From 7199e74aa22e592a3b77bdd81f735edca5470596 Mon Sep 17 00:00:00 2001
From: Benji Dial <benji@benjidial.net>
Date: Sat, 20 Jan 2024 17:59:40 -0500
Subject: update

---
 libraries/daguerre/ppm.cpp | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 libraries/daguerre/ppm.cpp

(limited to 'libraries/daguerre/ppm.cpp')

diff --git a/libraries/daguerre/ppm.cpp b/libraries/daguerre/ppm.cpp
new file mode 100644
index 0000000..e909503
--- /dev/null
+++ b/libraries/daguerre/ppm.cpp
@@ -0,0 +1,52 @@
+#include <daguerre/image.hpp>
+#include <cctype>
+
+namespace daguerre {
+
+  static unsigned read_int(std::FILE *from) {
+    unsigned out = 0;
+    int ch;
+    do
+      ch = std::fgetc(from);
+    while (std::isspace(ch));
+    while (true) {
+      if (ch == EOF)
+        return out;
+      if (ch < '0' || ch > '9') {
+        std::ungetc(ch, from);
+        return out;
+      }
+      out = out * 10 + (ch - '0');
+      ch = std::fgetc(from);
+    }
+  }
+
+  bool try_load_ppm(std::FILE *from, image<color24> &into) {
+
+    if (std::fgetc(from) != 'P' || std::fgetc(from) != '6' ||
+        std::fgetc(from) != '\n')
+      return false;
+
+    unsigned width = read_int(from);
+    unsigned height = read_int(from);
+    unsigned max = read_int(from);
+    std::fgetc(from);//newline
+
+    if (max != 255)
+      return false;
+
+    into = image<color24>(width, height);
+    color24 *buffer = into.get_buffer();
+
+    for (unsigned y = 0; y < height; ++y)
+      for (unsigned x = 0; x < width; ++x) {
+        buffer[y * width + x].r = std::fgetc(from);
+        buffer[y * width + x].g = std::fgetc(from);
+        buffer[y * width + x].b = std::fgetc(from);
+      }
+
+    return true;
+
+  }
+
+}
-- 
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