完成bresenham's line
parent
22984c1c87
commit
9b753769b1
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@ -3,9 +3,48 @@
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const TGAColor white = TGAColor(255, 255, 255, 255);
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const TGAColor red = TGAColor(255, 0, 0, 255);
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void line(int x0, int y0, int x1, int y1, TGAImage& image, TGAColor color) {
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bool steep = false;
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if (std::abs(x0-x1) < std::abs(y0-y1)) // 交换次序
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{
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std::swap(x0, y0);
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std::swap(x1, y1);
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steep = true;
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}
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if (x0 > x1)
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{
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std::swap(x0, x1);
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std::swap(y0, y1);
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}
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int dx = x1 - x0;
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int dy = y1 - y0;
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int derror2 = std::abs(dy) * 2;
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int error2 = 0;
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int y = y0;
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for (int x = x0; x <=x1; x++)
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{
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if (steep)
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{
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image.set(x, y, color);
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}
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else
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{
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image.set(x, y, color);
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}
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error2 += derror2;
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if (error2 > dx) // 误差值,提供从当前位置到最佳直线的距离
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{
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y += (y1 > y0 ? 1 : -1);
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error2 -= dx * 2;
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}
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}
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}
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int main(int argc, char** argv) {
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TGAImage image(100, 100, TGAImage::RGB);
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image.set(52, 41, red);
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line(52, 41,90,70,image ,red);
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image.flip_vertically(); // i want to have the origin at the left bottom corner of the image
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image.write_tga_file("output.tga");
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return 0;
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