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https://github.com/aseprite/aseprite.git
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Added algo_polygon() algorithm.
This commit is contained in:
David Capello
parent
031c8d187b
commit
700ab045d2
@ -173,6 +173,7 @@ COMMON_SOURCES = \
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src/modules/tools.cpp \
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src/raster/algo.cpp \
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src/raster/algofill.cpp \
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src/raster/algo_polygon.cpp \
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src/raster/blend.cpp \
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src/raster/brush.cpp \
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src/raster/cel.cpp \
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@ -28,22 +28,22 @@ typedef void (*AlgoLine)(int x1, int y1, int x2, int y2, void *data);
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void algo_dirty(Dirty* dirty, void *data, AlgoHLine proc);
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void algo_line (int x1, int y1, int x2, int y2, void *data, AlgoPixel proc);
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void algo_ellipse (int x1, int y1, int x2, int y2, void *data, AlgoPixel proc);
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void algo_ellipsefill (int x1, int y1, int x2, int y2, void *data, AlgoHLine proc);
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void algo_line(int x1, int y1, int x2, int y2, void *data, AlgoPixel proc);
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void algo_ellipse(int x1, int y1, int x2, int y2, void *data, AlgoPixel proc);
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void algo_ellipsefill(int x1, int y1, int x2, int y2, void *data, AlgoHLine proc);
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void algo_spline (double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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void *data, AlgoLine proc);
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double algo_spline_get_y (double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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double x);
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double algo_spline_get_tan (double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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double in_x);
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void algo_spline(double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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void *data, AlgoLine proc);
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double algo_spline_get_y(double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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double x);
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double algo_spline_get_tan(double x0, double y0, double x1, double y1,
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double x2, double y2, double x3, double y3,
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double in_x);
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void algo_floodfill(Image* image, int x, int y, void* data, AlgoHLine proc);
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void algo_polygon(Image* image, int vertices, const int* points, void* data, AlgoHLine proc);
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#endif
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253
src/raster/algo_polygon.cpp
Normal file
253
src/raster/algo_polygon.cpp
Normal file
@ -0,0 +1,253 @@
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/* ______ ___ ___
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* /\ _ \ /\_ \ /\_ \
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* \ \ \L\ \\//\ \ \//\ \ __ __ _ __ ___
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* \ \ __ \ \ \ \ \ \ \ /'__`\ /'_ `\/\`'__\/ __`\
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* \ \ \/\ \ \_\ \_ \_\ \_/\ __//\ \L\ \ \ \//\ \L\ \
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* \ \_\ \_\/\____\/\____\ \____\ \____ \ \_\\ \____/
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* \/_/\/_/\/____/\/____/\/____/\/___L\ \/_/ \/___/
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* /\____/
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* \_/__/
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*
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* The 2d polygon rasteriser.
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*
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* By Shawn Hargreaves.
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*
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* See readme.txt for copyright information.
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*/
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/* Adapted to ASE by David Capello */
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#include "config.h"
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#include <limits.h>
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#include "allegro.h"
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#include "allegro/internal/aintern.h"
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#include "raster/algo.h"
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#include "raster/image.h"
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/* fill_edge_structure:
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* Polygon helper function: initialises an edge structure for the 2d
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* rasteriser.
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*/
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static void fill_edge_structure(POLYGON_EDGE *edge, AL_CONST int *i1, AL_CONST int *i2)
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{
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if (i2[1] < i1[1]) {
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AL_CONST int *it;
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it = i1;
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i1 = i2;
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i2 = it;
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}
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edge->top = i1[1];
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edge->bottom = i2[1];
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edge->x = (i1[0] << POLYGON_FIX_SHIFT) + (1 << (POLYGON_FIX_SHIFT-1));
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if (i2[1] != i1[1]) {
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edge->dx = ((i2[0] - i1[0]) << POLYGON_FIX_SHIFT) / (i2[1] - i1[1]);
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}
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else {
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edge->dx = ((i2[0] - i1[0]) << POLYGON_FIX_SHIFT) << 1;
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}
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edge->w = MAX(ABS(edge->dx)-1, 0);
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edge->prev = NULL;
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edge->next = NULL;
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if (edge->dx < 0)
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edge->x += edge->dx/2 ;
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}
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/* _add_edge2:
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* Adds an edge structure to a linked list, returning the new head pointer.
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*/
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static POLYGON_EDGE *_add_edge2(POLYGON_EDGE *list, POLYGON_EDGE *edge, int sort_by_x)
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{
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POLYGON_EDGE *pos = list;
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POLYGON_EDGE *prev = NULL;
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if (sort_by_x) {
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while ((pos) && (pos->x < edge->x)) {
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prev = pos;
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pos = pos->next;
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}
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}
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else {
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while ((pos) && (pos->top < edge->top)) {
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prev = pos;
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pos = pos->next;
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}
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}
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edge->next = pos;
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edge->prev = prev;
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if (pos)
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pos->prev = edge;
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if (prev) {
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prev->next = edge;
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return list;
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}
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else
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return edge;
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}
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/* _remove_edge2:
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* Removes an edge structure from a list, returning the new head pointer.
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*/
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static POLYGON_EDGE *_remove_edge2(POLYGON_EDGE *list, POLYGON_EDGE *edge)
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{
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if (edge->next)
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edge->next->prev = edge->prev;
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if (edge->prev) {
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edge->prev->next = edge->next;
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return list;
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}
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else
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return edge->next;
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}
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/* polygon:
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* Draws a filled polygon with an arbitrary number of corners. Pass the
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* number of vertices, then an array containing a series of x, y points
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* (a total of vertices*2 values).
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*/
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void algo_polygon(Image* image, int vertices, const int* points, void* data, AlgoHLine proc)
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{
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int c;
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int top = INT_MAX;
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int bottom = INT_MIN;
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AL_CONST int *i1, *i2;
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POLYGON_EDGE *edge, *next_edge;
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POLYGON_EDGE *active_edges = NULL;
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POLYGON_EDGE *inactive_edges = NULL;
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/* allocate some space and fill the edge table */
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_grow_scratch_mem(sizeof(POLYGON_EDGE) * vertices);
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edge = (POLYGON_EDGE *)_scratch_mem;
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i1 = points;
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i2 = points + (vertices-1) * 2;
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for (c=0; c<vertices; c++) {
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fill_edge_structure(edge, i1, i2);
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if (edge->bottom >= edge->top) {
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if (edge->top < top)
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top = edge->top;
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if (edge->bottom > bottom)
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bottom = edge->bottom;
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inactive_edges = _add_edge2(inactive_edges, edge, FALSE);
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edge++;
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}
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i2 = i1;
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i1 += 2;
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}
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if (bottom >= image->h)
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bottom = image->h-1;
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/* for each scanline in the polygon... */
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for (c=top; c<=bottom; c++) {
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int hid = 0;
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int b1 = 0;
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int e1 = 0;
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int up = 0;
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int draw = 0;
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int e;
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/* check for newly active edges */
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edge = inactive_edges;
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while ((edge) && (edge->top == c)) {
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next_edge = edge->next;
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inactive_edges = _remove_edge2(inactive_edges, edge);
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active_edges = _add_edge2(active_edges, edge, TRUE);
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edge = next_edge;
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}
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/* draw horizontal line segments */
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edge = active_edges;
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while (edge) {
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e = edge->w;
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if (edge->bottom != c) {
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up = 1 - up;
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}
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else {
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e = edge->w >> 1;
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}
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if (edge->top == c) {
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e = edge->w >> 1;
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}
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if ((draw < 1) && (up >= 1)) {
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b1 = (edge->x + e) >> POLYGON_FIX_SHIFT;
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}
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else if (draw >= 1) {
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/* filling the polygon */
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e1 = edge->x >> POLYGON_FIX_SHIFT;
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hid = MAX(hid, b1 + 1);
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if (hid <= e1-1) {
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proc(hid, c, e1-1, data);
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}
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b1 = (edge->x + e) >> POLYGON_FIX_SHIFT;
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}
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/* drawing the edge */
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hid = MAX(hid, edge->x >> POLYGON_FIX_SHIFT);
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if (hid <= ((edge->x + e) >> POLYGON_FIX_SHIFT)) {
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proc(hid, c, (edge->x + e) >> POLYGON_FIX_SHIFT, data);
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hid = 1 + ((edge->x + e) >> POLYGON_FIX_SHIFT);
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}
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edge = edge->next;
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draw = up;
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}
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/* update edges, sorting and removing dead ones */
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edge = active_edges;
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while (edge) {
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next_edge = edge->next;
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if (c >= edge->bottom) {
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active_edges = _remove_edge2(active_edges, edge);
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}
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else {
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edge->x += edge->dx;
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if ((edge->top == c) && (edge->dx > 0)) {
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edge->x -= edge->dx/2;
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}
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if ((edge->bottom == c+1) && (edge->dx < 0)) {
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edge->x -= edge->dx/2;
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}
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while ((edge->prev) && (edge->x < edge->prev->x)) {
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if (edge->next)
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edge->next->prev = edge->prev;
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edge->prev->next = edge->next;
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edge->next = edge->prev;
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edge->prev = edge->prev->prev;
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edge->next->prev = edge;
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if (edge->prev)
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edge->prev->next = edge;
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else
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active_edges = edge;
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}
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}
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edge = next_edge;
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}
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}
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}
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