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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2012 Blender Foundation.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): Peter Larabell.
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file raskter_mt.c
* \ingroup RASKTER
*/
#include <stdlib.h>
#include "raskter.h"
static int rast_scan_init(struct r_fill_context *ctx, struct poly_vert *verts, int num_verts) {
int x_curr; /* current pixel position in X */
int y_curr; /* current scan line being drawn */
int yp; /* y-pixel's position in frame buffer */
int swixd = 0; /* whether or not edges switched position in X */
int i=0; /* counter */
float *cpxl; /* pixel pointers... */
float *mpxl;
float *spxl;
struct e_status *e_curr; /* edge pointers... */
struct e_status *e_temp;
struct e_status *edgbuf;
struct e_status **edgec;
if(num_verts < 3) {
return(1);
}
if((edgbuf = (struct e_status *)(malloc(sizeof(struct e_status) * num_verts))) == NULL) {
return(0);
}
/* set initial bounds length to 0 */
ctx->bounds_length=0;
/* round 1, count up all the possible spans in the base buffer */
preprocess_all_edges(ctx, verts, num_verts, edgbuf);
/* can happen with a zero area mask */
if (ctx->all_edges == NULL) {
free(edgbuf);
return(1);
}
ctx->possible_edges = NULL;
for(y_curr = ctx->all_edges->ybeg; (ctx->all_edges || ctx->possible_edges); y_curr++) {
for(edgec = &ctx->possible_edges; ctx->all_edges && (ctx->all_edges->ybeg == y_curr);) {
x_curr = ctx->all_edges->x; /* Set current X position. */
for(;;) { /* Start looping edges. Will break when edges run out. */
e_curr = *edgec; /* Set up a current edge pointer. */
if(!e_curr || (e_curr->x >= x_curr)) { /* If we have an no edge, or we need to skip some X-span, */
e_temp = ctx->all_edges->e_next; /* set a temp "next" edge to test. */
*edgec = ctx->all_edges; /* Add this edge to the list to be scanned. */
ctx->all_edges->e_next = e_curr; /* Set up the next edge. */
edgec = &ctx->all_edges->e_next; /* Set our list to the next edge's location in memory. */
ctx->all_edges = e_temp; /* Skip the NULL or bad X edge, set pointer to next edge. */
break; /* Stop looping edges (since we ran out or hit empty X span. */
} else {
edgec = &e_curr->e_next; /* Set the pointer to the edge list the "next" edge. */
}
}
}
yp = y_curr * ctx->rb.sizex;
spxl = ctx->rb.buf + (yp);
for(e_curr = ctx->possible_edges; e_curr; e_curr = e_curr->e_next) {
/* set up xmin and xmax bounds on this scan line */
cpxl = spxl + MAX2(e_curr->x, 0);
e_curr = e_curr->e_next;
mpxl = spxl + MIN2(e_curr->x, ctx->rb.sizex) - 1;
if((y_curr >= 0) && (y_curr < ctx->rb.sizey)) {
ctx->bounds_length++;
}
}
for(edgec = &ctx->possible_edges; (e_curr = *edgec);) {
if(!(--(e_curr->num))) {
*edgec = e_curr->e_next;
} else {
e_curr->x += e_curr->xshift;
if((e_curr->drift += e_curr->drift_inc) > 0) {
e_curr->x += e_curr->xdir;
e_curr->drift -= e_curr->drift_dec;
}
edgec = &e_curr->e_next;
}
}
if(ctx->possible_edges) {
for(edgec = &ctx->possible_edges; (e_curr = *edgec)->e_next; edgec = &(*edgec)->e_next) {
/* if the current edge hits scan line at greater X than the next edge, we need to exchange the edges */
if(e_curr->x > e_curr->e_next->x) {
*edgec = e_curr->e_next;
/* exchange the pointers */
e_temp = e_curr->e_next->e_next;
e_curr->e_next->e_next = e_curr;
e_curr->e_next = e_temp;
/* set flag that we had at least one switch */
swixd = 1;
}
}
/* if we did have a switch, look for more (there will more if there was one) */
for(;;) {
/* reset exchange flag so it's only set if we encounter another one */
swixd = 0;
for(edgec = &ctx->possible_edges; (e_curr = *edgec)->e_next; edgec = &(*edgec)->e_next) {
/* again, if current edge hits scan line at higher X than next edge, exchange the edges and set flag */
if(e_curr->x > e_curr->e_next->x) {
*edgec = e_curr->e_next;
/* exchange the pointers */
e_temp = e_curr->e_next->e_next;
e_curr->e_next->e_next = e_curr;
e_curr->e_next = e_temp;
/* flip the exchanged flag */
swixd = 1;
}
}
/* if we had no exchanges, we're done reshuffling the pointers */
if(!swixd) {
break;
}
}
}
}
/*initialize index buffer and bounds buffers*/
//gets the +1 for dummy at the end
if((ctx->bound_indexes = (int *)(malloc(sizeof(int) * ctx->rb.sizey+1)))==NULL) {
return(0);
}
//gets the +1 for dummy at the start
if((ctx->bounds = (struct scan_line *)(malloc(sizeof(struct scan_line) * ctx->bounds_length+1)))==NULL){
return(0);
}
//init all the indexes to zero (are they already zeroed from malloc???)
for(i=0;i<ctx->rb.sizey+1;i++){
ctx->bound_indexes[i]=0;
}
/* round 2, fill in the full list of bounds, and create indexes to the list... */
preprocess_all_edges(ctx, verts, num_verts, edgbuf);
/* can happen with a zero area mask */
if (ctx->all_edges == NULL) {
free(edgbuf);
return(1);
}
ctx->possible_edges = NULL;
/* restart i as a counter for total span placement in buffer */
i=1;
for(y_curr = ctx->all_edges->ybeg; (ctx->all_edges || ctx->possible_edges); y_curr++) {
for(edgec = &ctx->possible_edges; ctx->all_edges && (ctx->all_edges->ybeg == y_curr);) {
x_curr = ctx->all_edges->x; /* Set current X position. */
for(;;) { /* Start looping edges. Will break when edges run out. */
e_curr = *edgec; /* Set up a current edge pointer. */
if(!e_curr || (e_curr->x >= x_curr)) { /* If we have an no edge, or we need to skip some X-span, */
e_temp = ctx->all_edges->e_next; /* set a temp "next" edge to test. */
*edgec = ctx->all_edges; /* Add this edge to the list to be scanned. */
ctx->all_edges->e_next = e_curr; /* Set up the next edge. */
edgec = &ctx->all_edges->e_next; /* Set our list to the next edge's location in memory. */
ctx->all_edges = e_temp; /* Skip the NULL or bad X edge, set pointer to next edge. */
break; /* Stop looping edges (since we ran out or hit empty X span. */
} else {
edgec = &e_curr->e_next; /* Set the pointer to the edge list the "next" edge. */
}
}
}
yp = y_curr * ctx->rb.sizex;
spxl = ctx->rb.buf + (yp);
if((y_curr >=0) && (y_curr < ctx->rb.sizey)){
ctx->bound_indexes[y_curr]=i;
}
for(e_curr = ctx->possible_edges; e_curr; e_curr = e_curr->e_next) {
/* set up xmin and xmax bounds on this scan line */
cpxl = spxl + MAX2(e_curr->x, 0);
e_curr = e_curr->e_next;
mpxl = spxl + MIN2(e_curr->x, ctx->rb.sizex) - 1;
if((y_curr >= 0) && (y_curr < ctx->rb.sizey)) {
ctx->bounds[i].xstart=cpxl-spxl;
ctx->bounds[i].xend=mpxl-spxl;
i++;
}
}
for(edgec = &ctx->possible_edges; (e_curr = *edgec);) {
if(!(--(e_curr->num))) {
*edgec = e_curr->e_next;
} else {
e_curr->x += e_curr->xshift;
if((e_curr->drift += e_curr->drift_inc) > 0) {
e_curr->x += e_curr->xdir;
e_curr->drift -= e_curr->drift_dec;
}
edgec = &e_curr->e_next;
}
}
if(ctx->possible_edges) {
for(edgec = &ctx->possible_edges; (e_curr = *edgec)->e_next; edgec = &(*edgec)->e_next) {
/* if the current edge hits scan line at greater X than the next edge, we need to exchange the edges */
if(e_curr->x > e_curr->e_next->x) {
*edgec = e_curr->e_next;
/* exchange the pointers */
e_temp = e_curr->e_next->e_next;
e_curr->e_next->e_next = e_curr;
e_curr->e_next = e_temp;
/* set flag that we had at least one switch */
swixd = 1;
}
}
/* if we did have a switch, look for more (there will more if there was one) */
for(;;) {
/* reset exchange flag so it's only set if we encounter another one */
swixd = 0;
for(edgec = &ctx->possible_edges; (e_curr = *edgec)->e_next; edgec = &(*edgec)->e_next) {
/* again, if current edge hits scan line at higher X than next edge, exchange the edges and set flag */
if(e_curr->x > e_curr->e_next->x) {
*edgec = e_curr->e_next;
/* exchange the pointers */
e_temp = e_curr->e_next->e_next;
e_curr->e_next->e_next = e_curr;
e_curr->e_next = e_temp;
/* flip the exchanged flag */
swixd = 1;
}
}
/* if we had no exchanges, we're done reshuffling the pointers */
if(!swixd) {
break;
}
}
}
}
free(edgbuf);
return 1;
}
/* static */ int init_base_data(float(*base_verts)[2], int num_base_verts,
float *buf, int buf_x, int buf_y) {
int i; /* i: Loop counter. */
struct poly_vert *ply; /* ply: Pointer to a list of integer buffer-space vertex coordinates. */
struct r_fill_context ctx = {0};
const float buf_x_f = (float)(buf_x);
const float buf_y_f = (float)(buf_y);
if((ply = (struct poly_vert *)(malloc(sizeof(struct poly_vert) * num_base_verts))) == NULL) {
return(0);
}
ctx.rb.buf = buf; /* Set the output buffer pointer. */
ctx.rb.sizex = buf_x; /* Set the output buffer size in X. (width) */
ctx.rb.sizey = buf_y; /* Set the output buffer size in Y. (height) */
for(i = 0; i < num_base_verts; i++) { /* Loop over all base_verts. */
ply[i].x = (int)((base_verts[i][0] * buf_x_f) + 0.5f); /* Range expand normalized X to integer buffer-space X. */
ply[i].y = (int)((base_verts[i][1] * buf_y_f) + 0.5f); /* Range expand normalized Y to integer buffer-space Y. */
}
i = rast_scan_init(&ctx, ply, num_base_verts); /* Call our rasterizer, passing in the integer coords for each vert. */
free(ply); /* Free the memory allocated for the integer coordinate table. */
return(i); /* Return the value returned by the rasterizer. */
}
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