From bf92c9b59c0bcc1d4a2ac1761dfd3fd913987987 Mon Sep 17 00:00:00 2001
From: Jeff Muizelaar <jrmuizel@gmail.com>
Date: Sat, 13 Jan 2024 14:10:23 -0500
Subject: [PATCH] Fix text matrix computation
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Previously we were doing:

 Trm = CTM × Tm × Tsm

instead of:

 Trm = Tsm × Tm × CTM
---
 src/lib.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index a77fe2d..2db60c2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1190,14 +1190,15 @@ fn show_text(gs: &mut GraphicsState, s: &[u8],
     output.begin_word()?;
 
     for (c, length) in font.char_codes(s) {
+        // 5.3.3 Text Space Details
         let tsm = Transform2D::row_major(ts.horizontal_scaling,
                                                  0.,
                                                  0.,
                                                  1.0,
                                                  0.,
                                                  ts.rise);
-        let trm = ts.tm.pre_transform(&gs.ctm);
-        let trm = trm.post_transform(&tsm);
+        // Trm = Tsm × Tm × CTM
+        let trm = tsm.post_transform(&ts.tm.post_transform(&gs.ctm));
         //dlog!("ctm: {:?} tm {:?}", gs.ctm, tm);
         //dlog!("current pos: {:?}", position);
         // 5.9 Extraction of Text Content