/*
 * Copyright (C) 2009  VMware, Inc.  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
 * 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 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
 * VMWARE 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.
 */

/**
 * Measure glReadPixels speed.
 * XXX also read into a PBO?
 * XXX also read from FBOs?
 *
 * Brian Paul
 * 23 Sep 2009
 */

#include <string.h>
#include "common.h"
#include "piglit-util-gl.h"

#define WINDOW_SIZE 1000


PIGLIT_GL_TEST_CONFIG_BEGIN

	config.supports_gl_compat_version = 10;
	config.window_width = WINDOW_SIZE;
	config.window_height = WINDOW_SIZE;
	config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;

PIGLIT_GL_TEST_CONFIG_END

static GLuint VBO;

static const GLboolean DrawPoint = GL_TRUE;

static const GLfloat Vertex0[2] = { 0.0, 0.0 };

static GLenum HaveDepthStencil;

static GLenum ReadFormat, ReadType;
static GLint ReadWidth, ReadHeight;
static GLvoid *ReadBuffer;


void
piglit_init(int argc, char **argv)
{
	/* setup VBO */
	glGenBuffersARB(1, &VBO);
	glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
	glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(Vertex0), Vertex0, GL_STATIC_DRAW_ARB);
	glVertexPointer(2, GL_FLOAT, sizeof(Vertex0), (void *) 0);
	glEnableClientState(GL_VERTEX_ARRAY);

	glPixelStorei(GL_PACK_ALIGNMENT, 1);

	HaveDepthStencil = piglit_is_extension_supported("GL_EXT_packed_depth_stencil");

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
	glEnable(GL_DEPTH_TEST);
	glEnable(GL_STENCIL_TEST);
}


static void
ReadPixels(unsigned count)
{
	unsigned i;
	for (i = 0; i < count; i++) {
		/* read from random pos */
		GLint x, y;

		x = piglit_width - ReadWidth;
		y = piglit_height - ReadHeight;
		if (x > 0)
			x = rand() % x;
		if (y > 0)
			y = rand() % y;

		if (DrawPoint)
			glDrawArrays(GL_POINTS, 0, 1);

		glReadPixels(x, y, ReadWidth, ReadHeight,
		             ReadFormat, ReadType, ReadBuffer);
	}
	glFinish();
}


static const GLsizei Sizes[] = {
	10,
	100,
	500,
	1000,
	0
};


static const struct {
	GLenum format;
	GLenum type;
	const char *name;
	GLuint pixel_size;
} DstFormats[] = {
	{ GL_RGBA, GL_UNSIGNED_BYTE,           "RGBA/ubyte", 4 },
	{ GL_BGRA, GL_UNSIGNED_BYTE,           "BGRA/ubyte", 4 },
	{ GL_RGB, GL_UNSIGNED_SHORT_5_6_5,     "RGB/565", 2 },
	{ GL_LUMINANCE, GL_UNSIGNED_BYTE,      "L/ubyte", 1 },
	{ GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, "Z/uint", 4 },
	{ GL_DEPTH_STENCIL_EXT, GL_UNSIGNED_INT_24_8_EXT, "Z+S/uint", 4 },
	{ 0, 0, NULL, 0 }
};



enum piglit_result
piglit_display(void)
{
	double rate, mbPerSec;
	int fmt, sz;

	/* loop over formats */
	for (fmt = 0; DstFormats[fmt].format; fmt++) {
		ReadFormat = DstFormats[fmt].format;
		ReadType = DstFormats[fmt].type;

		/* loop over sizes */
		for (sz = 0; Sizes[sz]; sz++) {
			int imgSize;

			ReadWidth = ReadHeight = Sizes[sz];
			imgSize = ReadWidth * ReadHeight * DstFormats[fmt].pixel_size;
			ReadBuffer = malloc(imgSize);

			if (ReadFormat == GL_DEPTH_STENCIL_EXT && !HaveDepthStencil) {
				rate = 0.0;
				mbPerSec = 0.0;
			}
			else {
				rate = perf_measure_cpu_rate(ReadPixels, 1.0);
				mbPerSec = rate * imgSize / (1024.0 * 1024.0);
			}

			printf("glReadPixels(%d x %d, %s): %.1f images/sec, %.1f Mpixels/sec\n",
			       ReadWidth, ReadHeight,
			       DstFormats[fmt].name, rate, mbPerSec);

			free(ReadBuffer);
		}
	}

	exit(0);
	return PIGLIT_SKIP;
}
