dmlib: dmlineclip.h annotate

annotate dmlineclip.h @ 234:a2abd0b991b6

Modularize line drawing related templates and functions, add clipping functions to dmlib.h.

author	Matti Hamalainen <ccr@tnsp.org>
date	Mon, 08 Oct 2012 15:21:59 +0300
parents	79dac918c81e
children	9d015d32841a

rev	line source
232 79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	1
234 a2abd0b991b6 Modularize line drawing related templates and functions, add clipping Matti Hamalainen <ccr@tnsp.org> parents: 232 diff changeset	2 int DM_CLIP_FUNC (SDL_Surface screen, DM_COORD_TYPE x0, DM_COORD_TYPE y0, DM_COORD_TYPE x1, DM_COORD_TYPE *y1)
a2abd0b991b6 Modularize line drawing related templates and functions, add clipping Matti Hamalainen <ccr@tnsp.org> parents: 232 diff changeset	3 #ifdef DM_HEADER
a2abd0b991b6 Modularize line drawing related templates and functions, add clipping Matti Hamalainen <ccr@tnsp.org> parents: 232 diff changeset	4 ;
a2abd0b991b6 Modularize line drawing related templates and functions, add clipping Matti Hamalainen <ccr@tnsp.org> parents: 232 diff changeset	5 #else
232 79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	6 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	7 const DM_COORD_TYPE
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	8 clipX0 = screen->clip_rect.x,
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	9 clipY0 = screen->clip_rect.y,
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	10 clipX1 = clipX0 + screen->clip_rect.w - 1,
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	11 clipY1 = clipY0 + screen->clip_rect.h - 1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	12
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	13 int cA, cB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	14
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	15 dmClipBits(cA, xA, yA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	16 dmClipBits(cB, xB, yB);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	17
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	18 if (cA & cB)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	19 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	20
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	21 if ((cA \| cB) == 0) /* the line segment is inside of the clipping rectangle */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	22 return 0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	23
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	24 #if 1
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	25 // Cohen-Sutherland clipping method
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	26 do
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	27 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	28 const int c = cA ? cA : cB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	29 DM_COORD_TYPE x, y;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	30
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	31 if (c & 1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	32 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	33 y = yA + ((clipX0 - xA)*(yB - yA)) / (xB - xA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	34 x = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	35 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	36 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	37 if (c & 2)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	38 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	39 y = yA + ((clipX1 - xA)*(yB - yA)) / (xB - xA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	40 x = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	41 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	42 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	43 if (c & 4)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	44 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	45 x = xA + ((clipY0 - yA)*(xB - xA)) / (yB - yA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	46 y = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	47 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	48 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	49 if (c & 8)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	50 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	51 x = xA + ((clipY1 - yA)*(xB - xA)) / (yB - yA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	52 y = clipY1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	53 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	54
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	55 if (c == cA)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	56 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	57 xA = x;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	58 yA = y;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	59 dmClipBits(cA, xA, yA);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	60 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	61 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	62 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	63 xB = x;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	64 yB = y;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	65 dmClipBits(cB, xB, yB);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	66 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	67
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	68 } while (cA \| cB);
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	69 #else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	70 // Buyu-Skala clipping method
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	71 const DM_COORD_TYPE dx = xB - xA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	72 const DM_COORD_TYPE dy = yB - yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	73 float k, m;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	74 int z;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	75
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	76 switch (cA + cB)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	77 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	78 case 1:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	79 if (cA == 1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	80 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	81 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	82 yA = (clipX0 - xB) * dy / dx + yB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	83 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	84 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	85 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	86 xB = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	87 yB = (clipX0 - xA) * dy / dx + yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	88 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	89 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	90
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	91 case 3:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	92 k = dy / dx;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	93 yA = (clipX0 - xA) * k + yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	94 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	95 yB = (clipX1 - xB) * k + yB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	96 xB = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	97 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	98
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	99 case 5:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	100 k = dy / dx;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	101 z = (clipX0 - xA) * k + yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	102 if (z < clipY0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	103 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	104 switch (cA)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	105 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	106 case 0:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	107 xB = xB + (clipY0 - yB) / k;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	108 yB = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	109 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	110 case 5:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	111 xA = xA + (clipY0 - yA) / k;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	112 yA = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	113 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	114
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	115 default:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	116 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	117 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	118 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	119 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	120 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	121 switch (cA)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	122 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	123 case 0:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	124 xB = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	125 yB = z;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	126 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	127 case 1:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	128 xB = xB + (clipY0 - yB) / k;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	129 yB = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	130 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	131 yA = z;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	132 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	133 case 4:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	134 xA = xA + (clipY0 - yA) / k;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	135 yA = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	136 xB = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	137 yB = z;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	138 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	139 case 5:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	140 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	141 yA = z;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	142 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	143 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	144 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	145 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	146
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	147 case 7:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	148 switch (cA)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	149 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	150 case 1:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	151 k = dy / dx;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	152 yA = (clipX0 - xB) * k + yB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	153 if (yA < clipY0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	154 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	155 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	156 yB = (clipX1 - clipX0) * k + yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	157 if (yB < clipY0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	158 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	159 xB = (clipY0 - yB) / k + clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	160 yB = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	161 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	162 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	163 xB = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	164 break;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	165
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	166 /* similarly for cases cA == 2, 5, 6 */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	167 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	168 case 15:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	169 switch (cA)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	170 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	171 case 5:
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	172 if (dy * (clipX1 - clipX0) < dx * (clipY1 - clipY0))
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	173 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	174 k = dy / dx;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	175 yA = (clipX0 - xB) * k + yB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	176 if (yA > clipY1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	177 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	178 yB = (clipX1 - clipX0) * k + yA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	179 if (yB < clipY0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	180 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	181 if (yA < clipY0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	182 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	183 xA = (clipY0 - yA) / k + clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	184 yA = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	185 xB = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	186 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	187 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	188 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	189 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	190 if (yB > clipY1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	191 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	192 xB = (clipY1 - yB) / k + clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	193 yB = clipY1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	194 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	195 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	196 xB = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	197 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	198 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	199 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	200 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	201 m = dx / dy;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	202 xA = (clipY0 - yB) * m + xB;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	203 if (xA > clipX1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	204 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	205 xB = (clipY1 - clipY0) * m + xA;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	206 if (xB < clipX0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	207 return -1; /* the line segment is outside */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	208 if (xA < clipX0)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	209 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	210 yA = (clipX0 - xA) / m + clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	211 xA = clipX0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	212 yB = clipY1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	213 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	214 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	215 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	216 yA = clipY0;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	217 if (xB > clipX1)
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	218 {
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	219 yB = (clipX1 - xB) / m + clipY1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	220 xB = clipX1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	221 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	222 else
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	223 yB = clipY1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	224 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	225 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	226
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	227 /* similarly for cases cA == 6, 9, 10 */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	228 }
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	229
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	230 /* cases 2, 4, 8 are similar as case 1, cases 6, 9, 10 are similar as case 5 */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	231 /* cases 11, 13, 14 are similar as case 7, case 12 is similar case 3 */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	232 } /* of case cA + cB */
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	233 #endif
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	234
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	235 return 1;
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	236 }
234 a2abd0b991b6 Modularize line drawing related templates and functions, add clipping Matti Hamalainen <ccr@tnsp.org> parents: 232 diff changeset	237 #endif
232 79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	238
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	239 #undef DM_CLIP_FUNC
79dac918c81e Modularize line clipping etc. a lot, and export all line drawing and Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	240 #undef DM_COORD_TYPE

Mercurial > hg > dmlib

annotate dmlineclip.h @ 234:a2abd0b991b6