54 lines
1.9 KiB
C
54 lines
1.9 KiB
C
/* ************************************************************************** */
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/* */
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/* ML_filled_ellipse.c */
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/* | Project : monochromelib */
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/* */
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/* By: Pierre "PierrotLL" Le Gall <legallpierre89@gmail.com> */
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/* Last updated: 2011/11/22 */
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/* */
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/* ************************************************************************** */
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#include <monochrome/internals.h>
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void ML_filled_ellipse(int x, int y, int radius1, int radius2, ML_Color color)
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{
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int plot_x, plot_y;
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float d1, d2;
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if(radius1 < 1 || radius2 < 1) return;
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plot_x = 0;
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plot_y = radius2;
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d1 = radius2*radius2 - radius1*radius1*radius2 + radius1*radius1/4;
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while(radius1*radius1*(plot_y-.5) > radius2*radius2*(plot_x+1))
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{
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if(d1 < 0)
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{
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d1 += radius2*radius2*(2*plot_x+3);
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plot_x++;
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} else {
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d1 += radius2*radius2*(2*plot_x+3) + radius1*radius1*(-2*plot_y+2);
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ML_horizontal_line(y+plot_y, x-plot_x, x+plot_x, color);
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ML_horizontal_line(y-plot_y, x-plot_x, x+plot_x, color);
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plot_x++;
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plot_y--;
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}
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}
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ML_horizontal_line(y+plot_y, x-plot_x, x+plot_x, color);
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ML_horizontal_line(y-plot_y, x-plot_x, x+plot_x, color);
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d2 = radius2*radius2*(plot_x+.5)*(plot_x+.5) + radius1*radius1*(plot_y-1)*(plot_y-1) - radius1*radius1*radius2*radius2;
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while(plot_y > 0)
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{
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if(d2 < 0)
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{
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d2 += radius2*radius2*(2*plot_x+2) + radius1*radius1*(-2*plot_y+3);
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plot_y--;
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plot_x++;
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} else {
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d2 += radius1*radius1*(-2*plot_y+3);
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plot_y--;
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}
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ML_horizontal_line(y+plot_y, x-plot_x, x+plot_x, color);
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if(plot_y > 0)
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ML_horizontal_line(y-plot_y, x-plot_x, x+plot_x, color);
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}
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}
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