/*
 * vp_check.c
 *
 * Consistency and error checking routines.
 *
 * Copyright (c) 1994 The Board of Trustees of The Leland Stanford
 * Junior University.  All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation for any purpose is hereby granted without fee, provided
 * that the above copyright notice and this permission notice appear in
 * all copies of this software and that you do not sell the software.
 * Commercial licensing is available by contacting the author.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Author:
 *    Phil Lacroute
 *    Computer Systems Laboratory
 *    Electrical Engineering Dept.
 *    Stanford University
 */

/*
 * $Date$
 * $Revision$
 */

#include "vp_global.h"

/* error strings for vpGetErrorString() */
static char *ErrorString[] = {
    "limit exceeded",
    "singular matrix or vector",
    "I/O error",
    "invalid buffer size",
    "invalid image definition",
    "invalid shader definition",
    "invalid classifier definition",
    "invalid volume definition",
    "invalid voxel definition",
    "invalid option",
    "argument out of range",
    "invalid file",
    "cannot compute shadow buffer",
};

/*
 * VPCheckVoxelFields
 *
 * Check the voxel field information for validity.
 */

vpResult
VPCheckVoxelFields(vpc)
vpContext *vpc;
{
    int f;
    int size, offset;

    if (vpc->raw_bytes_per_voxel <= 0)
	return(VPSetError(vpc, VPERROR_BAD_VOXEL));
    if (vpc->num_voxel_fields <= 0)
	return(VPSetError(vpc, VPERROR_BAD_VOXEL));
    for (f = 0; f < vpc->num_voxel_fields; f++) {
	size = vpc->field_size[f];
	offset = vpc->field_offset[f];
	if (size != 1 && size != 2 && size != 4)
	    return(VPSetError(vpc, VPERROR_BAD_VOXEL));
	if (offset < 0 || offset + size > vpc->raw_bytes_per_voxel)
	    return(VPSetError(vpc, VPERROR_BAD_VOXEL));
	if (f > 0 && offset < vpc->field_size[f-1] + vpc->field_offset[f-1])
	    return(VPSetError(vpc, VPERROR_BAD_VOXEL));
    }
    return(VP_OK);
}

/*
 * VPCheckRawVolume
 *
 * Check the raw volume for consistency.
 */

vpResult
VPCheckRawVolume(vpc)
vpContext *vpc;
{
    int size, offset, retcode;

    if ((retcode = VPCheckVoxelFields(vpc)) != VP_OK)
	return(retcode);
    if (vpc->xlen <= 0 || vpc->ylen <= 0 || vpc->zlen <= 0)
	return(VPSetError(vpc, VPERROR_BAD_VOLUME));
    if (vpc->raw_voxels == NULL)
	return(VPSetError(vpc, VPERROR_BAD_VOLUME));
    if (vpc->raw_bytes_per_voxel * vpc->xlen * vpc->ylen * vpc->zlen !=
	vpc->raw_voxels_size)
	return(VPSetError(vpc, VPERROR_BAD_VOLUME));
    return(VP_OK);
}

/*
 * VPCheckClassifiedVolume
 *
 * Check the classified volume for consistency.
 */

vpResult
VPCheckClassifiedVolume(vpc, axis)
vpContext *vpc;
int axis;
{
    int retcode;

    if ((retcode = VPCheckVoxelFields(vpc)) != VP_OK)
	return(retcode);
    if (vpc->xlen <= 0 || vpc->ylen <= 0 || vpc->zlen <= 0)
	return(VPSetError(vpc, VPERROR_BAD_VOLUME));
    if (vpc->rle_bytes_per_voxel == 0)
	return(VPSetError(vpc, VPERROR_BAD_VOLUME));
    switch (axis) {
    case VP_X_AXIS:
	if (vpc->rle_x == NULL)
	    return(VPSetError(vpc, VPERROR_BAD_VOLUME));
	ASSERT(vpc->rle_x->ilen == vpc->ylen);
	ASSERT(vpc->rle_x->jlen == vpc->zlen);
	ASSERT(vpc->rle_x->klen == vpc->xlen);
	break;
    case VP_Y_AXIS:
	if (vpc->rle_y == NULL)
	    return(VPSetError(vpc, VPERROR_BAD_VOLUME));
	ASSERT(vpc->rle_y->ilen == vpc->zlen);
	ASSERT(vpc->rle_y->jlen == vpc->xlen);
	ASSERT(vpc->rle_y->klen == vpc->ylen);
	break;
    case VP_Z_AXIS:
	if (vpc->rle_z == NULL)
	    return(VPSetError(vpc, VPERROR_BAD_VOLUME));
	ASSERT(vpc->rle_z->ilen == vpc->xlen);
	ASSERT(vpc->rle_z->jlen == vpc->ylen);
	ASSERT(vpc->rle_z->klen == vpc->zlen);
	break;
    default:
	VPBug("bad axis in VPCheckClassifiedVolume");
    }
    return(VP_OK);
}

/*
 * VPCheckClassifier
 *
 * Check the classification parameters for consistency.
 */

vpResult
VPCheckClassifier(vpc)
vpContext *vpc;
{
    int p, f;
    int size, offset, retcode;

    if ((retcode = VPCheckVoxelFields(vpc)) != VP_OK)
	return(retcode);
    if (vpc->num_shade_fields <= 0 ||
	vpc->num_shade_fields > vpc->num_voxel_fields)
	return(VPSetError(vpc, VPERROR_BAD_VOXEL));
    if (vpc->num_clsfy_params <= 0 ||
	vpc->num_clsfy_params > vpc->num_voxel_fields)
	return(VPSetError(vpc, VPERROR_BAD_VOXEL));
    for (p = 0; p < vpc->num_clsfy_params; p++) {
	f = vpc->param_field[p];
	if (f < 0 || f >= vpc->num_voxel_fields)
	    return(VPSetError(vpc, VPERROR_BAD_CLASSIFIER));
	if (vpc->clsfy_table[p] == NULL || vpc->clsfy_table_size[p] !=
	    (vpc->field_max[f]+1)*sizeof(float))
	    return(VPSetError(vpc, VPERROR_BAD_CLASSIFIER));
	if (p > 0 && f <= vpc->param_field[p-1])
	    return(VPSetError(vpc, VPERROR_BAD_CLASSIFIER));
    }
    return(VP_OK);
}

/*
 * VPCheckShader
 *
 * Check the shading parameters for consistency.
 */

vpResult
VPCheckShader(vpc)
vpContext *vpc;
{
    if (vpc->shading_mode == LOOKUP_SHADER) {
	if (vpc->color_field < 0 ||
	    vpc->color_field >= vpc->num_voxel_fields ||
	    vpc->color_field >= vpc->num_shade_fields)
	    return(VPSetError(vpc, VPERROR_BAD_SHADER));
	if (vpc->shade_color_table == NULL)
	    return(VPSetError(vpc, VPERROR_BAD_SHADER));
	if (vpc->shade_color_table_size != vpc->color_channels*sizeof(float)*
		(vpc->field_max[vpc->color_field]+1)*vpc->num_materials)
	    return(VPSetError(vpc, VPERROR_BAD_SHADER));
	if (vpc->field_size[vpc->color_field] != 2)
	    return(VPSetError(vpc, VPERROR_BAD_SHADER));
	if (vpc->num_materials < 1)
	    return(VPSetError(vpc, VPERROR_BAD_SHADER));
	if (vpc->num_materials > 1) {
	    if (vpc->weight_field < 0 ||
		vpc->weight_field >= vpc->num_voxel_fields ||
		vpc->weight_field >= vpc->num_shade_fields)
		return(VPSetError(vpc, VPERROR_BAD_SHADER));
	    if (vpc->shade_weight_table == NULL)
		return(VPSetError(vpc, VPERROR_BAD_SHADER));
	    if (vpc->shade_weight_table_size !=
		(vpc->field_max[vpc->weight_field]+1) * sizeof(float) * 
		vpc->num_materials)
		return(VPSetError(vpc, VPERROR_BAD_SHADER));
	    if (vpc->field_size[vpc->weight_field] != 1)
		return(VPSetError(vpc, VPERROR_BAD_SHADER));
	}
    }
    return(VP_OK);
}

/*
 * VPCheckImage
 *
 * Check the image buffer for validity.
 */

vpResult
VPCheckImage(vpc)
vpContext *vpc;
{
    if (vpc->image == NULL || vpc->image_width <= 0 || vpc->image_height <= 0)
	return(VPSetError(vpc, VPERROR_BAD_IMAGE));
    switch (vpc->pixel_type) {
    case VP_ALPHA:
	break;
    case VP_LUMINANCE:
    case VP_LUMINANCEA:
	if (vpc->color_channels != 1)
	    return(VPSetError(vpc, VPERROR_BAD_OPTION));
	break;
    case VP_RGB:
    case VP_BGR:
    case VP_RGBA:
    case VP_ABGR:
	if (vpc->color_channels != 3)
	    return(VPSetError(vpc, VPERROR_BAD_OPTION));
	break;
    default:
	return(VPSetError(vpc, VPERROR_BAD_OPTION));
    }
    return(VP_OK);
}

/*
 * VPCheckShadows
 *
 * Check the shadow specification for validity.
 */

vpResult
VPCheckShadows(vpc)
vpContext *vpc;
{
    if (vpc->enable_shadows) {
	if (vpc->shadow_light_num < VP_LIGHT0 ||
	    vpc->shadow_light_num > VP_LIGHT5)
	    return(VPSetError(vpc, VPERROR_BAD_OPTION));
	if (!vpc->light_enable[vpc->shadow_light_num - VP_LIGHT0])
	    vpc->enable_shadows = 0;
	if (vpc->shadow_color_table_size != vpc->shade_color_table_size ||
	    vpc->shadow_color_table == NULL)
	    return(VPSetError(vpc, VPERROR_BAD_SIZE));
    }
    return(VP_OK);
}

/*
 * vpGetError
 *
 * Return the error code from the first invalid command since the last
 * call to vpGetError().
 */

vpResult
vpGetError(vpc)
vpContext *vpc;
{
    vpResult code;

    code = vpc->error_code;
    vpc->error_code = VP_OK;
    return(code);
}

/*
 * vpGetErrorString
 *
 * Return a descriptive string for an error code.
 */

char *
vpGetErrorString(code)
vpResult code;
{
    if (code == VP_OK)
	return("no error");
    else if (code < VPERROR_FIRST || code > VPERROR_LAST)
	return(NULL);
    else
	return(ErrorString[code - VPERROR_FIRST]);
}

/*
 * VPSetError
 *
 * Set the error code in vpc.
 */

vpResult
VPSetError(vpc, code)
vpContext *vpc;
vpResult code;
{
    if (vpc->error_code == VP_OK)
	vpc->error_code = code;
    return(code);
}