0
This repository has been archived on 2025-04-25. You can view files and clone it. You cannot open issues or pull requests or push a commit.
Files
Minecraft-Overviewer/iterate.c
Andrew Chin 66a9306a29 Experimental code to provide a C implementation of chunk_render
Please see the TODO comments in iterate.c

None of the lighting, spawning, night, or cave modes work with this
version.
2011-03-06 00:30:40 -05:00

374 lines
11 KiB
C

#include <Python.h>
#include <numpy/arrayobject.h>
#include <Imaging.h>
/* like (a * b + 127) / 255), but much faster on most platforms
from PIL's _imaging.c */
#define MULDIV255(a, b, tmp) \
(tmp = (a) * (b) + 128, ((((tmp) >> 8) + (tmp)) >> 8))
typedef struct
{
PyObject_HEAD
Imaging image;
} ImagingObject;
// macro for getting blockID from a chunk of memory
#define getBlock(blockThing, x,y,z) blockThing[ y + ( z * 128 + ( x * 128 * 16) ) ]
static inline int isTransparent(unsigned char b) {
// TODO expand this to include all transparent blocks
return b == 0;
}
static Imaging imaging_python_to_c(PyObject* obj)
{
PyObject* im;
Imaging image;
/* first, get the 'im' attribute */
im = PyObject_GetAttrString(obj, "im");
if (!im)
return NULL;
/* make sure 'im' is the right type */
if (strcmp(im->ob_type->tp_name, "ImagingCore") != 0)
{
/* it's not -- raise an error and exit */
PyErr_SetString(PyExc_TypeError, "image attribute 'im' is not a core Imaging type");
return NULL;
}
image = ((ImagingObject*)im)->image;
Py_DECREF(im);
return image;
}
// TODO refact iterate.c and _composite.c so share implementations
static PyObject* alpha_over(PyObject* dest, PyObject* t, int imgx, int imgy)
{
/* raw input python variables */
PyObject * src, * mask;
/* libImaging handles */
Imaging imDest, imSrc, imMask;
/* cached blend properties */
int src_has_alpha, mask_offset, mask_stride;
/* destination position and size */
int dx, dy, xsize, ysize;
/* source position */
int sx, sy;
/* iteration variables */
unsigned int x, y, i;
/* temporary calculation variables */
int tmp1, tmp2, tmp3;
src = PyTuple_GET_ITEM(t, 0);
mask = PyTuple_GET_ITEM(t, 1);
if (mask == Py_None) {
printf("mask is none\n");
Py_INCREF(mask);
mask = src;
}
//if (!PyArg_ParseTuple(args, "OOOO", &dest, &src, &pos, &mask))
// return NULL;
imDest = imaging_python_to_c(dest);
imSrc = imaging_python_to_c(src);
imMask = imaging_python_to_c(mask);
//printf("alpha1\n");
if (!imDest || !imSrc || !imMask) {
PyErr_SetString(PyExc_ValueError, "dest, src, or mask is missing");
return NULL;
}
//printf("alpha2\n");
/* check the various image modes, make sure they make sense */
if (strcmp(imDest->mode, "RGBA") != 0)
{
PyErr_SetString(PyExc_ValueError, "given destination image does not have mode \"RGBA\"");
return NULL;
}
if (strcmp(imSrc->mode, "RGBA") != 0 && strcmp(imSrc->mode, "RGB") != 0)
{
PyErr_SetString(PyExc_ValueError, "given source image does not have mode \"RGBA\" or \"RGB\"");
return NULL;
}
if (strcmp(imMask->mode, "RGBA") != 0 && strcmp(imMask->mode, "L") != 0)
{
PyErr_SetString(PyExc_ValueError, "given mask image does not have mode \"RGBA\" or \"L\"");
return NULL;
}
/* make sure mask size matches src size */
if (imSrc->xsize != imMask->xsize || imSrc->ysize != imMask->ysize)
{
PyErr_SetString(PyExc_ValueError, "mask and source image sizes do not match");
return NULL;
}
//printf("alpha3\n");
/* set up flags for the src/mask type */
src_has_alpha = (imSrc->pixelsize == 4 ? 1 : 0);
/* how far into image the first alpha byte resides */
mask_offset = (imMask->pixelsize == 4 ? 3 : 0);
/* how many bytes to skip to get to the next alpha byte */
mask_stride = imMask->pixelsize;
//printf("alpha4\n");
/* destination position read */
//if (!PyArg_ParseTuple(pos, "iiii", &dx, &dy, &xsize, &ysize))
//{
// PyErr_SetString(PyExc_TypeError, "given blend destination rect is not valid");
// return NULL;
//}
dx = imgx;
dy = imgy;
xsize = imSrc->xsize;
ysize = imSrc->ysize;
//printf("xsize/ysize %d/%d\n", xsize, ysize);
//printf("alpha5\n");
/* set up the source position, size and destination position */
/* handle negative dest pos */
if (dx < 0)
{
sx = -dx;
dx = 0;
} else {
sx = 0;
}
if (dy < 0)
{
sy = -dy;
dy = 0;
} else {
sy = 0;
}
/* set up source dimensions */
xsize -= sx;
ysize -= sy;
//printf("imDest->xsize=%d imDest->yize=%d\n", imDest->xsize, imDest->ysize);
/* clip dimensions, if needed */
if (dx + xsize > imDest->xsize)
xsize = imDest->xsize - dx;
if (dy + ysize > imDest->ysize)
ysize = imDest->ysize - dy;
/* check that there remains any blending to be done */
if (xsize <= 0 || ysize <= 0)
{
/* nothing to do, return */
Py_INCREF(dest);
return dest;
}
for (y = 0; y < ysize; y++)
{
UINT8* out = (UINT8*) imDest->image[dy + y] + dx*4;
UINT8* outmask = (UINT8*) imDest->image[dy + y] + dx*4 + 3;
UINT8* in = (UINT8*) imSrc->image[sy + y] + sx*(imSrc->pixelsize);
UINT8* inmask = (UINT8*) imMask->image[sy + y] + sx*mask_stride + mask_offset;
for (x = 0; x < xsize; x++)
{
/* special cases */
if (*inmask == 255 || *outmask == 0)
{
*outmask = *inmask;
*out = *in;
out++, in++;
*out = *in;
out++, in++;
*out = *in;
out++, in++;
} else if (*inmask == 0) {
/* do nothing -- source is fully transparent */
out += 3;
in += 3;
} else {
/* general case */
int alpha = *inmask + MULDIV255(*outmask, 255 - *inmask, tmp1);
for (i = 0; i < 3; i++)
{
/* general case */
*out = MULDIV255(*in, *inmask, tmp1) + MULDIV255(MULDIV255(*out, *outmask, tmp2), 255 - *inmask, tmp3);
*out = (*out * 255) / alpha;
out++, in++;
}
*outmask = alpha;
}
out++;
if (src_has_alpha)
in++;
outmask += 4;
inmask += mask_stride;
}
}
Py_INCREF(dest);
return dest;
}
// TODO triple check this to make sure reference counting is correct
static PyObject*
chunk_render(PyObject *self, PyObject *args) {
PyObject *chunk;
PyObject *blockdata_expanded;
int xoff, yoff;
PyObject *img;
if (!PyArg_ParseTuple(args, "OOiiO", &chunk, &img, &xoff, &yoff, &blockdata_expanded))
return Py_BuildValue("i", "-1");
// tuple
PyObject *imgsize = PyObject_GetAttrString(img, "size");
PyObject *imgsize0_py = PySequence_GetItem(imgsize, 0);
PyObject *imgsize1_py = PySequence_GetItem(imgsize, 1);
Py_DECREF(imgsize);
int imgsize0 = PyInt_AsLong(imgsize0_py);
int imgsize1 = PyInt_AsLong(imgsize1_py);
Py_DECREF(imgsize0_py);
Py_DECREF(imgsize1_py);
// get the block data directly from numpy:
PyObject *blocks_py = PyObject_GetAttrString(chunk, "blocks");
char *blocks = PyArray_BYTES(blocks_py);
Py_DECREF(blocks_py);
//PyObject *left_blocks = PyObject_GetAttrString(chunk, "left_blocks");
//PyObject *right_blocks = PyObject_GetAttrString(chunk, "right_blocks");
//PyObject *transparent_blocks = PyObject_GetAttrString(chunk, "transparent_blocks");
PyObject *textures = PyImport_ImportModule("textures");
// TODO can these be global static? these don't change during program execution
PyObject *blockmap = PyObject_GetAttrString(textures, "blockmap");
PyObject *special_blocks = PyObject_GetAttrString(textures, "special_blocks");
PyObject *specialblockmap = PyObject_GetAttrString(textures, "specialblockmap");
Py_DECREF(textures);
//printf("render_loop\n");
int imgx, imgy;
int x, y, z;
for (x = 15; x > -1; x--) {
for (y = 0; y < 16; y++) {
imgx = xoff + x*12 + y*12;
imgy = yoff - x*6 + y*6 + 1632; // 1632 == 128*12 + 16*12//2
for (z = 0; z < 128; z++) {
//printf("c/imgx/%d\n", imgx);
//printf("c/imgy/%d\n", imgy);
if ((imgx >= imgsize0 + 24) || (imgx <= -24)) {
imgy -= 12; // NOTE: we need to do this at every continue
continue;
}
if ((imgy >= imgsize1 + 24) || (imgy <= -24)) {
imgy -= 12;
continue;
}
// get blockid
unsigned char block = getBlock(blocks, x, z, y); // Note the order: x,z,y
if (block == 0) {
imgy -= 12;
continue;
}
//printf("checking blockid %hhu\n", block);
PyObject *blockid = PyInt_FromLong(block); // TODO figure out how to DECREF this easily, instead at every 'continue'.
if ( (x != 0) && (y != 15) && (z != 127) &&
!isTransparent(getBlock(blocks, x-1, z, y)) &&
!isTransparent(getBlock(blocks, x, z+1, y)) &&
!isTransparent(getBlock(blocks, x, z, y+1)) ) {
imgy -= 12;
continue;
}
if (!PySequence_Contains(special_blocks, blockid)) {
//t = textures.blockmap[blockid]
PyObject *t = PyList_GetItem(blockmap, block);
// PyList_GetItem returns borrowed ref
if (t == Py_None) {
printf("t == Py_None. blockid=%d\n", block);
imgy -= 12;
continue;
}
// note that this version of alpha_over has a different signature than the
// version in _composite.c
alpha_over(img, t, imgx, imgy );
} else {
// this should be a pointer to a unsigned char
void* ancilData_p = PyArray_GETPTR3(blockdata_expanded, x, y, z);
unsigned char ancilData = *((unsigned char*)ancilData_p);
if (block == 85) { // fence. skip the generate_pseudo_ancildata for now
imgy -= 12;
continue;
}
PyObject *tmp = PyTuple_New(2);
Py_INCREF(blockid); // because SetItem steals
PyTuple_SetItem(tmp, 0, blockid);
PyTuple_SetItem(tmp, 1, PyInt_FromLong(ancilData));
PyObject *t = PyDict_GetItem(specialblockmap, tmp); // this is a borrowed reference. no need to decref
Py_DECREF(tmp);
if (t != NULL)
alpha_over(img, t, imgx, imgy );
imgy -= 12;
continue;
}
imgy -= 12;
}
}
}
Py_DECREF(blockmap);
Py_DECREF(special_blocks);
Py_DECREF(specialblockmap);
return Py_BuildValue("i",2);
}
static PyMethodDef IterateMethods[] = {
{"render_loop", chunk_render, METH_VARARGS,
"Renders stuffs"},
{NULL, NULL, 0, NULL} /* Sentinel */
};
PyMODINIT_FUNC
init_iterate(void)
{
(void) Py_InitModule("_iterate", IterateMethods);
import_array(); // for numpy
}