/*
 * Copyright © 2010 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 fbo-readpixels-small.c
 *
 * Tests that PBO blit readpixels on a 2x2 FBO works correctly.  Based
 * on a description of a failure in clutter and figuring out the associated
 * bug.
 *
 * https://bugs.freedesktop.org/show_bug.cgi?id=25921
 */

#include "piglit-util-gl.h"

#define BUF_WIDTH 8
#define BUF_HEIGHT 8

PIGLIT_GL_TEST_CONFIG_BEGIN

	config.supports_gl_compat_version = 10;

	config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
	config.khr_no_error_support = PIGLIT_NO_ERRORS;

PIGLIT_GL_TEST_CONFIG_END

static void
make_fbo(GLuint *fbo, GLuint *tex)
{
	GLenum status;

	glGenTextures(1, tex);
	glBindTexture(GL_TEXTURE_2D, *tex);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA,
		     2, 2, 0,
		     GL_RGBA, GL_UNSIGNED_BYTE, NULL);

	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	glGenFramebuffersEXT(1, fbo);
	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, *fbo);
	glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
				  GL_COLOR_ATTACHMENT0_EXT,
				  GL_TEXTURE_2D,
				  *tex,
				  0);
	if (!piglit_check_gl_error(GL_NO_ERROR))
		piglit_report_result(PIGLIT_FAIL);

	status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
	if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
		fprintf(stderr, "framebuffer incomplete (status = 0x%04x)\n",
			status);
		abort();
	}
}

static GLboolean
probe(int x, int y, uint8_t *expected, uint8_t *observed)
{
	if (expected[0] != observed[0] ||
	    expected[1] != observed[1] ||
	    expected[2] != observed[2]) {
		printf("Probe color at (%i,%i)\n", x, y);
		printf("  Expected: b = 0x%02x  g = 0x%02x  r = 0x%02x  a = 0x%02x\n",
				expected[0], expected[1], expected[2], expected[3]);
		printf("  Observed: b = 0x%02x  g = 0x%02x  r = 0x%02x  a = 0x%02x\n",
				observed[0], observed[1], observed[2], observed[3]);

		return GL_FALSE;
	} else {
		return GL_TRUE;
	}
}

enum piglit_result
piglit_display(void)
{
	GLboolean pass = GL_TRUE;
	GLuint fbo, tex, pbo;
	uint8_t *addr;
	static uint8_t green[] = {0x00, 0xFF, 0x00, 0x00};
	static uint8_t blue[]  = {0xFF, 0x00, 0x00, 0x00};

	make_fbo(&fbo, &tex);

	glClear(GL_COLOR_BUFFER_BIT);

	glGenBuffersARB(1, &pbo);
	glBindBufferARB(GL_PIXEL_PACK_BUFFER, pbo);
	glBufferDataARB(GL_PIXEL_PACK_BUFFER, 4 * 4, NULL, GL_STREAM_DRAW_ARB);
	glPixelStorei(GL_PACK_ALIGNMENT, 1);

	glViewport(0, 0, 2, 2);
	piglit_ortho_projection(2, 2, GL_FALSE);

	/* bottom: green.  top: blue. */
	glColor4f(0.0, 1.0, 0.0, 0.0);
	piglit_draw_rect(0, 0, 2, 1);
	glColor4f(0.0, 0.0, 1.0, 0.0);
	piglit_draw_rect(0, 1, 2, 1);

	/* Read the whole buffer. */
	glReadPixels(0, 0, 2, 2,
		     GL_BGRA, GL_UNSIGNED_BYTE, (void *)(uintptr_t)0);
	addr = glMapBufferARB(GL_PIXEL_PACK_BUFFER, GL_READ_ONLY_ARB);

	pass &= probe(0, 0, green, addr);
	pass &= probe(1, 0, green, addr + 4);
	pass &= probe(0, 1, blue,  addr + 8);
	pass &= probe(1, 1, blue,  addr + 12);
	glUnmapBufferARB(GL_PIXEL_PACK_BUFFER);

	/* Read with an offset. */
	glReadPixels(1, 0, 1, 1,
		     GL_BGRA, GL_UNSIGNED_BYTE, (void *)(uintptr_t)4);
	addr = glMapBufferARB(GL_PIXEL_PACK_BUFFER, GL_READ_ONLY_ARB);
	pass &= probe(1, 0, green, addr + 4);
	glUnmapBufferARB(GL_PIXEL_PACK_BUFFER);

	/* Read with an offset. */
	glReadPixels(1, 1, 1, 1,
		     GL_BGRA, GL_UNSIGNED_BYTE, (void *)(uintptr_t)4);
	addr = glMapBufferARB(GL_PIXEL_PACK_BUFFER, GL_READ_ONLY_ARB);
	pass &= probe(1, 1, blue, addr + 4);
	glUnmapBufferARB(GL_PIXEL_PACK_BUFFER);

	glDeleteBuffersARB(1, &pbo);

	glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, piglit_winsys_fbo);

	glViewport(0, 0, piglit_width, piglit_height);
	piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);

	glBindTexture(GL_TEXTURE_2D, tex);
	glEnable(GL_TEXTURE_2D);
	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

	piglit_draw_rect_tex(0, 0, piglit_width, piglit_height,
			     0, 0, 1, 1);
	glDisable(GL_TEXTURE_2D);

	glDeleteFramebuffersEXT(1, &fbo);
	glDeleteTextures(1, &tex);

	piglit_present_results();

	return pass ? PIGLIT_PASS : PIGLIT_FAIL;
}

void piglit_init(int argc, char **argv)
{
	piglit_require_extension("GL_EXT_framebuffer_object");
	piglit_require_extension("GL_ARB_pixel_buffer_object");

	glDisable(GL_DITHER);
}