minetestmapper/Image.cpp

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#include <cstdio>
#include <cerrno>
#include <cstring>
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <gd.h>
#include <gdfontmb.h>
#include "Image.h"
#ifndef NDEBUG
#define SIZECHECK(x, y) check_bounds((x), (y), m_width, m_height)
#else
#define SIZECHECK(x, y) do {} while(0)
#endif
2016-11-18 23:57:09 +01:00
// ARGB but with inverted alpha
static inline int color2int(Color c)
{
u8 a = 255 - c.a;
return (a << 24) | (c.r << 16) | (c.g << 8) | c.b;
}
static inline Color int2color(int c)
{
Color c2;
u8 a;
c2.b = c & 0xff;
c2.g = (c >> 8) & 0xff;
c2.r = (c >> 16) & 0xff;
a = (c >> 24) & 0xff;
c2.a = 255 - a;
return c2;
}
static inline void check_bounds(int x, int y, int width, int height)
{
if(x < 0 || x >= width) {
std::ostringstream oss;
oss << "Access outside image bounds (x), 0 < "
<< x << " < " << width << " is false.";
throw std::out_of_range(oss.str());
}
if(y < 0 || y >= height) {
std::ostringstream oss;
oss << "Access outside image bounds (y), 0 < "
<< y << " < " << height << " is false.";
throw std::out_of_range(oss.str());
}
}
Image::Image(int width, int height) :
m_width(width), m_height(height), m_image(NULL)
{
m_image = gdImageCreateTrueColor(m_width, m_height);
}
Image::~Image()
{
gdImageDestroy(m_image);
}
void Image::setPixel(int x, int y, const Color &c)
{
SIZECHECK(x, y);
m_image->tpixels[y][x] = color2int(c);
}
Color Image::getPixel(int x, int y)
{
SIZECHECK(x, y);
return int2color(m_image->tpixels[y][x]);
}
void Image::drawLine(int x1, int y1, int x2, int y2, const Color &c)
{
SIZECHECK(x1, y1);
SIZECHECK(x2, y2);
gdImageLine(m_image, x1, y1, x2, y2, color2int(c));
}
void Image::drawText(int x, int y, const std::string &s, const Color &c)
{
SIZECHECK(x, y);
gdImageString(m_image, gdFontGetMediumBold(), x, y, (unsigned char*) s.c_str(), color2int(c));
}
void Image::drawFilledRect(int x, int y, int w, int h, const Color &c)
{
SIZECHECK(x, y);
SIZECHECK(x + w - 1, y + h - 1);
gdImageFilledRectangle(m_image, x, y, x + w - 1, y + h - 1, color2int(c));
}
void Image::drawCircle(int x, int y, int diameter, const Color &c)
{
SIZECHECK(x, y);
gdImageArc(m_image, x, y, diameter, diameter, 0, 360, color2int(c));
}
void Image::save(const std::string &filename)
{
FILE *f = fopen(filename.c_str(), "wb");
if(!f) {
std::ostringstream oss;
oss << "Error writing image file: " << std::strerror(errno);
throw std::runtime_error(oss.str());
}
gdImagePng(m_image, f); // other formats?
fclose(f);
}