litehtml/containers/test/Bitmap.cpp
2024-05-16 22:54:49 +03:00

133 lines
3.3 KiB
C++

#include "Bitmap.h"
#include "lodepng.h"
#include "canvas_ity.hpp"
using namespace canvas_ity;
Bitmap::Bitmap(canvas& canvas) : Bitmap(canvas.width(), canvas.height())
{
canvas.get_image_data((byte*)data.data(), width, height, width * 4, 0, 0);
}
color Bitmap::get_pixel(int x, int y) const
{
if (x < 0 || x >= width || y < 0 || y >= height)
return black;
else
return data[x + y * width];
}
void Bitmap::set_pixel(int x, int y, color color)
{
if (x < 0 || x >= width || y < 0 || y >= height) return;
if (color.a == 0) return;
data[x + y * width] = color;
}
// endpoint is not drawn, like in GDI
void Bitmap::draw_line(int x0, int y0, int x1, int y1, color color)
{
if (x0 != x1 && y0 != y1) return; // only horz and vert lines supported
if (x0 == x1) // vert line
{
if (y0 > y1) swap(y0, y1);
for (int y = y0; y < y1; y++)
set_pixel(x0, y, color);
}
else if (y0 == y1) // horz line
{
if (x0 > x1) swap(x0, x1);
for (int x = x0; x < x1; x++)
set_pixel(x, y0, color);
}
}
void Bitmap::draw_rect(int x, int y, int _width, int _height, color color)
{
draw_line(x, y, x + _width, y, color); // top
draw_line(x, y + _height - 1, x + _width, y + _height - 1, color); // bottom
draw_line(x, y, x, y + _height, color); // left
draw_line(x + _width - 1, y, x + _width - 1, y + _height, color); // right
}
void Bitmap::fill_rect(rect rect, color color)
{
for (int y = rect.top(); y < rect.bottom(); y++)
for (int x = rect.left(); x < rect.right(); x++)
set_pixel(x, y, color);
}
void Bitmap::replace_color(color original, color replacement)
{
for (auto& pixel : data)
{
if (pixel == original)
pixel = replacement;
}
}
// find minimal rectangle containing pixels different from bgcolor
rect Bitmap::find_picture(color bgcolor)
{
auto horz_line_empty = [&](int y) {
for (int x = 0; x < width; x++)
if (data[x + y * width] != bgcolor) return false;
return true;
};
auto vert_line_empty = [&](int x) {
for (int y = 0; y < height; y++)
if (data[x + y * width] != bgcolor) return false;
return true;
};
rect rect;
int y;
for (y = 0; y < height && horz_line_empty(y); y++);
if (y == height) return rect; // no picture
rect.y = y;
for (y = height - 1; y >= 0 && horz_line_empty(y); y--);
rect.height = y + 1 - rect.y;
int x;
for (x = 0; x < width && vert_line_empty(x); x++);
rect.x = x;
for (x = width - 1; x >= 0 && vert_line_empty(x); x--);
rect.width = x + 1 - rect.x;
return rect;
}
void Bitmap::load(string filename)
{
vector<byte> image;
unsigned w, h;
lodepng::decode(image, w, h, filename);
if (w * h == 0) return;
width = w;
height = h;
data.resize(w * h);
memcpy(data.data(), image.data(), w * h * 4);
}
void Bitmap::save(string filename)
{
lodepng::encode(filename, (byte*)data.data(), width, height);
}
// This function can be used to compare gradient rendering between different browsers.
byte max_color_diff(const Bitmap& a, const Bitmap& b)
{
if (a.width != b.width || a.height != b.height)
return 255;
int diff = 0;
for (int y = 0; y < a.height; y++)
for (int x = 0; x < a.width; x++)
{
color A = a.get_pixel(x, y);
color B = b.get_pixel(x, y);
diff = max({diff, abs(A.r - B.r), abs(A.g - B.g), abs(A.b - B.b), abs(A.a - B.a)});
}
return (byte)diff;
}