ra8_err_t zoom_book_src_init(zoom_book_src_t* bs, const book_src_t* src, uint32_t img_idx)
{
  RA8_CHECK_NULL_PTR(bs, s_tag, "binding must not be nullptr");
  RA8_CHECK_NULL_PTR(src, s_tag, "book source must not be nullptr");
  book_image_t img = {};
  RA8_RETURN_ON_ERROR(book_src_image(src, img_idx, &img), s_tag, "image descriptor read");
  if (img.format != (uint8_t)k_book_image_gray4) {
    ra8_log_error(s_tag, "vector images are not magnifiable by the raster viewer");
    return k_ra8_err_not_supported;
  }
  /* Decision: a raster with no extent cannot be magnified (2 conditions). */
  if ((img.width == 0U) || (img.height == 0U)) {
    ra8_log_error(s_tag, "image descriptor has a zero extent");
    return k_ra8_err_invalid_arg;
  }
  bs->src = src;
  bs->img = img;
  return k_ra8_ok;
}
 
ra8_err_t zoom_book_src_bind(zoom_book_src_t* bs, zoom_source_t* out)
{
  RA8_CHECK_NULL_PTR(bs, s_tag, "binding must not be nullptr");
  RA8_CHECK_NULL_PTR(out, s_tag, "source out must not be nullptr");
  RA8_CHECK_NULL_PTR(bs->src, s_tag, "binding was never initialised");
  return zoom_source_init(out,
                          zoom_book_read,
                          bs,
                          (uint32_t)bs->img.width,
                          (uint32_t)bs->img.height);
}
 
ra8_err_t zoom_book_read(void*    ctx,
                         uint32_t x,
                         uint32_t y,
                         uint32_t w,
                         uint32_t h,
                         uint8_t* out,
                         uint32_t out_stride)
{
  RA8_CHECK_NULL_PTR(ctx, s_tag, "read ctx must not be nullptr");
  RA8_CHECK_NULL_PTR(out, s_tag, "read destination must not be nullptr");
  const zoom_book_src_t* bs = (const zoom_book_src_t*)ctx;
  RA8_CHECK_NULL_PTR(bs->src, s_tag, "binding was never initialised");
  return book_src_image_rect(bs->src, &bs->img, x, y, w, h, out, out_stride);
}
 
#endif /* ZOOM_HAVE_BOOK */