dmlib: dmline.c annotate

annotate dmline.c @ 133:92cc5e1fa180

Some work on line drawing routines.

author	Matti Hamalainen <ccr@tnsp.org>
date	Fri, 05 Oct 2012 00:36:40 +0300
parents	997e26f17946
children	79dac918c81e

rev	line source
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	1 /*
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	2 * DMLib
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	3 * -- Arbitrary line drawing functions
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	4 * Programmed and designed by Matti 'ccr' Hamalainen
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	5 * (C) Copyright 2011 Tecnic Software productions (TNSP)
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	6 */
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	7 #include "dmlib.h"
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	8
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	9
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	10 /* Clip line coordinates. Return value:
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	11 * = 0 : No clipping needed.
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	12 * > 0 : Clipped. Line partially inside the clipping area.
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	13 * < 0 : Line completely outside the clipping area.
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	14 */
133 92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	15 #define dmClipBits(Q, x, y) \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	16 do { \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	17 Q = 0; \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	18 if (x < clipX0) Q \|= 1; \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	19 else \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	20 if (x > clipX1) Q \|= 2; \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	21 if (y < clipY0) Q \|= 4; \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	22 else \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	23 if (y > clipY1) Q \|= 8; \
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	24 } while (0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	25
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	26 #define xA (*x0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	27 #define xB (*x1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	28 #define yA (*y0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	29 #define yB (*y1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	30
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	31 int dmClipLineCoords(int x0, int y0, int x1, int y1, SDL_Surface *screen)
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	32 {
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	33 const int clipX0 = screen->clip_rect.x,
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	34 clipY0 = screen->clip_rect.y;
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	35 const int clipX1 = clipX0 + screen->clip_rect.w - 1,
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	36 clipY1 = clipY0 + screen->clip_rect.h - 1;
133 92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	37
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	38 int cA, cB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	39
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	40 dmClipBits(cA, xA, yA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	41 dmClipBits(cB, xB, yB);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	42
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	43 if (cA & cB)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	44 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	45
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	46 if ((cA \| cB) == 0) /* the line segment is inside of the clipping rectangle */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	47 return 0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	48
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	49 #if 1
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	50 // Cohen-Sutherland clipping method
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	51 do
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	52 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	53 const int c = cA ? cA : cB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	54 int x, y;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	55
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	56 if (c & 1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	57 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	58 y = yA + ((clipX0 - xA)*(yB - yA)) / (xB - xA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	59 x = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	60 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	61 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	62 if (c & 2)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	63 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	64 y = yA + ((clipX1 - xA)*(yB - yA)) / (xB - xA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	65 x = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	66 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	67 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	68 if (c & 4)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	69 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	70 x = xA + ((clipY0 - yA)*(xB - xA)) / (yB - yA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	71 y = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	72 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	73 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	74 if (c & 8)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	75 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	76 x = xA + ((clipY1 - yA)*(xB - xA)) / (yB - yA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	77 y = clipY1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	78 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	79
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	80 if (c == cA)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	81 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	82 xA = x;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	83 yA = y;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	84 dmClipBits(cA, xA, yA);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	85 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	86 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	87 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	88 xB = x;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	89 yB = y;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	90 dmClipBits(cB, xB, yB);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	91 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	92
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	93 } while (cA \| cB);
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	94 #else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	95 // Buyu-Skala clipping method
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	96 const int dx = xB - xA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	97 const int dy = yB - yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	98 float k, m;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	99 int z;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	100
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	101 switch (cA + cB)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	102 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	103 case 1:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	104 if (cA == 1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	105 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	106 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	107 yA = (clipX0 - xB) * dy / dx + yB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	108 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	109 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	110 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	111 xB = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	112 yB = (clipX0 - xA) * dy / dx + yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	113 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	114 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	115
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	116 case 3:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	117 k = dy / dx;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	118 yA = (clipX0 - xA) * k + yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	119 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	120 yB = (clipX1 - xB) * k + yB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	121 xB = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	122 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	123
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	124 case 5:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	125 k = dy / dx;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	126 z = (clipX0 - xA) * k + yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	127 if (z < clipY0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	128 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	129 switch (cA)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	130 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	131 case 0:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	132 xB = xB + (clipY0 - yB) / k;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	133 yB = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	134 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	135 case 5:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	136 xA = xA + (clipY0 - yA) / k;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	137 yA = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	138 break;
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	139
133 92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	140 default:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	141 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	142 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	143 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	144 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	145 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	146 switch (cA)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	147 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	148 case 0:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	149 xB = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	150 yB = z;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	151 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	152 case 1:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	153 xB = xB + (clipY0 - yB) / k;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	154 yB = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	155 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	156 yA = z;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	157 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	158 case 4:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	159 xA = xA + (clipY0 - yA) / k;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	160 yA = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	161 xB = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	162 yB = z;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	163 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	164 case 5:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	165 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	166 yA = z;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	167 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	168 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	169 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	170 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	171
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	172 case 7:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	173 switch (cA)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	174 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	175 case 1:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	176 k = dy / dx;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	177 yA = (clipX0 - xB) * k + yB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	178 if (yA < clipY0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	179 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	180 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	181 yB = (clipX1 - clipX0) * k + yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	182 if (yB < clipY0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	183 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	184 xB = (clipY0 - yB) / k + clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	185 yB = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	186 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	187 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	188 xB = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	189 break;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	190
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	191 /* similarly for cases cA == 2, 5, 6 */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	192 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	193 case 15:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	194 switch (cA)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	195 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	196 case 5:
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	197 if (dy * (clipX1 - clipX0) < dx * (clipY1 - clipY0))
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	198 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	199 k = dy / dx;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	200 yA = (clipX0 - xB) * k + yB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	201 if (yA > clipY1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	202 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	203 yB = (clipX1 - clipX0) * k + yA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	204 if (yB < clipY0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	205 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	206 if (yA < clipY0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	207 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	208 xA = (clipY0 - yA) / k + clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	209 yA = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	210 xB = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	211 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	212 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	213 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	214 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	215 if (yB > clipY1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	216 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	217 xB = (clipY1 - yB) / k + clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	218 yB = clipY1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	219 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	220 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	221 xB = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	222 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	223 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	224 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	225 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	226 m = dx / dy;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	227 xA = (clipY0 - yB) * m + xB;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	228 if (xA > clipX1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	229 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	230 xB = (clipY1 - clipY0) * m + xA;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	231 if (xB < clipX0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	232 return -1; /* the line segment is outside */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	233 if (xA < clipX0)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	234 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	235 yA = (clipX0 - xA) / m + clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	236 xA = clipX0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	237 yB = clipY1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	238 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	239 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	240 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	241 yA = clipY0;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	242 if (xB > clipX1)
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	243 {
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	244 yB = (clipX1 - xB) / m + clipY1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	245 xB = clipX1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	246 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	247 else
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	248 yB = clipY1;
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	249 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	250 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	251
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	252 /* similarly for cases cA == 6, 9, 10 */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	253 }
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	254
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	255 /* cases 2, 4, 8 are similar as case 1, cases 6, 9, 10 are similar as case 5 */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	256 /* cases 11, 13, 14 are similar as case 7, case 12 is similar case 3 */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	257 } /* of case cA + cB */
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	258 #endif
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	259
92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	260 return 1;
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	261 }
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	262
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	263
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	264
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	265 #include "dmlinefunc.h"
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	266
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	267 static const DMDrawLineFunc dmDrawLineTable[DMD_NMODES][DMD_NBITDEPTHS] =
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	268 {
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	269 /* DMD_NONE */ { dmDrawLine8 , dmDrawLine32 },
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	270 /* DMD_TRANSPARENT */ { dmDrawLine8Transparent , dmDrawLine32Transparent },
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	271 /* DMD_SATURATE */ { dmDrawLine8Saturate , dmDrawLine32Saturate },
133 92cc5e1fa180 Some work on line drawing routines. Matti Hamalainen <ccr@tnsp.org> parents: 22 diff changeset	272 #if 0
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	273 /* DMD_NONE + AA */ { NULL, NULL },
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	274 /* DMD_TRANSP + AA */ { NULL, NULL },
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	275 /* DMD_SATURATE + AA */ { dmDrawLine8AASaturate , dmDrawLine32AASaturate },
22 997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	276 #endif
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	277 };
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	278
22 997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	279 static const int ndmDrawLineTable = sizeof(dmDrawLineTable) / sizeof(dmDrawLineTable[0]);
997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	280
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	281
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	282 DMDrawLineFunc dmGetDrawLineFunc(SDL_PixelFormat *dst, int mode)
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	283 {
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	284 int index;
22 997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	285 if (dst == NULL \|\| mode < 0 \|\| mode >= ndmDrawLineTable)
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	286 return NULL;
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	287
22 997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	288 if ((index = dmBitsPerPixel2Index(dst->BitsPerPixel)) < 0)
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	289 return NULL;
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	290
22 997e26f17946 Initial fixes for getting the line drawing functions "working". Matti Hamalainen <ccr@tnsp.org> parents: 0 diff changeset	291 return dmDrawLineTable[mode][index];
0 32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	292 }
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	293
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	294
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	295 int dmDrawLineAny(SDL_Surface *screen, int x0, int y0, int x1, int y1, const Uint32 col, int mode)
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	296 {
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	297 DMDrawLineFunc bfunc = dmGetDrawLineFunc(screen->format, mode);
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	298
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	299 if (bfunc == NULL)
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	300 return -15;
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	301
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	302 return bfunc(screen, x0, y0, x1, y1, col);
32250b436bca Initial re-import. Matti Hamalainen <ccr@tnsp.org> parents: diff changeset	303 }

Mercurial > hg > dmlib

annotate dmline.c @ 133:92cc5e1fa180