Felisp
84436a5ae0
http://my.svgalib.org/svgalib/svgalib-1.9.25.tar.gz http://my.svgalib.org/svgalib/
546 lines
12 KiB
C
546 lines
12 KiB
C
/* Framebuffer Graphics Libary for Linux, Copyright 1993 Harm Hanemaayer */
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/* line.c Line drawing */
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#include <stdlib.h>
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#ifndef DO_NOT_USE_VGALIB
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#include <vga.h>
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#endif
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#include "inlstring.h" /* include inline string operations */
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#include "vgagl.h"
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#include "def.h"
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#include "driver.h"
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static inline int muldiv64(int m1, int m2, int d)
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{
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return (float) m1 * (float) m2 / ((float) d);
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}
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#ifdef NO_ASSEMBLY
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static inline int gl_regioncode (int x, int y)
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{
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int result = 0;
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if (x < __clipx1)
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result |= 1;
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else if (x > __clipx2)
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result |= 2;
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if (y < __clipy1)
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result |= 4;
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else if (y > __clipy2)
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result |= 8;
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return result;
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}
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#else
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#define INC_IF_NEG(y, result) \
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{ \
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__asm__("btl $31,%1\n\t" \
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"adcl $0,%0" \
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: "=r" ((int) result) \
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: "rm" ((int) (y)), "0" ((int) result) \
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); \
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}
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static inline int gl_regioncode (int x, int y)
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{
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int dx1, dx2, dy1, dy2;
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int result;
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result = 0;
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dy2 = __clipy2 - y;
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INC_IF_NEG (dy2, result);
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result <<= 1;
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dy1 = y - __clipy1;
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INC_IF_NEG (dy1, result);
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result <<= 1;
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dx2 = __clipx2 - x;
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INC_IF_NEG (dx2, result);
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result <<= 1;
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dx1 = x - __clipx1;
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INC_IF_NEG (dx1, result);
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return result;
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}
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#endif /* ! NO_ASSEMBLY */
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#define line_start_paged(s) \
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fp = y * bytesperrow + x * s; \
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vga_setpage (fpp = (fp >> 16)); \
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fp &= 0xFFFF;
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#define line_start_linear(s) \
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vp = (unsigned char *)VBUF + y * bytesperrow + x * s;
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#define line_loop_paged_a(m,i,u,v) \
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{ \
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int d = ay - (ax >> 1); \
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if ((x = abs (dx))) \
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do { \
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i; \
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if (d m 0) { \
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fp v; \
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d -= ax; \
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} \
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fp u; \
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d += ay; \
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if (fp & 0xFFFF0000) { /* has it cross a page boundary ? */ \
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fpp += fp >> 16; \
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vga_setpage (fpp); \
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} \
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fp &= 0x0000FFFF; \
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} while (--x); \
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}
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#define line_loop_linear_a(m,i,u,v) \
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{ \
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int d = ay - (ax >> 1); \
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if ((x = abs (dx))) \
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do { \
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i; \
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if (d m 0) { \
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vp v; \
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d -= ax; \
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} \
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vp u; \
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d += ay; \
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} while (--x); \
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}
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#define line_loop_paged_b(m,i,u,v) \
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{ \
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int d = ax - (ay >> 1); \
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if ((y = abs (dy))) \
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do { \
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i; \
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if (d m 0) { \
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fp u; \
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d -= ay; \
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} \
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fp v; \
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d += ax; \
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if (fp & 0xFFFF0000) { \
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fpp += fp >> 16; \
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vga_setpage (fpp); \
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} \
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fp &= 0x0000FFFF; \
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} while (--y); \
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}
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#define line_loop_linear_b(m,i,u,v) \
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{ \
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int d = ax - (ay >> 1); \
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if ((y = abs (dy))) \
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do { \
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i; \
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if (d m 0) { \
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vp u; \
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d -= ay; \
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} \
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vp v; \
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d += ax; \
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} while (--y); \
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}
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/* Partly based on the work which was partly based on vgalib by Tommy Frandsen */
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/* This is a lot faster now that setpixel is inlined */
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void gl_line (int x1, int y1, int x2, int y2, int c)
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{
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int dx, dy, ax, ay, sx, sy, x, y;
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int bytesperrow;
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unsigned char *vp = NULL;
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if (__clip)
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/* Cohen & Sutherland algorithm */
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for (;;) {
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int r1 = gl_regioncode (x1, y1);
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int r2 = gl_regioncode (x2, y2);
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if (!(r1 | r2))
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break; /* completely inside */
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if (r1 & r2)
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return; /* completely outside */
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if (r1 == 0) {
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swap (x1, x2); /* make sure first */
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swap (y1, y2); /* point is outside */
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r1 = r2;
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}
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if (r1 & 1) { /* left */
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y1 += muldiv64 (__clipx1 - x1, y2 - y1, x2 - x1);
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x1 = __clipx1;
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} else if (r1 & 2) { /* right */
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y1 += muldiv64 (__clipx2 - x1, y2 - y1, x2 - x1);
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x1 = __clipx2;
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} else if (r1 & 4) { /* top */
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x1 += muldiv64 (__clipy1 - y1, x2 - x1, y2 - y1);
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y1 = __clipy1;
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} else if (r1 & 8) { /* bottom */
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x1 += muldiv64 (__clipy2 - y1, x2 - x1, y2 - y1);
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y1 = __clipy2;
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}
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}
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dx = x2 - x1;
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dy = y2 - y1;
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ax = abs (dx) << 1;
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ay = abs (dy) << 1;
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sx = (dx >= 0) ? 1 : -1;
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sy = (dy >= 0) ? 1 : -1;
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x = x1;
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y = y1;
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#define insert_pixel_1 *((unsigned char *) vp) = c;
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#define insert_pixel_2 *((unsigned short *) vp) = c;
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#define insert_pixel_3 *((unsigned char *) vp) = c; \
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*((unsigned char *) (vp + 1)) = (c>>8); \
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*((unsigned char *) (vp + 2)) = (c>>16);
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#define insert_pixel_4 *((unsigned int *) vp) = c;
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bytesperrow = BYTEWIDTH;
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if (MODETYPE == CONTEXT_VIRTUAL || MODETYPE == CONTEXT_LINEAR) {
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switch BYTESPERPIXEL {
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case 1:
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line_start_linear(1);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_linear_a(>=,insert_pixel_1,++,+=bytesperrow*sy);
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} else {
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line_loop_linear_a(>,insert_pixel_1,--,+=bytesperrow*sy);
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}
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} else {
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if(sy > 0) {
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line_loop_linear_b(>=,insert_pixel_1,+=sx,+=bytesperrow);
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} else {
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line_loop_linear_b(>,insert_pixel_1,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_1;
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break;
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case 2:
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line_start_linear(2);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_linear_a(>=,insert_pixel_2,+=2,+=bytesperrow*sy);
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} else {
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line_loop_linear_a(>,insert_pixel_2,-=2,+=bytesperrow*sy);
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}
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} else {
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sx <<= 1;
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if(sy > 0) {
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line_loop_linear_b(>=,insert_pixel_2,+=sx,+=bytesperrow);
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} else {
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line_loop_linear_b(>,insert_pixel_2,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_2;
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break;
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case 3:
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line_start_linear(3);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_linear_a(>=,insert_pixel_3,+=3,+=bytesperrow*sy);
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} else {
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line_loop_linear_a(>,insert_pixel_3,-=3,+=bytesperrow*sy);
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}
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} else {
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sx *= 3;
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if(sy > 0) {
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line_loop_linear_b(>=,insert_pixel_3,+=sx,+=bytesperrow);
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} else {
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line_loop_linear_b(>,insert_pixel_3,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_3;
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break;
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case 4:
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line_start_linear(4);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_linear_a(>=,insert_pixel_4,+=4,+=bytesperrow*sy);
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} else {
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line_loop_linear_a(>,insert_pixel_4,-=4,+=bytesperrow*sy);
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}
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} else {
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sx <<= 2;
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if(sy > 0) {
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line_loop_linear_b(>=,insert_pixel_4,+=sx,+=bytesperrow);
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} else {
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line_loop_linear_b(>,insert_pixel_4,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_4;
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break;
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}
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}
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#ifndef DO_NOT_USE_VGALIB
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#undef insert_pixel_1
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#undef insert_pixel_2
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#undef insert_pixel_3
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#undef insert_pixel_4
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#define insert_pixel_1 *((unsigned char *) (vp + fp)) = c;
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#define insert_pixel_2 *((unsigned short *) (vp + fp)) = c;
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#define insert_pixel_3 *((unsigned char *) (vp + fp)) = c; \
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*((unsigned char *) (vp + fp + 1)) = (c>>8); \
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*((unsigned char *) (vp + fp + 2)) = (c>>16);
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#define insert_pixel_4 *((unsigned int *) (vp + fp)) = c;
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if (MODETYPE == CONTEXT_PAGED) {
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vp = (unsigned char *)VBUF;
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switch BYTESPERPIXEL {
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int fpp;
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int fp;
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case 1:
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line_start_paged(1);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_paged_a(>=,insert_pixel_1,++,+=bytesperrow*sy);
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} else {
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line_loop_paged_a(>,insert_pixel_1,--,+=bytesperrow*sy);
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}
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} else {
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if(sy > 0) {
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line_loop_paged_b(>=,insert_pixel_1,+=sx,+=bytesperrow);
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} else {
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line_loop_paged_b(>,insert_pixel_1,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_1;
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break;
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case 2:
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line_start_paged(2);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_paged_a(>=,insert_pixel_2,+=2,+=bytesperrow*sy);
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} else {
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line_loop_paged_a(>,insert_pixel_2,-=2,+=bytesperrow*sy);
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}
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} else {
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sx <<= 1;
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if(sy > 0) {
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line_loop_paged_b(>=,insert_pixel_2,+=sx,+=bytesperrow);
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} else {
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line_loop_paged_b(>,insert_pixel_2,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_2;
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break;
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case 3:
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line_start_paged(3);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_paged_a(>=,insert_pixel_3,+=3,+=bytesperrow*sy);
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} else {
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line_loop_paged_a(>,insert_pixel_3,-=3,+=bytesperrow*sy);
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}
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} else {
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sx *= 3;
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if(sy > 0) {
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line_loop_paged_b(>=,insert_pixel_3,+=sx,+=bytesperrow);
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} else {
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line_loop_paged_b(>,insert_pixel_3,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_3;
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break;
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case 4:
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line_start_paged(4);
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if (ax > ay) {
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if(sx > 0) {
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line_loop_paged_a(>=,insert_pixel_4,+=4,+=bytesperrow*sy);
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} else {
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line_loop_paged_a(>,insert_pixel_4,-=4,+=bytesperrow*sy);
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}
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} else {
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sx <<= 2;
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if(sy > 0) {
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line_loop_paged_b(>=,insert_pixel_4,+=sx,+=bytesperrow);
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} else {
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line_loop_paged_b(>,insert_pixel_4,+=sx,-=bytesperrow);
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}
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}
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insert_pixel_4;
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break;
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}
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}
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if (!vp) {
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if (ax > ay) {
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int d = ay - (ax >> 1);
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while (x != x2) {
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setpixel (x, y, c);
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if (d > 0 || (d == 0 && sx == 1)) {
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y += sy;
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d -= ax;
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}
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x += sx;
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d += ay;
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}
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} else {
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int d = ax - (ay >> 1);
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while (y != y2) {
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setpixel (x, y, c);
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if (d > 0 || (d == 0 && sy == 1)) {
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x += sx;
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d -= ay;
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}
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y += sy;
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d += ax;
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}
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}
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setpixel (x, y, c);
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}
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#endif
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}
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static void gl_setcirclepixels(int x, int y, int sx, int sy, int c)
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{
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if (__clip) {
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int z = max(x, y);
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if (sx - z < __clipx1 || sx + z > __clipx2
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|| sy - z < __clipy1 || sy + z > __clipy2) {
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/* use setpixel clipping */
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gl_setpixel(sx + x, sy + y, c);
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gl_setpixel(sx - x, sy + y, c);
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gl_setpixel(sx + x, sy - y, c);
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gl_setpixel(sx - x, sy - y, c);
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gl_setpixel(sx + y, sy + x, c);
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gl_setpixel(sx - y, sy + x, c);
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gl_setpixel(sx + y, sy - x, c);
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gl_setpixel(sx - y, sy - x, c);
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return;
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}
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}
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setpixel(sx + x, sy + y, c);
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setpixel(sx - x, sy + y, c);
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setpixel(sx + x, sy - y, c);
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setpixel(sx - x, sy - y, c);
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setpixel(sx + y, sy + x, c);
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setpixel(sx - y, sy + x, c);
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setpixel(sx + y, sy - x, c);
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setpixel(sx - y, sy - x, c);
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}
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void gl_circle(int sx, int sy, int r, int c)
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{
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int x, y, d;
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if (r < 1) {
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gl_setpixel(sx, sy, c);
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return;
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}
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if (__clip)
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if (sx + r < __clipx1 || sx - r > __clipx2
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|| sy + r < __clipy1 || sy - r > __clipy2)
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return;
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x = 0;
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y = r;
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d = 1 - r;
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gl_setcirclepixels(x, y, sx, sy, c);
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while (x < y) {
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if (d < 0)
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d += x * 2 + 3;
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else {
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d += x * 2 - y * 2 + 5;
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y--;
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}
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x++;
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gl_setcirclepixels(x, y, sx, sy, c);
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}
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}
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void gl_fillcircle(int sx, int sy, int r, int c)
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{
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int x = 0,
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y = r,
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d = 1 - r;
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if (r < 1) {
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gl_setpixel(sx, sy, c);
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return;
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}
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if (__clip)
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if (sx + r < __clipx1 || sx - r > __clipx2
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|| sy + r < __clipy1 || sy - r > __clipy2)
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return;
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gl_hline(sx - x, sy + y, sx + x, c);
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gl_hline(sx - x, sy - y, sx + x, c);
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gl_hline(sx - y, sy + x, sx + y, c);
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gl_hline(sx - y, sy - x, sx + y, c);
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while (x < y)
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{
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if (d < 0)
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{
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d += x * 2 + 3;
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} else {
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d += x * 2 - y * 2 + 5;
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y--;
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}
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x++;
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gl_hline(sx - x, sy + y, sx + x, c);
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gl_hline(sx - x, sy - y, sx + x, c);
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gl_hline(sx - y, sy + x, sx + y, c);
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gl_hline(sx - y, sy - x, sx + y, c);
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}
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}
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void gl_bcircle(int sx, int sy, int r, int c, int fill)
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{
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int x = 0,
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y = r,
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d = 2 * (1 - r);
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if (r < 1) {
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gl_setpixel(sx, sy, c);
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return;
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}
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if (__clip)
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if (sx + r < __clipx1 || sx - r > __clipx2
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|| sy + r < __clipy1 || sy - r > __clipy2)
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return;
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|
while (y >= 0)
|
|
{
|
|
if (fill == 0)
|
|
{
|
|
gl_setpixel(sx + x, sy + y, c);
|
|
gl_setpixel(sx + x, sy - y, c);
|
|
gl_setpixel(sx - x, sy + y, c);
|
|
gl_setpixel(sx - x, sy - y, c);
|
|
} else {
|
|
gl_hline(sx - x, sy + y, sx + x, c);
|
|
gl_hline(sx - x, sy - y, sx + x, c);
|
|
}
|
|
if ((d + y) > 0)
|
|
{
|
|
y--;
|
|
d -= (2 * y * WIDTH / HEIGHT) - 1;
|
|
}
|
|
if (x > d)
|
|
{
|
|
x++;
|
|
d += (2 * x) + 1;
|
|
}
|
|
}
|
|
}
|