Blame heliantus/drawing.c

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#include <cairo.h></cairo.h>
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#include "private.h"
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#include "drawing.h"
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static double colorBack[4] = {1, 1, 1, 1};
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static double colorFill[4] = {0.5, 0.5, 0.5, 1};
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static double colorStroke[4] = {0, 0, 0, 1};
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static double lineWidth = 1;
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static double *path;
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static size_t pathSize;
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static size_t pathAllocated;
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static HAlign horAlign = HALIGN_LEFT;
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static VAlign vertAlign = VALIGN_TOP;
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static char *font;
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static double fontSize = 24;
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void background(const char *color)
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	{ heliParseColor(color, colorBack); }
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void fill(const char *color)
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	{ heliParseColor(color, colorFill); }
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void noFill()
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	{ fill("transparent"); }
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void stroke(const char *color)
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	{ heliParseColor(color, colorStroke); }
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void noStroke()
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	{ stroke("transparent"); }
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void strokeWeight(double weight)
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	{ lineWidth = weight; }
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char* rgba(double r, double g, double b, double a) {
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	static char buf[1024];
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	snprintf(buf, sizeof(buf) - 1, "%f %f %f %f", r, g, b, a);
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	return buf;
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}
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char* rgb(double r, double g, double b)
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	{ return rgba(r, g, b, 1); }
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void rect(double x, double y, double width, double height) {
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	resetPath();
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	moveTo(x, y);
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	lineTo(x + width, y);
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	lineTo(x + width, y + height);
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	lineTo(x, y + height);
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	closePath();
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}
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void line(double x1, double y1, double x2, double y2) {
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	resetPath();
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	moveTo(x1, y1);
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	lineTo(x2, y2);
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	strokePath();
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}
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void ellipse(double x, double y, double width, double height) {
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	resetPath();
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	arcPath(x, y, width, height, 0, 360);
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	closePath();
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}
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void point(double x, double y)
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	{ ellipse(x - lineWidth*0.25, y - lineWidth*0.25, lineWidth*0.5, lineWidth*0.5); }
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void arcPath(double x, double y, double w, double h, double start, double stop) {
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	double step = PI/180;
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	start *= PI/180;
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	stop *= PI/180;
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	if (start < stop) { double s = start; stop = start; start = s; }
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	for(double a = start; a < stop; a += step) {
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		double lx = x + cos(a)*w;
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		double ly = y + sin(a)*h;
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		lineTo(lx, ly);
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	}
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}
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void arc(double x, double y, double w, double h, double start, double stop) {
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	resetPath();
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	arcPath(x, y, w, h, start, stop);
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	strokePath();
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}
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void regularPolygon(double x, double y, int sides, double size) {
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	resetPath();
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	size *= 0.5;
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	moveTo(x + size, y);
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	for(int i = 1; i < sides; ++i) {
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		double a = i*PI/sides;
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		lineTo(x + size*cos(a), y + size*sin(a));
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	}
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	closePath();
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}
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void resetPath()
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	{ pathSize = 0; }
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static void endPath(int close, int stroke, int fill) {
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	cairo_t *cr = heliCairo;
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	if (cr && pathSize >= 8) {
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		cairo_save(cr);
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		cairo_move_to(cr, path[0], path[1]);
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		for(int i = 2; i < pathSize; i += 2)
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			cairo_line_to(cr, path[i], path[i+1]);
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		if (close)
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			cairo_close_path(cr);
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		if (fill) {
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			cairo_set_source_rgba(cr, colorFill[0], colorFill[1], colorFill[2], colorFill[3]);
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			if (stroke) cairo_fill_preserve(cr); else cairo_fill(cr);
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		}
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		if (stroke) {
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			cairo_set_line_width(cr, lineWidth);
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			cairo_set_source_rgba(cr, colorStroke[0], colorStroke[1], colorStroke[2], colorStroke[3]);
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			cairo_stroke(cr);
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		}
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		cairo_restore(cr);
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	}
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	resetPath();
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}
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static void pushPathPoint(double x, double y) {
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	if (pathAllocated < pathSize + 2) {
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		pathAllocated += pathAllocated/4 + 32;
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		path = realloc(path, pathAllocated);
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		memset(&path[pathSize], 0, (pathAllocated - pathSize)*sizeof(*path));
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	}
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	path[pathSize++] = x;
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	path[pathSize++] = y;
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}
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void closePath()
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	{ endPath(TRUE, TRUE, TRUE); }
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void strokePath()
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	{ endPath(FALSE, TRUE, FALSE); }
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void lineTo(double x, double y)
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	{ pushPathPoint(x, y); }
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void moveTo(double x, double y)
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	{ resetPath(); lineTo(x, y); }
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void textAlign(HAlign hor, VAlign vert)
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	{ horAlign = hor; vertAlign = vert; }
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void textFont(const char *f)
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	{ free(font); font = heliStringCopy(f); }
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void textSize(double size)
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	{ fontSize = size; }
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void text(const char *text, double x, double y) {
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	resetPath();
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	cairo_t *cr = heliCairo;
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	if (!cr) return;
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	cairo_save(cr);
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	if (font) cairo_select_font_face(cr, font, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL);
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	cairo_set_font_size(cr, fontSize);
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	cairo_text_extents_t extents;
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	cairo_text_extents(cr, text, &extents);
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	double w = extents.x_bearing + extents.width;
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	double h = extents.y_bearing + extents.height;
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	if (horAlign  == HALIGN_CENTER) x -= w*0.5;
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	if (horAlign  == HALIGN_RIGHT ) x -= w;
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	if (vertAlign == VALIGN_CENTER) y -= h*0.5;
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	if (vertAlign == VALIGN_BOTTOM) y -= h;
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	cairo_set_source_rgba(cr, colorStroke[0], colorStroke[1], colorStroke[2], colorStroke[3]);
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	cairo_move_to(cr, x, y);
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	cairo_show_text(cr, text);
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	cairo_restore(cr);
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}
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void heliDrawingPrepareFrame() {
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	resetPath();
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	cairo_t *cr = heliCairo;
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	if (!cr) return;
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	cairo_save(cr);
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	cairo_set_source_rgba(cr, colorBack[0], colorBack[1], colorBack[2], 1);
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	cairo_paint(cr);
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	cairo_restore(cr);
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}
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void heliDrawingFinish() {
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	resetPath();
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	free(path);
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	path = NULL;
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	pathAllocated = 0;
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	free(font);
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	font = NULL;
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}