/*
 * Copyright © 2009 Intel Corporation
 *
 * 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
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS 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.
 *
 * Authors:
 *    Eric Anholt <eric@anholt.net>
 */

/** @file depth_clamp.c
 * Tests ARB_depth_clamp functionality by drawing side-by-side triangles,
 * lines, points, and raster images that go behind the near plane, and
 * testing that when DEPTH_CLAMP is enabled they get rasterized as they should.
 *
 * An extension of this test would be to test that the depth values are
 * correctly clamped to the near/far plane, not just unclipped, and to test
 * the same operations against the far plane.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <GL/glew.h>
#if defined(__APPLE__)
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif

#define WIN_WIDTH 100
#define WIN_HEIGHT 100

static void
init(void)
{
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();
	glOrtho(0, WIN_WIDTH, 0, WIN_HEIGHT, -1, 1);

	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();
}

static void
display(void)
{
	GLfloat buf[] = {1.0};

	glDisable(GL_DITHER);

	glDisable(GL_ALPHA_TEST);
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glClear(GL_COLOR_BUFFER_BIT);

	glEnable(GL_ALPHA_TEST);
	glAlphaFunc(GL_ALWAYS, 0.5);

	glColor4f(1.0, 1.0, 1.0, 0.3);
	glRasterPos2f((float)0.0, (float)0.0);
	glDrawPixels(1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, buf);

	glColor4f(1.0, 1.0, 1.0, 0.5);
	glRasterPos2f((float)1.0, (float)0.0);
	glDrawPixels(1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, buf);

	glutSwapBuffers();
}

int main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);
	glutInitWindowSize(WIN_WIDTH, WIN_HEIGHT);
	glutCreateWindow("drawpix_depth_alpha");
	glutDisplayFunc(display);

	init();

	glutMainLoop();

	return 0;

}