Beispielprogramme 28.1.2019

20190128/gen-pbm-3.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main (void)
+{
+  int width = 16;
+  int height = 16;
+  FILE *f = fopen ("test.pbm", "w");
+  fprintf (f, "P4\n%d %d\n", width, height);
+
+  uint16_t data = 1;
+  for (int i = 0; i < 16; i++)
+    {
+      uint8_t right_half = data & 0x00ff;
+      uint8_t left_half = (data & 0xff00) >> 8;
+      fprintf (f, "%c%c", left_half, right_half);
+      data <<= 1;
+    }
+
+  return 0;
+}

20190128/show-pbm-1.c

+#include <stdio.h>
+
+int main (void)
+{
+  FILE *f = fopen ("test.pbm", "r");
+  char id[42];
+  int width, height;
+  fscanf (f, "%s", id);  // should be "P4"
+  printf ("%s\n", id);
+  fscanf (f, "%d", &width);
+  fscanf (f, "%d", &height);
+  printf ("%d %d\n", width, height);
+  return 0;
+}

20190128/show-pbm-2.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main (void)
+{
+  FILE *f = fopen ("test.pbm", "r");
+  char id[42];
+  int width, height;
+  fscanf (f, "%s", id);  // should be "P4"
+  fscanf (f, "%d", &width);
+  fscanf (f, "%d", &height);
+
+  for (int y = 0; y < height; y++)
+    {
+      for (int x = 0; x < (width + 7) / 8; x++)
+        {
+          uint8_t data;
+          fscanf (f, "%c", &data);
+          for (int i = 0; i < 7; i++)
+            if (data & (1 << i))
+              printf ("*");
+            else
+              printf (" ");
+        }
+      printf ("\n");
+    }
+
+  return 0;
+}

20190128/show-pbm-3.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main (void)
+{
+  FILE *f = fopen ("test.pbm", "r");
+  char id[42];
+  int width, height;
+  fscanf (f, "%s", id);  // should be "P4"
+  fscanf (f, "%d", &width);
+  fscanf (f, "%d", &height);
+  uint8_t dummy;
+  fscanf (f, "%c", &dummy);
+
+  for (int y = 0; y < height; y++)
+    {
+      for (int x = 0; x < (width + 7) / 8; x++)
+        {
+          uint8_t data;
+          fscanf (f, "%c", &data);
+          for (int i = 0; i < 7; i++)
+            if (data & (1 << i))
+              printf ("*");
+            else
+              printf (" ");
+        }
+      printf ("\n");
+    }
+
+  return 0;
+}

20190128/show-pbm-4.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main (void)
+{
+  FILE *f = fopen ("test.pbm", "r");
+  char id[42];
+  int width, height;
+  fscanf (f, "%s", id);  // should be "P4"
+  fscanf (f, "%d", &width);
+  fscanf (f, "%d", &height);
+  uint8_t dummy;
+  fscanf (f, "%c", &dummy);
+
+  for (int y = 0; y < height; y++)
+    {
+      for (int x = 0; x < (width + 7) / 8; x++)
+        {
+          uint8_t data;
+          fscanf (f, "%c", &data);
+          for (int i = 7; i >= 0; i--)
+            if (data & (1 << i))
+              printf ("*");
+            else
+              printf (" ");
+        }
+      printf ("\n");
+    }
+
+  return 0;
+}

20190128/show-pbm-5.c

+#include <stdio.h>
+#include <stdint.h>
+
+int main (void)
+{
+  FILE *f = fopen ("molpy-right.pbm", "r");
+  char id[42];
+  int width, height;
+  fscanf (f, "%s", id);  // should be "P4"
+  fscanf (f, "%d", &width);
+  fscanf (f, "%d", &height);
+  uint8_t dummy;
+  fscanf (f, "%c", &dummy);
+
+  for (int y = 0; y < height; y++)
+    {
+      for (int x = 0; x < (width + 7) / 8; x++)
+        {
+          uint8_t data;
+          fscanf (f, "%c", &data);
+          for (int i = 7; i >= 0; i--)
+            if (data & (1 << i))
+              printf ("*");
+            else
+              printf (" ");
+        }
+      printf ("\n");
+    }
+
+  return 0;
+}