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// tiledCanvas.cpp
// this file is part of Context Free
// ---------------------
// Copyright (C) 2006-2016 John Horigan - john@glyphic.com
//
// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
//
// John Horigan can be contacted at john@glyphic.com or at
// John Horigan, 1209 Villa St., Mountain View, CA 94041-1123, USA
//
//
#include "tiledCanvas.h"
#include <cmath>
#include "primShape.h"
#include "bounds.h"
#include <cstdlib>
void tiledCanvas::start(bool clear, const agg::rgba& bk, int w, int h)
{
mWidth = w;
mHeight = h;
mTile->start(clear, bk, w, h);
}
void tiledCanvas::end()
{
mTile->end();
}
void tiledCanvas::primitive(int shape, RGBA8 c, agg::trans_affine tr)
{
if (shape == primShape::fillType) {
mTile->primitive(shape, c, tr);
return;
}
for (auto&& tile: mTileList) {
agg::trans_affine t(tr);
t.tx += tile.x;
t.ty += tile.y;
mTile->primitive(shape, c, t);
}
}
void tiledCanvas::path(RGBA8 c, agg::trans_affine tr, const AST::CommandInfo& attr)
{
for (auto&& tile: mTileList) {
agg::trans_affine t(tr);
t.tx += tile.x;
t.ty += tile.y;
mTile->path(c, t, attr);
}
}
inline bool
tiledCanvas::checkTile(const Bounds& b, const agg::rect_d& canvas, double dx, double dy)
{
mOffset.transform(&dx, &dy);
// If the tile might touch the canvas then record it
agg::rect_d shape(b.mMin_X + dx, b.mMin_Y + dy, b.mMax_X + dx, b.mMax_Y + dy);
bool hit = shape.overlaps(canvas);
if (hit)
mTileList.emplace_back(dx, dy);
return hit;
}
void
tiledCanvas::tileTransform(const Bounds& b)
// Compute a list of tiling offsets for all tiled copies of the shape that overlap
// the canvas. Used for subsequent drawing.
{
double centx = (b.mMin_X + b.mMax_X) * 0.5;
double centy = (b.mMin_Y + b.mMax_Y) * 0.5;
mInvert.transform(¢x, ¢y); // transform to unit square tessellation
centx = std::floor(centx + 0.5); // round to nearest integer
centy = std::floor(centy + 0.5); // round to nearest integer
mTileList.clear();
double dx = -centx, dy = -centy;
mOffset.transform(&dx, &dy);
mTileList.emplace_back(dx, dy);
agg::rect_d canvas(-5, -5, static_cast<double>(mWidth + 9), static_cast<double>(mHeight + 9));
if (mFrieze)
centx = centy = centx + centy; // one will be zero, set them both to the other one
for (int ring = 1; ; ring++) {
bool hit = false;
if (mFrieze) {
// Works for x frieze and y frieze, the other dimension gets zeroed
hit = checkTile(b, canvas, ring - centx, ring - centy);
hit = checkTile(b, canvas, -ring - centx, -ring - centy) || hit;
} else {
for (int pos = -ring; pos < ring; pos++) {
hit = checkTile(b, canvas, pos - centx, -ring - centy) || hit;
hit = checkTile(b, canvas, ring - centx, pos - centy) || hit;
hit = checkTile(b, canvas, -pos - centx, ring - centy) || hit;
hit = checkTile(b, canvas, -ring - centx, -pos - centy) || hit;
}
}
if (!hit) return;
}
}
tiledCanvas::tiledCanvas(Canvas* tile, const agg::trans_affine& tr, CFDG::frieze_t f)
: Canvas(tile->mWidth, tile->mHeight),
mTile(tile),
mTileTransform(tr),
mFrieze(f)
{
}
void tiledCanvas::scale(double scaleFactor)
{
agg::trans_affine_scaling scale(scaleFactor);
// Generate the tiling transform in pixel units
mOffset = mTileTransform * scale;
// The mInvert transform can transform coordinates from the pixel unit tiling
// to the unit square tiling.
if (mFrieze) {
mInvert.reset();
mInvert.sx = mOffset.sx == 0.0 ? 0.0 : 1/mOffset.sx;
mInvert.sy = mOffset.sy == 0.0 ? 0.0 : 1/mOffset.sy;
} else {
mInvert = ~mOffset;
}
}
inline bool
tiledCanvas::checkTileInt(const agg::rect_i& screen,
const agg::trans_affine& screenTessellation,
int x, int y, tileList& points)
{
double dx = x;
double dy = y;
screenTessellation.transform(&dx, &dy);
int px = static_cast<int>(std::floor(dx + 0.5));
int py = static_cast<int>(std::floor(dy + 0.5));
// If the tile is visible then record it
agg::rect_i tile(px, py, px + mWidth - 1, py + mHeight - 1);
bool hit = tile.overlaps(screen);
if (hit)
points.emplace_back(px, py);
return hit;
}
tileList tiledCanvas::getTessellation(int w, int h, int x1, int y1, bool flipY)
{
tileList tessPoints;
// Produce an integer version of mOffset that is centered in the w x h screen
agg::trans_affine tess(mWidth, std::floor(mOffset.shy + 0.5), std::floor(mOffset.shx + 0.5),
flipY ? -mHeight : mHeight, x1, y1);
agg::rect_i screen(0, 0, w - 1, h - 1);
if (mFrieze == CFDG::frieze_x)
tess.sy = 0.0;
if (mFrieze == CFDG::frieze_y)
tess.sx = 0.0;
tessPoints.push_back(agg::point_i(x1, y1)); // always include the center tile
// examine rings of tile units around the center unit until you encounter a
// ring that doesn't have any tile units that intersect the screen. Then stop.
for (int ring = 1; ; ring++) {
bool hit = false;
if (mFrieze) {
hit = checkTileInt(screen, tess, ring, ring, tessPoints);
hit = checkTileInt(screen, tess, -ring, -ring, tessPoints) || hit;
} else {
for (int pos = -ring; pos < ring; pos++) {
hit = checkTileInt(screen, tess, pos, -ring, tessPoints) || hit;
hit = checkTileInt(screen, tess, ring, pos, tessPoints) || hit;
hit = checkTileInt(screen, tess, -pos, ring, tessPoints) || hit;
hit = checkTileInt(screen, tess, -ring, -pos, tessPoints) || hit;
}
}
if (!hit) break;
}
return tessPoints;
}
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