/xbmc/visualizations/Goom/goom2k4-0/src/drawmethods.c
http://github.com/xbmc/xbmc · C · 203 lines · 129 code · 9 blank · 65 comment · 37 complexity · 8a9cc5a81ce760f5a54e536e79885d88 MD5 · raw file
- #include "drawmethods.h"
- #define DRAWMETHOD_PLUS(_out,_backbuf,_col) \
- {\
- int tra=0,i=0;\
- unsigned char *bra = (unsigned char*)&(_backbuf);\
- unsigned char *dra = (unsigned char*)&(_out);\
- unsigned char *cra = (unsigned char*)&(_col);\
- for (;i<4;i++) {\
- tra = *cra;\
- tra += *bra;\
- if (tra>255) tra=255;\
- *dra = tra;\
- ++dra;++cra;++bra;\
- }\
- }
- #define DRAWMETHOD DRAWMETHOD_PLUS(*p,*p,col)
- void draw_line (Pixel *data, int x1, int y1, int x2, int y2, int col, int screenx, int screeny)
- {
- int x, y, dx, dy, yy, xx;
- Pixel *p;
- if ((y1 < 0) || (y2 < 0) || (x1 < 0) || (x2 < 0) || (y1 >= screeny) || (y2 >= screeny) || (x1 >= screenx) || (x2 >= screenx)) return;
-
- /* clip to top edge
- if ((y1 < 0) && (y2 < 0))
- return;
-
- if (y1 < 0) {
- x1 += (y1 * (x1 - x2)) / (y2 - y1);
- y1 = 0;
- }
- if (y2 < 0) {
- x2 += (y2 * (x1 - x2)) / (y2 - y1);
- y2 = 0;
- }
-
- clip to bottom edge
- if ((y1 >= screeny) && (y2 >= screeny))
- return;
- if (y1 >= screeny) {
- x1 -= ((screeny - y1) * (x1 - x2)) / (y2 - y1);
- y1 = screeny - 1;
- }
- if (y2 >= screeny) {
- x2 -= ((screeny - y2) * (x1 - x2)) / (y2 - y1);
- y2 = screeny - 1;
- }
- clip to left edge
- if ((x1 < 0) && (x2 < 0))
- return;
- if (x1 < 0) {
- y1 += (x1 * (y1 - y2)) / (x2 - x1);
- x1 = 0;
- }
- if (x2 < 0) {
- y2 += (x2 * (y1 - y2)) / (x2 - x1);
- x2 = 0;
- }
- clip to right edge
- if ((x1 >= screenx) && (x2 >= screenx))
- return;
- if (x1 >= screenx) {
- y1 -= ((screenx - x1) * (y1 - y2)) / (x2 - x1);
- x1 = screenx - 1;
- }
- if (x2 >= screenx) {
- y2 -= ((screenx - x2) * (y1 - y2)) / (x2 - x1);
- x2 = screenx - 1;
- }
- */
-
- dx = x2 - x1;
- dy = y2 - y1;
- if (x1 > x2) {
- int tmp;
- tmp = x1;
- x1 = x2;
- x2 = tmp;
- tmp = y1;
- y1 = y2;
- y2 = tmp;
- dx = x2 - x1;
- dy = y2 - y1;
- }
- /* vertical line */
- if (dx == 0) {
- if (y1 < y2) {
- p = &(data[(screenx * y1) + x1]);
- for (y = y1; y <= y2; y++) {
- DRAWMETHOD;
- p += screenx;
- }
- }
- else {
- p = &(data[(screenx * y2) + x1]);
- for (y = y2; y <= y1; y++) {
- DRAWMETHOD;
- p += screenx;
- }
- }
- return;
- }
- /* horizontal line */
- if (dy == 0) {
- if (x1 < x2) {
- p = &(data[(screenx * y1) + x1]);
- for (x = x1; x <= x2; x++) {
- DRAWMETHOD;
- p++;
- }
- return;
- }
- else {
- p = &(data[(screenx * y1) + x2]);
- for (x = x2; x <= x1; x++) {
- DRAWMETHOD;
- p++;
- }
- return;
- }
- }
- /* 1 */
- /* \ */
- /* \ */
- /* 2 */
- if (y2 > y1) {
- /* steep */
- if (dy > dx) {
- dx = ((dx << 16) / dy);
- x = x1 << 16;
- for (y = y1; y <= y2; y++) {
- xx = x >> 16;
- p = &(data[(screenx * y) + xx]);
- DRAWMETHOD;
- if (xx < (screenx - 1)) {
- p++;
- /* DRAWMETHOD; */
- }
- x += dx;
- }
- return;
- }
- /* shallow */
- else {
- dy = ((dy << 16) / dx);
- y = y1 << 16;
- for (x = x1; x <= x2; x++) {
- yy = y >> 16;
- p = &(data[(screenx * yy) + x]);
- DRAWMETHOD;
- if (yy < (screeny - 1)) {
- p += screeny;
- /* DRAWMETHOD; */
- }
- y += dy;
- }
- }
- }
- /* 2 */
- /* / */
- /* / */
- /* 1 */
- else {
- /* steep */
- if (-dy > dx) {
- dx = ((dx << 16) / -dy);
- x = (x1 + 1) << 16;
- for (y = y1; y >= y2; y--) {
- xx = x >> 16;
- p = &(data[(screenx * y) + xx]);
- DRAWMETHOD;
- if (xx < (screenx - 1)) {
- p--;
- /* DRAWMETHOD; */
- }
- x += dx;
- }
- return;
- }
- /* shallow */
- else {
- dy = ((dy << 16) / dx);
- y = y1 << 16;
- for (x = x1; x <= x2; x++) {
- yy = y >> 16;
- p = &(data[(screenx * yy) + x]);
- DRAWMETHOD;
- if (yy < (screeny - 1)) {
- p += screeny;
- /* DRAWMETHOD; */
- }
- y += dy;
- }
- return;
- }
- }
- }