From 673c03f31ddd2b6ed646ec6fc0c225833201bd65 Mon Sep 17 00:00:00 2001
From: Eleni Maria Stea <estea@igalia.com>
Date: Fri, 4 May 2018 20:46:31 +0300
Subject: [PATCH] added check for compressed format support
 (ARB_internalformat_query2.txt)

---
 Makefile |    2 +-
 main.c   |    7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 84363ff..cd3d9e2 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ obj = main.o
 bin = test
 
 CFLAGS = -pedantic -Wall -g
-LDFLAGS = -lGL -lglut
+LDFLAGS = -lGLEW -lGL -lglut
 
 $(bin): $(obj)
 	$(CC) -o $@ $(obj) $(LDFLAGS)
diff --git a/main.c b/main.c
index 32da284..a023307 100644
--- a/main.c
+++ b/main.c
@@ -3,6 +3,7 @@
 #include <string.h>
 #include <errno.h>
 #include <assert.h>
+#include <GL/glew.h>
 #include <GL/freeglut.h>
 
 #undef USE_SRGB
@@ -45,6 +46,8 @@ int main(int argc, char **argv)
 	glutReshapeFunc(reshape);
 	glutKeyboardFunc(keyb);
 
+	glewInit();
+
 	if(init() == -1) {
 		return 1;
 	}
@@ -353,7 +356,11 @@ void print_compressed_formats(void)
 	glGetIntegerv(GL_COMPRESSED_TEXTURE_FORMATS, fmtlist);
 
 	for(i=0; i<num_fmt; i++) {
+		printf("\n");
 		printf(" %05x: %s\n", fmtlist[i], fmtstr(fmtlist[i]));
+		GLint params;
+		glGetInternalformativ(GL_TEXTURE_2D, fmtlist[i], GL_TEXTURE_COMPRESSED, 1, &params);
+		printf("the format is %s\n", params == GL_TRUE ? "compressed" : "not compressed");
 	}
 	free(fmtlist);
 }
-- 
1.7.10.4