/*
SDL_rotozoom.c - rotozoomer for 32bit or 8bit surfaces
LGPL (c) A. Schiffler
This is a trimmed down version of SDL_rotozoom, from the
SDL_gfx library. This source is from version 2.0.3. What's
left is only what's needed for the rotozoom function.
*/
#define NO_PYGAME_C_API
#include "pygame.h"
#include "math.h"
typedef struct tColorRGBA {
Uint8 r; Uint8 g; Uint8 b; Uint8 a;
} tColorRGBA;
#define VALUE_LIMIT 0.001
#ifndef MAX
#define MAX(a,b) (((a) > (b)) ? (a) : (b))
#endif
#ifndef M_PI
#define M_PI 3.141592654
#endif
/*
32bit Zoomer with optional anti-aliasing by bilinear interpolation.
Zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.
*/
int zoomSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int smooth)
{
int x, y, sx, sy, *sax, *say, *csax, *csay, csx, csy, ex, ey, t1, t2, sstep;
tColorRGBA *c00, *c01, *c10, *c11;
tColorRGBA *sp, *csp, *dp;
int sgap, dgap;
/*
* Variable setup
*/
if (smooth) {
/*
* For interpolation: assume source dimension is one pixel
*/
/*
* smaller to avoid overflow on right and bottom edge.
*/
sx = (int) (65536.0 * (float) (src->w - 1) / (float) dst->w);
sy = (int) (65536.0 * (float) (src->h - 1) / (float) dst->h);
} else {
sx = (int) (65536.0 * (float) src->w / (float) dst->w);
sy = (int) (65536.0 * (float) src->h / (float) dst->h);
}
/*
* Allocate memory for row increments
*/
if ((sax = (int *) malloc((dst->w + 1) * sizeof(Uint32))) == NULL) {
return (-1);
}
if ((say = (int *) malloc((dst->h + 1) * sizeof(Uint32))) == NULL) {
free(sax);
return (-1);
}
/*
* Precalculate row increments
*/
csx = 0;
csax = sax;
for (x = 0; x <= dst->w; x++) {
*csax = csx;
csax++;
csx &= 0xffff;
csx += sx;
}
csy = 0;
csay = say;
for (y = 0; y <= dst->h; y++) {
*csay = csy;
csay++;
csy &= 0xffff;
csy += sy;
}
/*
* Pointer setup
*/
sp = csp = (tColorRGBA *) src->pixels;
dp = (tColorRGBA *) dst->pixels;
sgap = src->pitch - src->w * 4;
dgap = dst->pitch - dst->w * 4;
/*
* Switch between interpolating and non-interpolating code
*/
if (smooth) {
/*
* Interpolating Zoom
*/
/*
* Scan destination
*/
csay = say;
for (y = 0; y < dst->h; y++) {
/*
* Setup color source pointers
*/
c00 = csp;
c01 = csp;
c01++;
c10 = (tColorRGBA *) ((Uint8 *) csp + src->pitch);
c11 = c10;
c11++;
csax = sax;
for (x = 0; x < dst->w; x++) {
/*
* Interpolate colors
*/
ex = (*csax & 0xffff);
ey = (*csay & 0xffff);
t1 = ((((c01->r - c00->r) * ex) >> 16) + c00->r) & 0xff;
t2 = ((((c11->r - c10->r) * ex) >> 16) + c10->r) & 0xff;
dp->r = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01->g - c00->g) * ex) >> 16) + c00->g) & 0xff;
t2 = ((((c11->g - c10->g) * ex) >> 16) + c10->g) & 0xff;
dp->g = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01->b - c00->b) * ex) >> 16) + c00->b) & 0xff;
t2 = ((((c11->b - c10->b) * ex) >> 16) + c10->b) & 0xff;
dp->b = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01->a - c00->a) * ex) >> 16) + c00->a) & 0xff;
t2 = ((((c11->a - c10->a) * ex) >> 16) + c10->a) & 0xff;
dp->a = (((t2 - t1) * ey) >> 16) + t1;
/*
* Advance source pointers
*/
csax++;
sstep = (*csax >> 16);
c00 += sstep;
c01 += sstep;
c10 += sstep;
c11 += sstep;
/*
* Advance destination pointer
*/
dp++;
}
/*
* Advance source pointer
*/
csay++;
csp = (tColorRGBA *) ((Uint8 *) csp + (*csay >> 16) * src->pitch);
/*
* Advance destination pointers
*/
dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
}
} else {
/*
* Non-Interpolating Zoom
*/
csay = say;
for (y = 0; y < dst->h; y++) {
sp = csp;
csax = sax;
for (x = 0; x < dst->w; x++) {
/*
* Draw
*/
*dp = *sp;
/*
* Advance source pointers
*/
csax++;
sp += (*csax >> 16);
/*
* Advance destination pointer
*/
dp++;
}
/*
* Advance source pointer
*/
csay++;
csp = (tColorRGBA *) ((Uint8 *) csp + (*csay >> 16) * src->pitch);
/*
* Advance destination pointers
*/
dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
}
}
/*
* Remove temp arrays
*/
free(sax);
free(say);
return (0);
}
/*
32bit Rotozoomer with optional anti-aliasing by bilinear interpolation.
Rotates and zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.
*/
void transformSurfaceRGBA(SDL_Surface * src, SDL_Surface * dst, int cx, int cy, int isin, int icos, int smooth)
{
int x, y, t1, t2, dx, dy, xd, yd, sdx, sdy, ax, ay, ex, ey, sw, sh;
tColorRGBA c00, c01, c10, c11;
tColorRGBA *pc, *sp;
int gap;
/*
* Variable setup
*/
xd = ((src->w - dst->w) << 15);
yd = ((src->h - dst->h) << 15);
ax = (cx << 16) - (icos * cx);
ay = (cy << 16) - (isin * cx);
sw = src->w - 1;
sh = src->h - 1;
pc = dst->pixels;
gap = dst->pitch - dst->w * 4;
/*
* Switch between interpolating and non-interpolating code
*/
if (smooth) {
for (y = 0; y < dst->h; y++) {
dy = cy - y;
sdx = (ax + (isin * dy)) + xd;
sdy = (ay - (icos * dy)) + yd;
for (x = 0; x < dst->w; x++) {
dx = (sdx >> 16);
dy = (sdy >> 16);
if ((dx >= -1) && (dy >= -1) && (dx < src->w) && (dy < src->h)) {
if ((dx >= 0) && (dy >= 0) && (dx < sw) && (dy < sh)) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
sp += dx;
c00 = *sp;
sp += 1;
c01 = *sp;
sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
sp -= 1;
c10 = *sp;
sp += 1;
c11 = *sp;
} else if ((dx == sw) && (dy == sh)) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
sp += dx;
c00 = *sp;
c01 = *sp;
c10 = *sp;
c11 = *sp;
} else if ((dx == -1) && (dy == -1)) {
sp = (tColorRGBA *) (src->pixels);
c00 = *sp;
c01 = *sp;
c10 = *sp;
c11 = *sp;
} else if ((dx == -1) && (dy == sh)) {
sp = (tColorRGBA *) (src->pixels);
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
c00 = *sp;
c01 = *sp;
c10 = *sp;
c11 = *sp;
} else if ((dx == sw) && (dy == -1)) {
sp = (tColorRGBA *) (src->pixels);
sp += dx;
c00 = *sp;
c01 = *sp;
c10 = *sp;
c11 = *sp;
} else if (dx == -1) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
c00 = *sp;
c01 = *sp;
c10 = *sp;
sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
c11 = *sp;
} else if (dy == -1) {
sp = (tColorRGBA *) (src->pixels);
sp += dx;
c00 = *sp;
c01 = *sp;
c10 = *sp;
sp += 1;
c11 = *sp;
} else if (dx == sw) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
sp += dx;
c00 = *sp;
c01 = *sp;
sp = (tColorRGBA *) ((Uint8 *) sp + src->pitch);
c10 = *sp;
c11 = *sp;
} else if (dy == sh) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
sp += dx;
c00 = *sp;
sp += 1;
c01 = *sp;
c10 = *sp;
c11 = *sp;
} else {
// NOTE: a catchall to appease gcc4 warnings...
// Probably should not get here. we'll see.
// old behaviour would be to use the previous pixel, from the previous loop.
sp = (tColorRGBA *) (src->pixels);
c00 = *sp;
c01 = *sp;
c10 = *sp;
c11 = *sp;
}
/*
* Interpolate colors
*/
ex = (sdx & 0xffff);
ey = (sdy & 0xffff);
t1 = ((((c01.r - c00.r) * ex) >> 16) + c00.r) & 0xff;
t2 = ((((c11.r - c10.r) * ex) >> 16) + c10.r) & 0xff;
pc->r = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01.g - c00.g) * ex) >> 16) + c00.g) & 0xff;
t2 = ((((c11.g - c10.g) * ex) >> 16) + c10.g) & 0xff;
pc->g = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01.b - c00.b) * ex) >> 16) + c00.b) & 0xff;
t2 = ((((c11.b - c10.b) * ex) >> 16) + c10.b) & 0xff;
pc->b = (((t2 - t1) * ey) >> 16) + t1;
t1 = ((((c01.a - c00.a) * ex) >> 16) + c00.a) & 0xff;
t2 = ((((c11.a - c10.a) * ex) >> 16) + c10.a) & 0xff;
pc->a = (((t2 - t1) * ey) >> 16) + t1;
}
sdx += icos;
sdy += isin;
pc++;
}
pc = (tColorRGBA *) ((Uint8 *) pc + gap);
}
} else {
for (y = 0; y < dst->h; y++) {
dy = cy - y;
sdx = (ax + (isin * dy)) + xd;
sdy = (ay - (icos * dy)) + yd;
for (x = 0; x < dst->w; x++) {
dx = (short) (sdx >> 16);
dy = (short) (sdy >> 16);
if ((dx >= 0) && (dy >= 0) && (dx < src->w) && (dy < src->h)) {
sp = (tColorRGBA *) ((Uint8 *) src->pixels + src->pitch * dy);
sp += dx;
*pc = *sp;
}
sdx += icos;
sdy += isin;
pc++;
}
pc = (tColorRGBA *) ((Uint8 *) pc + gap);
}
}
}
/*
rotozoomSurface()
Rotates and zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface.
'angle' is the rotation in degrees. 'zoom' a scaling factor. If 'smooth' is 1
then the destination 32bit surface is anti-aliased. If the surface is not 8bit
or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly.
*/
#define VALUE_LIMIT 0.001
/* Local rotozoom-size function with trig result return */
void rotozoomSurfaceSizeTrig(int width, int height, double angle, double zoom, int *dstwidth, int *dstheight,
double *canglezoom, double *sanglezoom)
{
double x, y, cx, cy, sx, sy;
double radangle;
int dstwidthhalf, dstheighthalf;
/*
* Determine destination width and height by rotating a centered source box
*/
radangle = angle * (M_PI / 180.0);
*sanglezoom = sin(radangle);
*canglezoom = cos(radangle);
*sanglezoom *= zoom;
*canglezoom *= zoom;
x = width / 2;
y = height / 2;
cx = *canglezoom * x;
cy = *canglezoom * y;
sx = *sanglezoom * x;
sy = *sanglezoom * y;
dstwidthhalf = MAX((int)
ceil(MAX(MAX(MAX(fabs(cx + sy), fabs(cx - sy)), fabs(-cx + sy)), fabs(-cx - sy))), 1);
dstheighthalf = MAX((int)
ceil(MAX(MAX(MAX(fabs(sx + cy), fabs(sx - cy)), fabs(-sx + cy)), fabs(-sx - cy))), 1);
*dstwidth = 2 * dstwidthhalf;
*dstheight = 2 * dstheighthalf;
}
/* Publically available rotozoom-size function */
void rotozoomSurfaceSize(int width, int height, double angle, double zoom, int *dstwidth, int *dstheight)
{
double dummy_sanglezoom, dummy_canglezoom;
rotozoomSurfaceSizeTrig(width, height, angle, zoom, dstwidth, dstheight, &dummy_sanglezoom, &dummy_canglezoom);
}
/*
zoomSurface()
Zoomes a 32bit or 8bit 'src' surface to newly created 'dst' surface.
'zoomx' and 'zoomy' are scaling factors for width and height. If 'smooth' is 1
then the destination 32bit surface is anti-aliased. If the surface is not 8bit
or 32bit RGBA/ABGR it will be converted into a 32bit RGBA format on the fly.
*/
void zoomSurfaceSize(int width, int height, double zoomx, double zoomy, int *dstwidth, int *dstheight)
{
/*
* Sanity check zoom factors
*/
if (zoomx < VALUE_LIMIT) {
zoomx = VALUE_LIMIT;
}
if (zoomy < VALUE_LIMIT) {
zoomy = VALUE_LIMIT;
}
/*
* Calculate target size
*/
*dstwidth = (int) ((double) width * zoomx);
*dstheight = (int) ((double) height * zoomy);
if (*dstwidth < 1) {
*dstwidth = 1;
}
if (*dstheight < 1) {
*dstheight = 1;
}
}
/* Publically available rotozoom function */
SDL_Surface *rotozoomSurface(SDL_Surface * src, double angle, double zoom, int smooth)
{
SDL_Surface *rz_src;
SDL_Surface *rz_dst;
double zoominv;
double sanglezoom, canglezoom, sanglezoominv, canglezoominv;
int dstwidthhalf, dstwidth, dstheighthalf, dstheight;
int is32bit;
int src_converted;
/*
* Sanity check
*/
if (src == NULL)
return (NULL);
/*
* Determine if source surface is 32bit or 8bit
*/
is32bit = (src->format->BitsPerPixel == 32);
if ((is32bit) || (src->format->BitsPerPixel == 8)) {
/*
* Use source surface 'as is'
*/
rz_src = src;
src_converted = 0;
} else {
/*
* New source surface is 32bit with a defined RGBA ordering
*/
rz_src =
SDL_CreateRGBSurface(SDL_SWSURFACE, src->w, src->h, 32, 0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000);
SDL_BlitSurface(src, NULL, rz_src, NULL);
src_converted = 1;
is32bit = 1;
}
/*
* Sanity check zoom factor
*/
if (zoom < VALUE_LIMIT) {
zoom = VALUE_LIMIT;
}
zoominv = 65536.0 / (zoom * zoom);
/*
* Check if we have a rotozoom or just a zoom
*/
if (fabs(angle) > VALUE_LIMIT) {
/*
* Angle!=0: full rotozoom
*/
/*
* -----------------------
*/
/* Determine target size */
rotozoomSurfaceSizeTrig(rz_src->w, rz_src->h, angle, zoom, &dstwidth, &dstheight, &canglezoom, &sanglezoom);
/*
* Calculate target factors from sin/cos and zoom
*/
sanglezoominv = sanglezoom;
canglezoominv = canglezoom;
sanglezoominv *= zoominv;
canglezoominv *= zoominv;
/* Calculate half size */
dstwidthhalf = dstwidth / 2;
dstheighthalf = dstheight / 2;
/*
* Alloc space to completely contain the rotated surface
*/
rz_dst = NULL;
/*
* Target surface is 32bit with source RGBA/ABGR ordering
*/
rz_dst =
SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
rz_src->format->Rmask, rz_src->format->Gmask,
rz_src->format->Bmask, rz_src->format->Amask);
/*
* Lock source surface
*/
SDL_LockSurface(rz_src);
/*
* Check which kind of surface we have
*/
/*
* Call the 32bit transformation routine to do the rotation (using alpha)
*/
transformSurfaceRGBA(rz_src, rz_dst, dstwidthhalf, dstheighthalf,
(int) (sanglezoominv), (int) (canglezoominv), smooth);
/*
* Turn on source-alpha support
*/
SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
/*
* Unlock source surface
*/
SDL_UnlockSurface(rz_src);
} else {
/*
* Angle=0: Just a zoom
*/
/*
* --------------------
*/
/*
* Calculate target size
*/
zoomSurfaceSize(rz_src->w, rz_src->h, zoom, zoom, &dstwidth, &dstheight);
/*
* Alloc space to completely contain the zoomed surface
*/
rz_dst = NULL;
/*
* Target surface is 32bit with source RGBA/ABGR ordering
*/
rz_dst =
SDL_CreateRGBSurface(SDL_SWSURFACE, dstwidth, dstheight, 32,
rz_src->format->Rmask, rz_src->format->Gmask,
rz_src->format->Bmask, rz_src->format->Amask);
/*
* Lock source surface
*/
SDL_LockSurface(rz_src);
/*
* Check which kind of surface we have
*/
/*
* Call the 32bit transformation routine to do the zooming (using alpha)
*/
zoomSurfaceRGBA(rz_src, rz_dst, smooth);
/*
* Turn on source-alpha support
*/
SDL_SetAlpha(rz_dst, SDL_SRCALPHA, 255);
/*
* Unlock source surface
*/
SDL_UnlockSurface(rz_src);
}
/*
* Cleanup temp surface
*/
if (src_converted) {
SDL_FreeSurface(rz_src);
}
/*
* Return destination surface
*/
return (rz_dst);
}
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