#include "HGPng.h"
#include "../base/HGInc.h"
#include "png.h"
#include "pngstruct.h"
#include "pnginfo.h"
#include "pngpriv.h"

HGResult HGAPI HGImgFmt_CheckPngFile(const HGChar* fileName, HGBool* isPng)
{
	if (NULL == fileName || NULL == isPng)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	HGPngLoadInfo info;
	HGResult ret = HGImgFmt_LoadPngImage(fileName, &info, 0, 0, NULL);
	*isPng = (HGBASE_ERR_OK == ret ? HGTRUE : HGFALSE);
	return HGBASE_ERR_OK;
}

HGResult HGAPI HGImgFmt_LoadPngImage(const HGChar* fileName, HGPngLoadInfo* info,
	HGUInt imgType, HGUInt imgOrigin, HGImage* image)
{
	if (NULL == fileName)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	if (NULL == image)
	{
		if (0 != imgType || 0 != imgOrigin)
		{
			return HGBASE_ERR_INVALIDARG;
		}
	}
	else
	{
		if (0 != imgType && HGBASE_IMGTYPE_GRAY != imgType && HGBASE_IMGTYPE_RGB != imgType
			&& HGBASE_IMGTYPE_RGBA != imgType && HGBASE_IMGTYPE_BGR != imgType
			&& HGBASE_IMGTYPE_BGRA != imgType)
		{
			return HGBASE_ERR_INVALIDARG;
		}

		if (HGBASE_IMGORIGIN_TOP != imgOrigin && HGBASE_IMGORIGIN_BOTTOM != imgOrigin)
		{
			return HGBASE_ERR_INVALIDARG;
		}
	}

	FILE* file = fopen(fileName, "rb");
	if (NULL == file)
	{
		return HGBASE_ERR_ACCESSDENIED;
	}

	png_byte buf[8] = { 0 };
	if (fread(buf, 1, 8, file) != 8)
	{
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	if (0 != png_sig_cmp(buf, 0, 8))
	{
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (NULL == png_ptr)
	{
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	png_infop info_ptr = png_create_info_struct(png_ptr);
	if (NULL == info_ptr)
	{
		png_destroy_read_struct(&png_ptr, NULL, NULL);
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	HGImage image2 = NULL;
	uint8_t* buffer = NULL;
	uint8_t** rowPointers = NULL;

	int jmpResult = setjmp(png_jmpbuf(png_ptr));
	if (0 != jmpResult)
	{
		free(rowPointers);
		rowPointers = NULL;
		free(buffer);
		buffer = NULL;
		HGBase_DestroyImage(image2);
		image2 = NULL;
		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
		fclose(file);
		file = NULL;
		return (HGResult)jmpResult;
	}

#if defined(HG_CMP_MSC)
	_fseeki64(file, 0, SEEK_SET);
#else
	fseeko64(file, 0, SEEK_SET);
#endif
	png_init_io(png_ptr, file);
	png_read_info(png_ptr, info_ptr);

	if (NULL != info)
	{
		info->width = info_ptr->width;
		info->height = info_ptr->height;
		info->bitDepth = info_ptr->bit_depth;
		info->colorType = info_ptr->color_type;
		info->channels = info_ptr->channels;
		info->filterType = info_ptr->filter_type;
		info->InterlaceType = info_ptr->interlace_type;
		info->compressionType = info_ptr->compression_type;
		info->pixelDepth = info_ptr->pixel_depth;
		info->physUnitType = info_ptr->phys_unit_type;
		info->xPixelsPerUnit = info_ptr->x_pixels_per_unit;
		info->yPixelsPerUnit = info_ptr->y_pixels_per_unit;
	}

	if (NULL != image)
	{
		png_set_scale_16(png_ptr);
		png_set_expand(png_ptr);

		png_set_interlace_handling(png_ptr);
		png_read_update_info(png_ptr, info_ptr);

		buffer = (uint8_t*)malloc((uintptr_t)info_ptr->rowbytes * (uintptr_t)info_ptr->height);
		if (NULL == buffer)
		{
			longjmp(png_jmpbuf(png_ptr), (int)HGBASE_ERR_FAIL);
		}

		rowPointers = (uint8_t**)malloc(info_ptr->height * sizeof(png_bytep));
		if (NULL == rowPointers)
		{
			longjmp(png_jmpbuf(png_ptr), (int)HGBASE_ERR_FAIL);
		}

		//#pragma omp parallel for
		for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; ++i)
		{
			rowPointers[i] = buffer + (uintptr_t)i * (uintptr_t)info_ptr->rowbytes;
		}

		png_read_image(png_ptr, rowPointers);
		png_read_end(png_ptr, info_ptr);

		if (0 == imgType)
		{
			if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type || PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type)
			{
				imgType = HGBASE_IMGTYPE_RGBA;
			}
			else if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				imgType = HGBASE_IMGTYPE_GRAY;
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB == info_ptr->color_type);
				imgType = HGBASE_IMGTYPE_RGB;
			}
		}

		if (HGBASE_ERR_OK != HGBase_CreateImage(info_ptr->width, info_ptr->height, imgType, imgOrigin, &image2))
		{
			longjmp(png_jmpbuf(png_ptr), (int)HGBASE_ERR_FAIL);
		}

		if (1 == info_ptr->phys_unit_type)
		{
			uint32_t xDpi = (uint32_t)((double)info_ptr->x_pixels_per_unit / 39.3700787 + 0.5);
			uint32_t yDpi = (uint32_t)((double)info_ptr->y_pixels_per_unit / 39.3700787 + 0.5);
			HGBase_SetImageDpi(image2, xDpi, yDpi);
		}

		uint8_t* data;
		HGBase_GetImageData(image2, &data);
		HGImageInfo imgInfo;
		HGBase_GetImageInfo(image2, &imgInfo);

		HGByte* dest = data;
		HGSize destStep = (HGSize)imgInfo.widthStep;
		if (HGBASE_IMGORIGIN_BOTTOM == imgOrigin)
		{
			dest = data + (HGUSize)(imgInfo.height - 1) * (HGUSize)imgInfo.widthStep;
			destStep = -(HGSize)imgInfo.widthStep;
		}

		if (HGBASE_IMGTYPE_GRAY == imgType)
		{
			if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;
					memcpy(pDestEx, pEx, info_ptr->width);
				}
			}
			else if (PNG_COLOR_TYPE_RGB == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 3;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t value = (pEx[0] * 76 + pEx[1] * 150 + pEx[2] * 30) >> 8;
						*pDestEx = value;

						pEx += 3;
						++pDestEx;
					}
				}
			}
			else if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 2;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						*pDestEx = *pEx;
						pEx += 2;
						++pDestEx;
					}
				}
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type);

				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 4;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t value = (pEx[0] * 76 + pEx[1] * 150 + pEx[2] * 30) >> 8;
						*pDestEx = value;

						pEx += 4;
						++pDestEx;
					}
				}
			}
		}
		else if (HGBASE_IMGTYPE_RGB == imgType)
		{
			if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pDestEx[1] = pDestEx[2] = *pEx;
						++pEx;
						pDestEx += 3;
					}
				}
			}
			else if (PNG_COLOR_TYPE_RGB == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;
					memcpy(pDestEx, pEx, info_ptr->width * 3);
				}
			}
			else if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 2;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pDestEx[1] = pDestEx[2] = *pEx;
						pEx += 2;
						pDestEx += 3;
					}
				}
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type);

				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 4;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pEx[0];
						pDestEx[1] = pEx[1];
						pDestEx[2] = pEx[2];

						pEx += 4;
						pDestEx += 3;
					}
				}
			}
		}
		else if (HGBASE_IMGTYPE_BGR == imgType)
		{
			if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pDestEx[1] = pDestEx[2] = *pEx;
						++pEx;
						pDestEx += 3;
					}
				}
			}
			else if (PNG_COLOR_TYPE_RGB == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 3;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pEx[2];
						pDestEx[1] = pEx[1];
						pDestEx[2] = pEx[0];

						pEx += 3;
						pDestEx += 3;
					}
				}
			}
			else if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 2;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pDestEx[1] = pDestEx[2] = *pEx;
						pEx += 2;
						pDestEx += 3;
					}
				}
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type);

				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 4;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						pDestEx[0] = pEx[2];
						pDestEx[1] = pEx[1];
						pDestEx[2] = pEx[0];

						pEx += 4;
						pDestEx += 3;
					}
				}
			}
		}
		else if (HGBASE_IMGTYPE_BGRA == imgType)
		{
			if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t v = *pEx;
						*((uint32_t*)pDestEx) = (v & 0x000000FF) | ((v << 8) & 0x0000FF00) | ((v << 16) & 0x00FF0000) | 0xFF000000;

						++pEx;
						pDestEx += 4;
					}
				}
			}
			else if (PNG_COLOR_TYPE_RGB == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 3;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t r = pEx[0];
						uint8_t g = pEx[1];
						uint8_t b = pEx[2];
						*((uint32_t*)pDestEx) = (b & 0x000000FF) | ((g << 8) & 0x0000FF00) | ((r << 16) & 0x00FF0000) | 0xFF000000;

						pEx += 3;
						pDestEx += 4;
					}
				}
			}
			else if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 2;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t v = pEx[0];
						uint8_t alpha = pEx[1];
						*((uint32_t*)pDestEx) = (v & 0x000000FF) | ((v << 8) & 0x0000FF00) | ((v << 16) & 0x00FF0000) | ((alpha << 24) & 0xFF000000);

						pEx += 2;
						pDestEx += 4;
					}
				}
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type);

				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 4;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;
					
					while (pEx < pExEnd)
					{
						pDestEx[0] = pEx[2];
						pDestEx[1] = pEx[1];
						pDestEx[2] = pEx[0];
						pDestEx[3] = pEx[3];

						pEx += 4;
						pDestEx += 4;
					}
				}
			}
		}
		else
		{
			assert(HGBASE_IMGTYPE_RGBA == imgType);

			if (PNG_COLOR_TYPE_GRAY == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t v = *pEx;
						*((uint32_t*)pDestEx) = (v & 0x000000FF) | ((v << 8) & 0x0000FF00) | ((v << 16) & 0x00FF0000) | 0xFF000000;

						++pEx;
						pDestEx += 4;
					}
				}
			}
			else if (PNG_COLOR_TYPE_RGB == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 3;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t r = pEx[0];
						uint8_t g = pEx[1];
						uint8_t b = pEx[2];
						*((uint32_t*)pDestEx) = (r & 0x000000FF) | ((g << 8) & 0x0000FF00) | ((b << 16) & 0x00FF0000) | 0xFF000000;

						pEx += 3;
						pDestEx += 4;
					}
				}
			}
			else if (PNG_COLOR_TYPE_GRAY_ALPHA == info_ptr->color_type)
			{
				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pExEnd = pEx + info_ptr->width * 2;
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;

					while (pEx < pExEnd)
					{
						uint8_t v = pEx[0];
						uint8_t alpha = pEx[1];
						*((uint32_t*)pDestEx) = (v & 0x000000FF) | ((v << 8) & 0x0000FF00) | ((v << 16) & 0x00FF0000) | ((alpha << 24) & 0xFF000000);

						pEx += 2;
						pDestEx += 4;
					}
				}
			}
			else
			{
				assert(PNG_COLOR_TYPE_RGB_ALPHA == info_ptr->color_type);

				//#pragma omp parallel for
				for (png_int_32 i = 0; i < (png_int_32)info_ptr->height; i++)
				{
					uint8_t* pEx = rowPointers[i];
					uint8_t* pDestEx = dest + (HGSize)i * (HGSize)destStep;
					memcpy(pDestEx, pEx, info_ptr->width * 4);
				}
			}
		}

		free(rowPointers);
		rowPointers = NULL;
		free(buffer);
		buffer = NULL;
		*image = image2;
	}

	png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
	fclose(file);
	file = NULL;
	return HGBASE_ERR_OK;
}

HGResult HGAPI HGImgFmt_SavePngImage(HGImage image, const HGPngSaveInfo* info, const HGChar* fileName)
{
	if (NULL == image || NULL == fileName)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	if (NULL != info)
	{
		// 判断合法性
	}

	HGImageInfo imgInfo;
	HGBase_GetImageInfo(image, &imgInfo);

	uint32_t width = imgInfo.width;
	uint32_t height = imgInfo.height;
	uint32_t widthStep = imgInfo.widthStep;
	uint32_t type = imgInfo.type;
	uint32_t origin = imgInfo.origin;

	if (HGBASE_IMGTYPE_GRAY != type && HGBASE_IMGTYPE_RGB != type
		&& HGBASE_IMGTYPE_RGBA != type)
	{
		return HGBASE_ERR_INVALIDARG;
	}

	FILE* file = fopen(fileName, "wb");
	if (NULL == file)
	{
		return HGBASE_ERR_ACCESSDENIED;
	}

	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
	if (NULL == png_ptr)
	{
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	png_infop info_ptr = png_create_info_struct(png_ptr);
	if (NULL == info_ptr)
	{
		png_destroy_write_struct(&png_ptr, NULL);
		fclose(file);
		file = NULL;
		return HGBASE_ERR_FAIL;
	}

	uint8_t** rowPointers = NULL;

	int jmpResult = setjmp(png_jmpbuf(png_ptr));
	if (0 != jmpResult)
	{
		free(rowPointers);
		rowPointers = NULL;
		png_destroy_write_struct(&png_ptr, &info_ptr);
		fclose(file);
		file = NULL;
		return (HGResult)jmpResult;
	}

	png_init_io(png_ptr, file);

	uint8_t* data;
	HGBase_GetImageData(image, &data);

	int color_type = -1;
	if (HGBASE_IMGTYPE_GRAY == type)
		color_type = PNG_COLOR_TYPE_GRAY;
	else if (HGBASE_IMGTYPE_RGB == type)
		color_type = PNG_COLOR_TYPE_RGB;
	else if (HGBASE_IMGTYPE_RGBA == type)
		color_type = PNG_COLOR_TYPE_RGB_ALPHA;
	assert(-1 != color_type);

	png_set_IHDR(png_ptr, info_ptr, width, height, 8, color_type, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);

	HGUInt xDpi, yDpi;
	HGBase_GetImageDpi(image, &xDpi, &yDpi);
	info_ptr->phys_unit_type = 1;
	info_ptr->x_pixels_per_unit = (uint32_t)((double)xDpi * 39.3700787 + 0.5);
	info_ptr->y_pixels_per_unit = (uint32_t)((double)yDpi * 39.3700787 + 0.5);
	info_ptr->valid |= PNG_INFO_pHYs;

	if (NULL != info)
	{
		info_ptr->phys_unit_type = info->physUnitType;
		info_ptr->x_pixels_per_unit = info->xPixelsPerUnit;
		info_ptr->y_pixels_per_unit = info->yPixelsPerUnit;
		info_ptr->valid |= PNG_INFO_pHYs;
	}

	png_write_info(png_ptr, info_ptr);

	rowPointers = (uint8_t**)malloc(height * sizeof(png_bytep));
	if (NULL == rowPointers)
	{
		longjmp(png_jmpbuf(png_ptr), (int)HGBASE_ERR_FAIL);
	}

	HGByte* p = data;
	HGSize step = (HGSize)widthStep;
	if (HGBASE_IMGORIGIN_BOTTOM == origin)
	{
		p = data + (HGUSize)(height - 1) * (HGUSize)widthStep;
		step = -(HGSize)widthStep;
	}

	//#pragma omp parallel for
	for (int32_t i = 0; i < (int32_t)height; ++i)
	{
		rowPointers[i] = p + (HGSize)i * (HGSize)step;
	}

	png_write_image(png_ptr, rowPointers);
	png_write_end(png_ptr, info_ptr);

	free(rowPointers);
	rowPointers = NULL;
	png_destroy_write_struct(&png_ptr, &info_ptr);
	fclose(file);
	file = NULL;
	return HGBASE_ERR_OK;
}