From dac0bb3ca1c725ef968a07bb89fa96ebdc7fb0b9 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Sun, 28 Jun 2009 18:18:01 +0100
Subject: [PATCH] Faster, by more in-bulk processing of incoming pixels

---
 pctb/convert.h  |  1 +
 pctb/pages.c    | 24 +++++++++---------------
 pctb/rgbimage.c | 11 +++++++++++
 3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/pctb/convert.h b/pctb/convert.h
index 0abdf93..80979ec 100644
--- a/pctb/convert.h
+++ b/pctb/convert.h
@@ -54,6 +54,7 @@ typedef struct RgbImage {
 void identify_rgbimage(const RgbImage *base, Rect portion,
 		       char result[MAXIMGIDENT], const char *what);
 RgbImage *alloc_rgb_image(int w, int h);
+void fwrite_ppmraw(FILE *f, const RgbImage *ri);
 
 #define RI_PIXEL(ri,x,y) ((ri)->data + ((y)*(ri)->w + (x)) * 3)
 
diff --git a/pctb/pages.c b/pctb/pages.c
index a0a52b4..d298ac4 100644
--- a/pctb/pages.c
+++ b/pctb/pages.c
@@ -497,24 +497,18 @@ static void set_focus_commodity(void) {
 static CanonImage *convert_page(Snapshot *sn, RgbImage *ri) {
   CanonImage *im;
 
-  fprintf(screenshot_file,
-	  "P6\n"
-	  "%d %d\n"
-	  "255\n", sn->w, sn->h);
+  fwrite_ppmraw(screenshot_file, sn);
+  if (ri) memcpy(ri->data, sn->data, ri->h * ri->w * 3);
 
+  unsigned char *pixel= sn->data;
   CANONICALISE_IMAGE(im, sn->w, sn->h, {
-    int i;
-    rgb= 0;
-    for (i=0; i<3; i++) {
-      rgb <<= 8;
-      unsigned long sample= RI_PIXEL(sn,x,y)[i];
-      rgb |= sample;
-      fputc(sample, screenshot_file);
-    }
-    if (ri)
-      CANONIMG_ALSO_STORERGB(ri);
+    rgb=
+      (pixel[0] << 16) |
+      (pixel[1] <<  8) |
+      (pixel[2]      );
+    pixel += 3;
   });
-
+    
   sysassert(!ferror(screenshot_file));
   sysassert(!fflush(screenshot_file));
 
diff --git a/pctb/rgbimage.c b/pctb/rgbimage.c
index c4fd11d..720e5dc 100644
--- a/pctb/rgbimage.c
+++ b/pctb/rgbimage.c
@@ -115,6 +115,17 @@ static int identify(const RgbImage *base, Rect portion,
          identify1(base,portion,result,what, "local");
 }
 
+void fwrite_ppmraw(FILE *f, const RgbImage *ri) {
+  fprintf(f,
+	  "P6\n"
+	  "%d %d\n"
+	  "255\n", ri->w, ri->h);
+  int count= ri->w * ri->h * 3;
+  sysassert( fwrite(ri->data, 1, count, f) == count );
+  sysassert(!ferror(f));
+  sysassert(!fflush(f));
+}
+
 static void fwrite_ppm(FILE *f, const RgbImage *base, Rect portion) {
   int x,y,i;
   fprintf(f,"P3\n%d %d\n255\n", RECT_W(portion), RECT_H(portion));
-- 
2.30.2