SFML/src/SFML/Graphics/ImageLoader.cpp

323 lines
9.5 KiB
C++

////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2014 Laurent Gomila (laurent.gom@gmail.com)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
// you must not claim that you wrote the original software.
// If you use this software in a product, an acknowledgment
// in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
// and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Graphics/ImageLoader.hpp>
#include <SFML/System/InputStream.hpp>
#include <SFML/System/Err.hpp>
#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include <stb_image_write.h>
extern "C"
{
#include <jpeglib.h>
#include <jerror.h>
}
#include <cctype>
namespace
{
// Convert a string to lower case
std::string toLower(std::string str)
{
for (std::string::iterator i = str.begin(); i != str.end(); ++i)
*i = static_cast<char>(std::tolower(*i));
return str;
}
// stb_image callbacks that operate on a sf::InputStream
int read(void* user, char* data, int size)
{
sf::InputStream* stream = static_cast<sf::InputStream*>(user);
return static_cast<int>(stream->read(data, size));
}
void skip(void* user, int size)
{
sf::InputStream* stream = static_cast<sf::InputStream*>(user);
stream->seek(stream->tell() + size);
}
int eof(void* user)
{
sf::InputStream* stream = static_cast<sf::InputStream*>(user);
return stream->tell() >= stream->getSize();
}
}
namespace sf
{
namespace priv
{
////////////////////////////////////////////////////////////
ImageLoader& ImageLoader::getInstance()
{
static ImageLoader Instance;
return Instance;
}
////////////////////////////////////////////////////////////
ImageLoader::ImageLoader()
{
// Nothing to do
}
////////////////////////////////////////////////////////////
ImageLoader::~ImageLoader()
{
// Nothing to do
}
////////////////////////////////////////////////////////////
bool ImageLoader::loadImageFromFile(const std::string& filename, std::vector<Uint8>& pixels, Vector2u& size)
{
// Clear the array (just in case)
pixels.clear();
// Load the image and get a pointer to the pixels in memory
int width, height, channels;
unsigned char* ptr = stbi_load(filename.c_str(), &width, &height, &channels, STBI_rgb_alpha);
if (ptr && width && height)
{
// Assign the image properties
size.x = width;
size.y = height;
// Copy the loaded pixels to the pixel buffer
pixels.resize(width * height * 4);
memcpy(&pixels[0], ptr, pixels.size());
// Free the loaded pixels (they are now in our own pixel buffer)
stbi_image_free(ptr);
return true;
}
else
{
// Error, failed to load the image
err() << "Failed to load image \"" << filename << "\". Reason: " << stbi_failure_reason() << std::endl;
return false;
}
}
////////////////////////////////////////////////////////////
bool ImageLoader::loadImageFromMemory(const void* data, std::size_t dataSize, std::vector<Uint8>& pixels, Vector2u& size)
{
// Check input parameters
if (data && dataSize)
{
// Clear the array (just in case)
pixels.clear();
// Load the image and get a pointer to the pixels in memory
int width, height, channels;
const unsigned char* buffer = static_cast<const unsigned char*>(data);
unsigned char* ptr = stbi_load_from_memory(buffer, static_cast<int>(dataSize), &width, &height, &channels, STBI_rgb_alpha);
if (ptr && width && height)
{
// Assign the image properties
size.x = width;
size.y = height;
// Copy the loaded pixels to the pixel buffer
pixels.resize(width * height * 4);
memcpy(&pixels[0], ptr, pixels.size());
// Free the loaded pixels (they are now in our own pixel buffer)
stbi_image_free(ptr);
return true;
}
else
{
// Error, failed to load the image
err() << "Failed to load image from memory. Reason: " << stbi_failure_reason() << std::endl;
return false;
}
}
else
{
err() << "Failed to load image from memory, no data provided" << std::endl;
return false;
}
}
////////////////////////////////////////////////////////////
bool ImageLoader::loadImageFromStream(InputStream& stream, std::vector<Uint8>& pixels, Vector2u& size)
{
// Clear the array (just in case)
pixels.clear();
// Make sure that the stream's reading position is at the beginning
stream.seek(0);
// Setup the stb_image callbacks
stbi_io_callbacks callbacks;
callbacks.read = &read;
callbacks.skip = &skip;
callbacks.eof = &eof;
// Load the image and get a pointer to the pixels in memory
int width, height, channels;
unsigned char* ptr = stbi_load_from_callbacks(&callbacks, &stream, &width, &height, &channels, STBI_rgb_alpha);
if (ptr && width && height)
{
// Assign the image properties
size.x = width;
size.y = height;
// Copy the loaded pixels to the pixel buffer
pixels.resize(width * height * 4);
memcpy(&pixels[0], ptr, pixels.size());
// Free the loaded pixels (they are now in our own pixel buffer)
stbi_image_free(ptr);
return true;
}
else
{
// Error, failed to load the image
err() << "Failed to load image from stream. Reason: " << stbi_failure_reason() << std::endl;
return false;
}
}
////////////////////////////////////////////////////////////
bool ImageLoader::saveImageToFile(const std::string& filename, const std::vector<Uint8>& pixels, const Vector2u& size)
{
// Make sure the image is not empty
if (!pixels.empty() && (size.x > 0) && (size.y > 0))
{
// Deduce the image type from its extension
if (filename.size() > 3)
{
// Extract the extension
std::string extension = toLower(filename.substr(filename.size() - 3));
if (extension == "bmp")
{
// BMP format
if (stbi_write_bmp(filename.c_str(), size.x, size.y, 4, &pixels[0]))
return true;
}
else if (extension == "tga")
{
// TGA format
if (stbi_write_tga(filename.c_str(), size.x, size.y, 4, &pixels[0]))
return true;
}
else if (extension == "png")
{
// PNG format
if (stbi_write_png(filename.c_str(), size.x, size.y, 4, &pixels[0], 0))
return true;
}
else if (extension == "jpg")
{
// JPG format
if (writeJpg(filename, pixels, size.x, size.y))
return true;
}
}
}
err() << "Failed to save image \"" << filename << "\"" << std::endl;
return false;
}
////////////////////////////////////////////////////////////
bool ImageLoader::writeJpg(const std::string& filename, const std::vector<Uint8>& pixels, unsigned int width, unsigned int height)
{
// Open the file to write in
FILE* file = fopen(filename.c_str(), "wb");
if (!file)
return false;
// Initialize the error handler
jpeg_compress_struct compressInfos;
jpeg_error_mgr errorManager;
compressInfos.err = jpeg_std_error(&errorManager);
// Initialize all the writing and compression infos
jpeg_create_compress(&compressInfos);
compressInfos.image_width = width;
compressInfos.image_height = height;
compressInfos.input_components = 3;
compressInfos.in_color_space = JCS_RGB;
jpeg_stdio_dest(&compressInfos, file);
jpeg_set_defaults(&compressInfos);
jpeg_set_quality(&compressInfos, 90, TRUE);
// Get rid of the alpha channel
std::vector<Uint8> buffer(width * height * 3);
for (std::size_t i = 0; i < width * height; ++i)
{
buffer[i * 3 + 0] = pixels[i * 4 + 0];
buffer[i * 3 + 1] = pixels[i * 4 + 1];
buffer[i * 3 + 2] = pixels[i * 4 + 2];
}
Uint8* ptr = &buffer[0];
// Start compression
jpeg_start_compress(&compressInfos, TRUE);
// Write each row of the image
while (compressInfos.next_scanline < compressInfos.image_height)
{
JSAMPROW rawPointer = ptr + (compressInfos.next_scanline * width * 3);
jpeg_write_scanlines(&compressInfos, &rawPointer, 1);
}
// Finish compression
jpeg_finish_compress(&compressInfos);
jpeg_destroy_compress(&compressInfos);
// Close the file
fclose(file);
return true;
}
} // namespace priv
} // namespace sf