tune PDF raster resolution per native backend

1 files changed, 21 insertions, 4 deletions

diff --git a/src/pdf_bridge.c b/src/pdf_bridge.c
index a26fea55..320919b1 100644
--- a/src/pdf_bridge.c
+++ b/src/pdf_bridge.c
@@ -234,17 +234,24 @@ int
 pardes_pdf_render(
     pardes_pdf_document *document,
     int page_number,
+    int dpi,
+    int minimum_width,
+    int minimum_height,
     int max_dimension,
     pardes_pdf_pixmap *out)
 {
     return pardes_pdf_render_with_highlights(
-        document, page_number, max_dimension, NULL, 0, out);
+        document, page_number, dpi, minimum_width, minimum_height,
+        max_dimension, NULL, 0, out);
 }
 
 int
 pardes_pdf_render_with_highlights(
     pardes_pdf_document *document,
     int page_number,
+    int dpi,
+    int minimum_width,
+    int minimum_height,
     int max_dimension,
     const pardes_pdf_highlight *highlights,
     size_t highlight_count,
@@ -256,12 +263,15 @@ pardes_pdf_render_with_highlights(
     fz_path *path = NULL;
     fz_matrix ctm;
     fz_rect bounds;
+    float page_width;
+    float page_height;
     float longest;
-    float scale = 2.0f; /* 144 dpi; PDF user space is 72 dpi. */
+    float scale;
     size_t i;
 
     if (document == NULL || out == NULL || page_number < 0 ||
-        page_number >= document->page_count || max_dimension < 1 ||
+        page_number >= document->page_count || dpi < 1 ||
+        minimum_width < 0 || minimum_height < 0 || max_dimension < 1 ||
         (highlight_count != 0 && highlights == NULL) ||
         highlight_count > PARDES_PDF_MAX_RESULT_QUADS)
         return PARDES_PDF_ERROR;
@@ -275,9 +285,16 @@ pardes_pdf_render_with_highlights(
     {
         pardes_pdf_cache_page(document, page_number, 0);
         bounds = document->cached_bounds;
-        longest = fmaxf(bounds.x1 - bounds.x0, bounds.y1 - bounds.y0);
+        page_width = bounds.x1 - bounds.x0;
+        page_height = bounds.y1 - bounds.y0;
+        longest = fmaxf(page_width, page_height);
         if (!(longest > 0.0f))
             fz_throw(ctx, FZ_ERROR_FORMAT, "PDF page has empty bounds");
+        scale = (float)dpi / 72.0f;
+        if (minimum_width > 0)
+            scale = fmaxf(scale, (float)minimum_width / page_width);
+        if (minimum_height > 0)
+            scale = fmaxf(scale, (float)minimum_height / page_height);
         if (longest * scale > (float)max_dimension)
             scale = (float)max_dimension / longest;
         /*