Add console size functions.

README.md

@@ -5,8 +5,8 @@
 A terminal-based graphics library for both 2D and 3D graphics.\
 Works in all terminals supporting ANSI escape codes.\
 Support for Windows and UNIX.\
-C11 compliant, with no external dependencies.\
-Can read from terminal for user-interaction.
+C99 compliant, with no external dependencies.\
+Realtime input reading from terminal for user-interaction.
 
 ## Table of Contents
 

demodir/termgl_demo.c

@@ -25,7 +25,8 @@ typedef struct  STLTriangle {
 #define xstr(str_) str(str_)
 #define str(str_) #str_
 
-const char *HELPTEXT = "TermGL v" xstr(TGL_VERSION_MAJOR) "." xstr(TGL_VERSION_MINOR) "\n\
+const char *HELPTEXT_HEADER = "TermGL v" xstr(TGL_VERSION_MAJOR) "." xstr(TGL_VERSION_MINOR) " Demo Utility";
+const char *HELPTEXT_BODY = "\
 Select a Demo:\n\
 1. Utah Teapot\n\
     Renders a rotating 3D Utah Teapot.\n\
@@ -34,7 +35,7 @@ Select a Demo:\n\
 3. Mandelbrot\n\
     Renders an infinitely zooming-in Mandelbrot set.\n\
 4. Realtime Keyboard\n\
-    Displays keyboard input in realtime.\n\
+    Displays keyboard input in realtime.\
 ";
 
 void teapot_intermediate_shader(TGLTriangle *trig, void *data);
@@ -322,12 +323,19 @@ void demo_color(const unsigned res_x, const unsigned res_y, const unsigned frame
 	tgl_delete(tgl);
 }
 
+#include <windows.h>
+
 int main(int argc, char **argv)
 {
 	(void)argc;
 	(void)argv;
 
-	puts(HELPTEXT);
+	puts(HELPTEXT_HEADER);
+	unsigned col, row;
+	tglutil_get_console_size(&col, &row, true);
+	printf("Console size: %ux%u\n", col, row);
+	puts(HELPTEXT_BODY);
+
 	unsigned n = 0;
 	assert(scanf("%u", &n) == 1);
 

lib/termgl.h

@@ -247,6 +247,20 @@ void tgl3d_transform_apply(TGLTransform *transform, TGLVec3 in[3], TGLVec3 out[3
  */
 TGL_SSIZE_T tglutil_read(char *buf, size_t count);
 
+/**
+ * Stores number of console columns and rows in *col and *row respectively
+ * @param screen_buffer: true for size of screen buffer, false for size of window. On UNIX, value is ignored and assumed true.
+ * @return 0 on success, -1 on failure
+ */
+int tglutil_get_console_size(unsigned *col, unsigned *row, bool screen_buffer);
+
+/**
+ * Sets console size
+ * Only changes printable area and will not change window size if new size is larger than window
+ * @return 0 on success, -1 on failure
+ */
+int tglutil_set_console_size(unsigned col, unsigned row);
+
 #endif /* TERMGLUTIL */
 
 #ifdef __cplusplus

src/termgl.c

@@ -993,6 +993,7 @@ TGLTransform *tgl3d_get_transform(TGL *tgl)
 
 #ifdef __unix__
 #include <termios.h>
+#include <sys/ioctl.h>
 #endif
 
 TGL_SSIZE_T tglutil_read(char *buf, size_t count)
@@ -1048,4 +1049,45 @@ TGL_SSIZE_T tglutil_read(char *buf, size_t count)
 	return retval;
 }
 
+int tglutil_get_console_size(unsigned *col, unsigned *row, bool screen_buffer)
+{
+#ifdef __unix__
+	(void)screen_buffer;
+	struct winsize w;
+	int retval = ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
+	*col = w.ws_col;
+	*row = w.ws_row;
+#else /* defined(TGL_OS_WINDOWS) */
+	CONSOLE_SCREEN_BUFFER_INFO csbi;
+	int retval = GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi) ? 0 : -1;
+	if (screen_buffer) {
+		*col = csbi.dwSize.X;
+		*row = csbi.dwSize.Y;
+	} else {
+		*col = csbi.srWindow.Right - csbi.srWindow.Left + 1;
+		*row = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
+	}
+#endif
+	return retval;
+}
+
+int tglutil_set_console_size(unsigned col, unsigned row)
+{
+#ifdef __unix__
+	struct winsize w = (struct winsize) {
+		.ws_row = row,
+		.ws_col = col,
+	};
+	int retval = ioctl(STDOUT_FILENO, TIOCSWINSZ, &w);
+#else /* defined(TGL_OS_WINDOWS) */
+	COORD size = (COORD) {
+		.Y = row,
+		.X = col,
+	};
+	int retval = SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), size) ? 0 : -1;
+#endif
+	return retval;
+}
+
+
 #endif /* TERMGLUTIL */