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Convert PDF page-space points to bitmap pixel coordinates

Source: R/render.R
pdf_bitmap_from_page.Rd

Inverse of pdf_bitmap_to_page(). Translates PDF user-space points to pixel positions on a pdfium_bitmap (returned by pdf_render_page()). Wraps FPDF_PageToDevice with the render-geometry that produced the bitmap pre-populated from the bitmap's attributes.

Usage

pdf_bitmap_from_page(bitmap, x, y)

Arguments

bitmap

A pdfium_bitmap from pdf_render_page().

x, y

Numeric vectors of PDF user-space coordinates. Recycled to a common length.

Value

A two-column tibble with integer columns x and y in bitmap pixel coordinates (origin at the bitmap's top-left).

See also

pdf_bitmap_to_page() for the inverse, pdf_page_to_device() for the underlying primitive.

Examples

fixture <- system.file("extdata", "fixtures", "shapes.pdf",
  package = "pdfium"
)
if (nzchar(fixture)) {
  doc <- pdf_doc_open(fixture)
  bmp <- pdf_render_page(doc, dpi = 72)
  # Map PDF page-space points (bottom-left origin) to bitmap pixels.
  pdf_bitmap_from_page(bmp, x = c(0, 72), y = c(0, 72))
  pdf_doc_close(doc)
}