[libgis] Adding OpenGL info query example

[Andy Spencer <andys src gnome org>]

commit 2da20b1f7feeb2b4ae280e10a445b5b55f3926bf
Author: Andy Spencer <andy753421 gmail com>
Date:   Sun May 2 06:24:09 2010 +0000

    Adding OpenGL info query example

 examples/info/.gitignore |    2 +
 examples/info/info.c     |   76 ++++++++++++++++++++++++++++++++++++++++++++++
 examples/info/mkfile     |   14 ++++++++
 3 files changed, 92 insertions(+), 0 deletions(-)
---
diff --git a/examples/info/.gitignore b/examples/info/.gitignore
new file mode 100644
index 0000000..c226b5c
--- /dev/null
+++ b/examples/info/.gitignore
@@ -0,0 +1,2 @@
+info
+info.exe
diff --git a/examples/info/info.c b/examples/info/info.c
new file mode 100644
index 0000000..cd4fe71
--- /dev/null
+++ b/examples/info/info.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2009-2010 Andy Spencer <andy753421 gmail com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+#include <GL/glut.h>
+
+#define COUNT(arr) (sizeof(arr)/sizeof(arr[0]))
+
+int main(int argc, char **argv)
+{
+	glutInit(&argc, argv);
+	glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
+	glutInitWindowSize(250,250);
+	glutInitWindowPosition(100,100);
+	glutCreateWindow("Hello World!");
+
+
+	/* Query max size */
+	GLint size;
+	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
+	printf("\nGL_MAX_TEXTURE_SIZE = %d\n", size);
+
+
+	/* Test extensions */
+	const char *exts[] = {
+		"GL_ARB_texture_rectangle",
+		"GL_ARB_does_not_exist",
+	};
+	printf("\nChecking some extensions...\n");
+	const char *avail  = (char*)glGetString(GL_EXTENSIONS);
+	for (int i = 0; i < COUNT(exts); i++)
+		printf("\t%s: %s\n", exts[i],
+			strstr(avail,exts[i]) ? "OK" : "Error");
+
+
+	/* Test sample image */
+	GLint sizes[][2] = {
+		{3400, 1600},
+		{1024, 1024},
+		{4096, 4096},
+		{8192, 8192},
+	};
+	printf("\nTrying some sizes...\n");
+	for (int i = 0; i < COUNT(sizes); i++) {
+		GLint width  = sizes[i][0];
+		GLint height = sizes[i][1];
+		printf("\t%dx%d: ", width, height);
+		glTexImage2D(GL_PROXY_TEXTURE_2D, 0, 4, width, height, 0,
+				GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+		glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_WIDTH,  &width);
+		glGetTexLevelParameteriv(GL_PROXY_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &height);
+		printf("%s\n", width && height ? "OK" : "Error");
+	}
+
+
+	/* Wait */
+	printf("\nPress any key to exit..\n");
+	getchar();
+}
diff --git a/examples/info/mkfile b/examples/info/mkfile
new file mode 100644
index 0000000..ced3f35
--- /dev/null
+++ b/examples/info/mkfile
@@ -0,0 +1,14 @@
+MKSHELL=/usr/lib/plan9/bin/rc
+PROGS=info info.exe
+default:V: all info-run
+
+info_libs=-lGL -lGLU -lglut
+
+info.exe: info.c
+	i686-pc-mingw32-gcc -o $target $prereq \
+		$CFLAGS -DFREEGLUT_STATIC -static \
+		-lfreeglut_static -lopengl32 -lwinmm -lgdi32
+info.exe-run: info.exe
+	wine $prereq
+
+<$HOME/lib/mkcommon