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Minecraft-Overviewer/overviewer_core/src/rendermode-lighting.c

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C

/*
* This file is part of the Minecraft Overviewer.
*
* Minecraft Overviewer is free software: you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* Minecraft Overviewer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
* Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with the Overviewer. If not, see <http://www.gnu.org/licenses/>.
*/
#include "overviewer.h"
#include <math.h>
/* figures out the black_coeff from a given skylight and blocklight,
used in lighting calculations */
static float calculate_darkness(unsigned char skylight, unsigned char blocklight) {
return 1.0f - powf(0.8f, 15.0 - MAX(blocklight, skylight));
}
/* loads the appropriate light data for the given (possibly non-local)
* coordinates, and returns a black_coeff this is exposed, so other (derived)
* rendermodes can use it
*
* authoratative is a return slot for whether or not this lighting calculation
* is true, or a guess. If we guessed, *authoratative will be false, but if it
* was calculated correctly from available light data, it will be true. You
* may (and probably should) pass NULL.
*/
inline unsigned char
estimate_blocklevel(RenderModeLighting *self, RenderState *state,
int x, int y, int z, int *authoratative) {
/* placeholders for later data arrays, coordinates */
PyObject *blocks = NULL;
PyObject *blocklight = NULL;
int local_x = x, local_y = y, local_z = z;
unsigned char block, blocklevel;
unsigned int average_count = 0, average_gather = 0, coeff = 0;
/* defaults to "guess" until told otherwise */
if (authoratative)
*authoratative = 0;
/* find out what chunk we're in, and translate accordingly */
if (x >= 0 && y < 16) {
blocks = state->blocks;
blocklight = self->blocklight;
} else if (x < 0) {
local_x += 16;
blocks = state->left_blocks;
blocklight = self->left_blocklight;
} else if (y >= 16) {
local_y -= 16;
blocks = state->right_blocks;
blocklight = self->right_blocklight;
}
/* make sure we have correctly-ranged coordinates */
if (!(local_x >= 0 && local_x < 16 &&
local_y >= 0 && local_y < 16 &&
local_z >= 0 && local_z < 128)) {
return 0;
}
/* also, make sure we have enough info to correctly calculate lighting */
if (blocks == Py_None || blocks == NULL ||
blocklight == Py_None || blocklight == NULL) {
return 0;
}
block = getArrayByte3D(blocks, local_x, local_y, local_z);
if (authoratative == NULL) {
int auth;
/* iterate through all surrounding blocks to take an average */
int dx, dy, dz, local_block;
for (dx = -1; dx <= 1; dx += 2) {
for (dy = -1; dy <= 1; dy += 2) {
for (dz = -1; dz <= 1; dz += 2) {
/* skip if block is out of range */
if (x+dx < 0 || x+dx >= 16 ||
y+dy < 0 || y+dy >= 16 ||
z+dz < 0 || z+dz >= 128) {
continue;
}
coeff = estimate_blocklevel(self, state, x+dx, y+dy, z+dz, &auth);
local_block = getArrayByte3D(blocks, x+dx, y+dy, z+dz);
/* only add if the block is transparent, this seems to look better than
using every block */
if (auth && is_transparent(local_block)) {
average_gather += coeff;
average_count++;
}
}
}
}
}
/* only return the average if at least one was authoratative */
if (average_count > 0) {
return average_gather / average_count;
}
blocklevel = getArrayByte3D(blocklight, local_x, local_y, local_z);
/* no longer a guess */
if (!(block == 44 || block == 53 || block == 67) && authoratative) {
*authoratative = 1;
}
return blocklevel;
}
inline float
get_lighting_coefficient(RenderModeLighting *self, RenderState *state,
int x, int y, int z) {
/* placeholders for later data arrays, coordinates */
PyObject *blocks = NULL;
PyObject *skylight = NULL;
PyObject *blocklight = NULL;
int local_x = x, local_y = y, local_z = z;
unsigned char block, skylevel, blocklevel;
/* find out what chunk we're in, and translate accordingly */
if (x >= 0 && y < 16) {
blocks = state->blocks;
skylight = self->skylight;
blocklight = self->blocklight;
} else if (x < 0) {
local_x += 16;
blocks = state->left_blocks;
skylight = self->left_skylight;
blocklight = self->left_blocklight;
} else if (y >= 16) {
local_y -= 16;
blocks = state->right_blocks;
skylight = self->right_skylight;
blocklight = self->right_blocklight;
}
/* make sure we have correctly-ranged coordinates */
if (!(local_x >= 0 && local_x < 16 &&
local_y >= 0 && local_y < 16 &&
local_z >= 0 && local_z < 128)) {
return self->calculate_darkness(15, 0);
}
/* also, make sure we have enough info to correctly calculate lighting */
if (blocks == Py_None || blocks == NULL ||
skylight == Py_None || skylight == NULL ||
blocklight == Py_None || blocklight == NULL) {
return self->calculate_darkness(15, 0);
}
block = getArrayByte3D(blocks, local_x, local_y, local_z);
skylevel = getArrayByte3D(skylight, local_x, local_y, local_z);
blocklevel = getArrayByte3D(blocklight, local_x, local_y, local_z);
/* special half-step handling */
if (block == 44 || block == 53 || block == 67) {
unsigned int upper_block;
/* stairs and half-blocks take the skylevel from the upper block if it's transparent */
if (local_z != 127) {
int upper_counter = 0;
/* but if the upper_block is one of these special half-steps, we need to look at *its* upper_block */
do {
upper_counter++;
upper_block = getArrayByte3D(blocks, local_x, local_y, local_z + upper_counter);
} while ((upper_block == 44 || upper_block == 54 || upper_block == 67) && local_z < 127);
if (is_transparent(upper_block)) {
skylevel = getArrayByte3D(skylight, local_x, local_y, local_z + upper_counter);
}
} else {
upper_block = 0;
skylevel = 15;
}
/* the block has a bad blocklevel, estimate it from neigborhood
* use given coordinates, no local ones! */
blocklevel = estimate_blocklevel(self, state, x, y, z, NULL);
}
if (block == 10 || block == 11) {
/* lava blocks should always be lit! */
return 0.0f;
}
return self->calculate_darkness(skylevel, blocklevel);
}
/* shades the drawn block with the given facemask/black_color, based on the
lighting results from (x, y, z) */
static inline void
do_shading_with_mask(RenderModeLighting *self, RenderState *state,
int x, int y, int z, PyObject *mask) {
float black_coeff;
/* first, check for occlusion if the block is in the local chunk */
if (x >= 0 && x < 16 && y >= 0 && y < 16 && z >= 0 && z < 128) {
unsigned char block = getArrayByte3D(state->blocks, x, y, z);
if (!is_transparent(block) && !render_mode_hidden(state->rendermode, x, y, z)) {
/* this face isn't visible, so don't draw anything */
return;
}
} else if (self->skip_sides && (x == -1) && (state->left_blocks != Py_None)) {
unsigned char block = getArrayByte3D(state->left_blocks, 15, state->y, state->z);
if (!is_transparent(block)) {
/* the same thing but for adjacent chunks, this solves an
ugly black doted line between chunks in night rendermode.
This wouldn't be necessary if the textures were truly
tessellate-able */
return;
}
} else if (self->skip_sides && (y == 16) && (state->right_blocks != Py_None)) {
unsigned char block = getArrayByte3D(state->right_blocks, state->x, 0, state->z);
if (!is_transparent(block)) {
/* the same thing but for adjacent chunks, this solves an
ugly black doted line between chunks in night rendermode.
This wouldn't be necessary if the textures were truly
tessellate-able */
return;
}
}
black_coeff = get_lighting_coefficient(self, state, x, y, z);
black_coeff *= self->shade_strength;
alpha_over_full(state->img, self->black_color, mask, black_coeff, state->imgx, state->imgy, 0, 0);
}
static int
rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
RenderModeLighting* self;
/* first, chain up */
int ret = rendermode_normal.start(data, state, options);
if (ret != 0)
return ret;
self = (RenderModeLighting *)data;
/* skip sides by default */
self->skip_sides = 1;
self->shade_strength = 1.0;
if (!render_mode_parse_option(options, "shade_strength", "f", &(self->shade_strength)))
return 1;
self->black_color = PyObject_GetAttrString(state->chunk, "black_color");
self->facemasks_py = PyObject_GetAttrString(state->chunk, "facemasks");
// borrowed references, don't need to be decref'd
self->facemasks[0] = PyTuple_GetItem(self->facemasks_py, 0);
self->facemasks[1] = PyTuple_GetItem(self->facemasks_py, 1);
self->facemasks[2] = PyTuple_GetItem(self->facemasks_py, 2);
self->skylight = PyObject_GetAttrString(state->self, "skylight");
self->blocklight = PyObject_GetAttrString(state->self, "blocklight");
self->left_skylight = PyObject_GetAttrString(state->self, "left_skylight");
self->left_blocklight = PyObject_GetAttrString(state->self, "left_blocklight");
self->right_skylight = PyObject_GetAttrString(state->self, "right_skylight");
self->right_blocklight = PyObject_GetAttrString(state->self, "right_blocklight");
self->calculate_darkness = calculate_darkness;
return 0;
}
static void
rendermode_lighting_finish(void *data, RenderState *state) {
RenderModeLighting *self = (RenderModeLighting *)data;
Py_DECREF(self->black_color);
Py_DECREF(self->facemasks_py);
Py_DECREF(self->skylight);
Py_DECREF(self->blocklight);
Py_DECREF(self->left_skylight);
Py_DECREF(self->left_blocklight);
Py_DECREF(self->right_skylight);
Py_DECREF(self->right_blocklight);
/* now chain up */
rendermode_normal.finish(data, state);
}
static int
rendermode_lighting_occluded(void *data, RenderState *state, int x, int y, int z) {
/* no special occlusion here */
return rendermode_normal.occluded(data, state, x, y, z);
}
static int
rendermode_lighting_hidden(void *data, RenderState *state, int x, int y, int z) {
/* no special hiding here */
return rendermode_normal.hidden(data, state, x, y, z);
}
static void
rendermode_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
RenderModeLighting* self;
int x, y, z;
/* first, chain up */
rendermode_normal.draw(data, state, src, mask, mask_light);
self = (RenderModeLighting *)data;
x = state->x, y = state->y, z = state->z;
if ((state->block == 9) || (state->block == 79)) { /* special case for water and ice */
/* looks like we need a new case for lighting, there are
* blocks that are transparent for occlusion calculations and
* need per-face shading if the face is drawn. */
if ((state->block_pdata & 16) == 16) {
do_shading_with_mask(self, state, x, y, z+1, self->facemasks[0]);
}
if ((state->block_pdata & 2) == 2) { /* bottom left */
do_shading_with_mask(self, state, x-1, y, z, self->facemasks[1]);
}
if ((state->block_pdata & 4) == 4) { /* bottom right */
do_shading_with_mask(self, state, x, y+1, z, self->facemasks[2]);
}
/* leaves are transparent for occlusion calculations but they
* per face-shading to look as in game */
} else if (is_transparent(state->block) && (state->block != 18)) {
/* transparent: do shading on whole block */
do_shading_with_mask(self, state, x, y, z, mask_light);
} else {
/* opaque: do per-face shading */
do_shading_with_mask(self, state, x, y, z+1, self->facemasks[0]);
do_shading_with_mask(self, state, x-1, y, z, self->facemasks[1]);
do_shading_with_mask(self, state, x, y+1, z, self->facemasks[2]);
}
}
const RenderModeOption rendermode_lighting_options[] = {
{"shade_strength", "how dark to make the shadows, from 0.0 to 1.0 (default: 1.0)"},
{NULL, NULL}
};
RenderModeInterface rendermode_lighting = {
"lighting", "Lighting",
"draw shadows from the lighting data",
rendermode_lighting_options,
&rendermode_normal,
sizeof(RenderModeLighting),
rendermode_lighting_start,
rendermode_lighting_finish,
rendermode_lighting_occluded,
rendermode_lighting_hidden,
rendermode_lighting_draw,
};