diff options
Diffstat (limited to 'gst/goom/drawmethods.c')
| -rw-r--r-- | gst/goom/drawmethods.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/gst/goom/drawmethods.c b/gst/goom/drawmethods.c new file mode 100644 index 00000000..929564da --- /dev/null +++ b/gst/goom/drawmethods.c @@ -0,0 +1,204 @@ +#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; + } + } +} |