mirror of
https://github.com/kichikuou/xsystem35-sdl2.git
synced 2026-10-01 03:08:14 +03:00
115 lines
3.0 KiB
C
115 lines
3.0 KiB
C
// 拡大縮小
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static surface_t *stretch(surface_t *src, int dw, int dh, int mirror) {
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surface_t *dst = calloc(1, sizeof(surface_t));
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float a1, a2, xd, yd;
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int sw, sh;
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int *row, *col;
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int x, y;
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BYTE *sdata, *ddata;
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dst->width = dw;
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dst->height = dh;
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dst->depth = src->depth;
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dst->bytes_per_line = dw * src->bytes_per_pixel;
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dst->bytes_per_pixel = src->bytes_per_pixel;
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if (src->pixel) {
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dst->pixel = malloc(dh * dst->bytes_per_line);
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}
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if (src->alpha) {
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dst->alpha = malloc(dw * dh);
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}
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sdata = GETOFFSET_PIXEL(src, 0, 0);
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ddata = GETOFFSET_PIXEL(dst, 0, 0);
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sw = src->width;
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sh = src->height;
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a1 = (float)sw / (float)dw;
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a2 = (float)sh / (float)dh;
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row = malloc(sizeof(int) * dw);
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// 1おおきくして初期化しないと col[dw-1]とcol[dw]が同じになる
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// 可能性がある。
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col = calloc(dh +1, sizeof(int));
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if (mirror & 1) {
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/* 上下反転 added by tajiri@wizard */
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for (yd = sh - a2, y = 0; y < dh; y++) {
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col[y] = yd; yd -= a2;
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}
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} else {
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for (yd = 0.0, y = 0; y < dh; y++) {
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col[y] = yd; yd += a2;
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}
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}
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if (mirror & 2) {
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/* 左右反転 added by tajiri@wizard */
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for (xd = sw - a1, x = 0; x < dw; x++) {
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row[x] = xd; xd -= a1;
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}
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} else {
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for (xd = 0.0, x = 0; x < dw; x++) {
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row[x] = xd; xd += a1;
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}
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}
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#define SCALEDCOPYAREA(type) { \
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int x, y; \
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type *sl, *dl; \
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BYTE *_sl, *_dl; \
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for (y = 0; y < dh; y++) { \
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sl = (type *)(sdata + *(y + col) * src->bytes_per_line);\
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dl = (type *)(ddata + y * dst->bytes_per_line);\
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for (x = 0; x < dw; x++) { \
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*(dl + x) = *(sl + *(row + x)); \
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} \
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_dl = (BYTE *)dl; \
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while(*(col + y) == *(col + y + 1)) { \
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_sl = _dl; \
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_dl += dst->bytes_per_line; \
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memcpy(_dl, _sl, dw * sizeof(type)); \
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y++; \
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} \
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}}
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switch(dst->depth) {
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case 8:
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SCALEDCOPYAREA(BYTE); break;
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case 16:
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SCALEDCOPYAREA(WORD); break;
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case 24:
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case 32:
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SCALEDCOPYAREA(DWORD); break;
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default:
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break;
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}
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if (src->alpha) {
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int x, y;
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BYTE *sl, *dl;
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BYTE *_sl, *_dl;
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sdata = GETOFFSET_ALPHA(src, 0, 0);
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ddata = GETOFFSET_ALPHA(dst, 0, 0);
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for (y = 0; y < dh; y++) {
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sl = (BYTE *)(sdata + *(y + col) * src->width);
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dl = (BYTE *)(ddata + y * dst->width);
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for (x = 0; x < dw; x++) {
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*(dl + x) = *(sl + *(row + x));
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}
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_dl = (BYTE *)dl;
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while(*(col + y) == *(col + y + 1)) {
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_sl = _dl;
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_dl += dst->width;
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memcpy(_dl, _sl, dw);
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y++;
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}
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}
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}
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free(row);
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free(col);
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return dst;
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}
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