Test the overhead of just calling a GL function. The Python script is
a helper to do multiple runs and compare the results.
diff --git a/progs/tests/api_speed.c b/progs/tests/api_speed.c
new file mode 100644
index 0000000..f42c73d
--- /dev/null
+++ b/progs/tests/api_speed.c
@@ -0,0 +1,146 @@
+/*
+ * (C) Copyright IBM Corporation 2002
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file api_speed.c
+ * Simple test to measure the overhead of making GL calls.
+ *
+ * The main purpose of this test is to measure the difference in calling
+ * overhead of different dispatch methods. Since it uses asm/timex.h to
+ * access the Pentium's cycle counters, it will probably only compile on
+ * Linux (though most architectures have a get_cycles function in timex.h).
+ * That is why it isn't in the default Makefile.
+ *
+ * \author Ian Romanick <idr@us.ibm.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glext.h>
+#include <GL/glut.h>
+
+#define inline __inline__
+#include <asm/timex.h>
+
+static float Width = 400;
+static float Height = 400;
+static unsigned count = 1000000;
+
+
+static void Idle( void )
+{
+ glutPostRedisplay();
+}
+
+#define DO_FUNC(f,p) \
+ do { \
+ t0 = get_cycles(); \
+ for ( i = 0 ; i < count ; i++ ) { \
+ f p ; \
+ } \
+ t1 = get_cycles(); \
+ printf("%u calls to % 20s required %llu cycles.\n", count, # f, t1 - t0); \
+ } while( 0 )
+
+/**
+ * Main display function. This is the place to add more API calls.
+ */
+static void Display( void )
+{
+ int i;
+ const float v[3] = { 1.0, 0.0, 0.0 };
+ cycles_t t0;
+ cycles_t t1;
+
+ glBegin(GL_TRIANGLE_STRIP);
+
+ DO_FUNC( glColor3fv, (v) );
+ DO_FUNC( glNormal3fv, (v) );
+ DO_FUNC( glTexCoord2fv, (v) );
+ DO_FUNC( glTexCoord3fv, (v) );
+ DO_FUNC( glMultiTexCoord2fv, (GL_TEXTURE0, v) );
+ DO_FUNC( glMultiTexCoord2f, (GL_TEXTURE0, 0.0, 0.0) );
+ DO_FUNC( glFogCoordfv, (v) );
+ DO_FUNC( glFogCoordf, (0.5) );
+
+ glEnd();
+
+ exit(0);
+}
+
+
+static void Reshape( int width, int height )
+{
+ Width = width;
+ Height = height;
+ glViewport( 0, 0, width, height );
+ glMatrixMode( GL_PROJECTION );
+ glLoadIdentity();
+ glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
+ glMatrixMode( GL_MODELVIEW );
+ glLoadIdentity();
+}
+
+
+static void Key( unsigned char key, int x, int y )
+{
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 27:
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+int main( int argc, char *argv[] )
+{
+ glutInit( &argc, argv );
+ glutInitWindowSize( (int) Width, (int) Height );
+ glutInitWindowPosition( 0, 0 );
+
+ glutInitDisplayMode( GLUT_RGB );
+
+ glutCreateWindow( argv[0] );
+
+ if ( argc > 1 ) {
+ count = strtoul( argv[1], NULL, 0 );
+ if ( count == 0 ) {
+ fprintf( stderr, "Usage: %s [iterations]\n", argv[0] );
+ exit(1);
+ }
+ }
+
+ glutReshapeFunc( Reshape );
+ glutKeyboardFunc( Key );
+ glutDisplayFunc( Display );
+ glutIdleFunc( Idle );
+
+ glutMainLoop();
+ return 0;
+}