netsurf/frontends/amiga/plotters.c

/*
 * Copyright 2008-09, 2012-13 Chris Young <chris@unsatisfactorysoftware.co.uk>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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, see <http://www.gnu.org/licenses/>.
 */

#include "amiga/os3support.h"

#include <proto/exec.h>
#include <proto/intuition.h>
#include <proto/layers.h>
#include <proto/graphics.h>

#include <intuition/intuition.h>
#include <graphics/rpattr.h>
#include <graphics/gfxmacros.h>
#include <graphics/gfxbase.h>

#ifdef __amigaos4__
#include <graphics/blitattr.h>
#include <graphics/composite.h>
#endif

#include <math.h>
#include <assert.h>
#include <stdlib.h>

#include "utils/nsoption.h"
#include "utils/utils.h"
#include "utils/log.h"
#include "netsurf/css.h"
#include "netsurf/mouse.h"
#include "netsurf/window.h"

#include "amiga/plotters.h"
#include "amiga/bitmap.h"
#include "amiga/font.h"
#include "amiga/gui.h"
#include "amiga/memory.h"
#include "amiga/misc.h"
#include "amiga/rtg.h"
#include "amiga/utf8.h"

HOOKF(void, ami_bitmap_tile_hook, struct RastPort *, rp, struct BackFillMessage *);

struct bfbitmap {
	struct BitMap *bm;
	ULONG width;
	ULONG height;
	int offsetx;
	int offsety;
	APTR mask;
	bool palette_mapped;
};

struct ami_plot_pen {
	struct MinNode node;
	ULONG pen;
};

struct bez_point {
	float x;
	float y;
};

struct gui_globals {
	struct BitMap *bm;
	struct RastPort *rp;
	struct Layer_Info *layerinfo;
	APTR areabuf;
	APTR tmprasbuf;
	struct Rectangle rect;
	struct MinList *shared_pens;
	bool managed_pen_list;
	bool palette_mapped;
	ULONG apen;
	ULONG open;
	LONG apen_num;
	LONG open_num;
	int width;  /* size of bm and    */
	int height; /* associated memory */
};

static int init_layers_count = 0;
static APTR pool_pens = NULL;
static bool palette_mapped = true; /* palette-mapped state for the screen */

#ifndef M_PI /* For some reason we don't always get this from math.h */
#define M_PI		3.14159265358979323846
#endif

#define PATT_DOT  0xAAAA
#define PATT_DASH 0xCCCC
#define PATT_LINE 0xFFFF

/* This defines the size of the list for Area* functions.
   25000 = 5000 vectors
  */
#define AREA_SIZE 25000

struct gui_globals *ami_plot_ra_alloc(ULONG width, ULONG height, bool force32bit, bool alloc_pen_list)
{
	/* init shared bitmaps */
 	int depth = 32;
	struct BitMap *friend = NULL;
	struct Screen *scrn = ami_gui_get_screen();

	struct gui_globals *gg = malloc(sizeof(struct gui_globals));

	if(force32bit == false) depth = GetBitMapAttr(scrn->RastPort.BitMap, BMA_DEPTH);
	NSLOG(netsurf, INFO, "Screen depth = %d", depth);

#ifdef __amigaos4__
	if(depth < 16) {
		gg->palette_mapped = true;
		if(force32bit == false) palette_mapped = true;
	} else {
		gg->palette_mapped = false;
		if(force32bit == false) palette_mapped = false;
	}
#else
	/* Friend BitMaps are weird.
	 * For OS4, we shouldn't use a friend BitMap here (see below).
	 * For OS3 AGA, we get no display blitted if we use a friend BitMap,
	 * however on RTG it seems to be a benefit.
	 */
	if(nsoption_bool(friend_bitmap) == true) {
		friend = scrn->RastPort.BitMap;
	} else {
		/* Force friend BitMaps on for obvious RTG screens under OS3.
		 * If we get a bit smarter about this we can lose the user option. */
		if((depth > 8) && (force32bit == false)) friend = scrn->RastPort.BitMap;
	}

	/* OS3 is locked to using palette-mapped display even on RTG.
	 * To change this, comment out the below and build with the similar OS4 lines above.
	 * Various bits of RTG code are OS4-only and OS3 versions will need to be written,
	 * however a brief test reveals a negative performance benefit, so this lock to a
	 * palette-mapped display is most likely permanent.
	 */
#warning OS3 locked to palette-mapped modes
	gg->palette_mapped = true;
	palette_mapped = true;
	if(depth > 8) depth = 8;
#endif

	/* Probably need to fix this next line */
	if(gg->palette_mapped == true) nsoption_set_bool(font_antialiasing, false);

	if(!width) width = nsoption_int(redraw_tile_size_x);
	if(!height) height = nsoption_int(redraw_tile_size_y);
	gg->width = width;
	gg->height = height;

	gg->layerinfo = NewLayerInfo();
	gg->areabuf = malloc(AREA_SIZE);

	/* OS3/AGA requires this to be in chip mem.  RTG would probably rather it wasn't. */
	gg->tmprasbuf = ami_memory_chip_alloc(width * height);

	if(gg->palette_mapped == true) {
		gg->bm = AllocBitMap(width, height, depth, 0, friend);
	} else {
#ifdef __amigaos4__
		/* Screen depth is reported as 24 even when it's actually 32-bit.
		 * We get freezes and other problems on OS4 if we befriend at any
		 * other depths, hence this check.
		 * \todo use friend BitMaps but avoid CompositeTags() at non-32-bit
		 * as that seems to be the cause of the problems.
		 */
		if((depth >= 24) && (force32bit == false)) friend = scrn->RastPort.BitMap;
#endif
		gg->bm = ami_rtg_allocbitmap(width, height, 32, 0, friend, RGBFB_A8R8G8B8);
	}

	if(!gg->bm) amiga_warn_user("NoMemory","");

	gg->rp = malloc(sizeof(struct RastPort));
	if(!gg->rp) amiga_warn_user("NoMemory","");

	InitRastPort(gg->rp);
	gg->rp->BitMap = gg->bm;

	SetDrMd(gg->rp,BGBACKFILL);

	gg->rp->Layer = CreateUpfrontLayer(gg->layerinfo,gg->rp->BitMap,0,0,
					width-1, height-1, LAYERSIMPLE, NULL);

	InstallLayerHook(gg->rp->Layer,LAYERS_NOBACKFILL);

	gg->rp->AreaInfo = malloc(sizeof(struct AreaInfo));
	if((!gg->areabuf) || (!gg->rp->AreaInfo))	amiga_warn_user("NoMemory","");

	InitArea(gg->rp->AreaInfo, gg->areabuf, AREA_SIZE/5);

	gg->rp->TmpRas = malloc(sizeof(struct TmpRas));
	if((!gg->tmprasbuf) || (!gg->rp->TmpRas))	amiga_warn_user("NoMemory","");

	InitTmpRas(gg->rp->TmpRas, gg->tmprasbuf, width*height);

	gg->shared_pens = NULL;
	gg->managed_pen_list = false;

	if(gg->palette_mapped == true) {
		if(pool_pens == NULL) {
			pool_pens = ami_memory_itempool_create(sizeof(struct ami_plot_pen));
		}

		if(alloc_pen_list == true) {
			gg->shared_pens = ami_AllocMinList();
			gg->managed_pen_list = true;
		}
	}

	gg->apen = 0x00000000;
	gg->open = 0x00000000;
	gg->apen_num = -1;
	gg->open_num = -1;

	init_layers_count++;
	NSLOG(netsurf, INFO, "Layer initialised (total: %d)",
	      init_layers_count);

	return gg;
}

void ami_plot_ra_free(struct gui_globals *gg)
{
	init_layers_count--;

	if(init_layers_count < 0) return;

	if((init_layers_count == 0) && (pool_pens != NULL)) {
		ami_memory_itempool_delete(pool_pens);
		pool_pens = NULL;
	}

	if(gg->rp) {
		if(gg->rp->Layer != NULL) DeleteLayer(0, gg->rp->Layer);
		free(gg->rp->TmpRas);
		free(gg->rp->AreaInfo);
		free(gg->rp);
	}

	ami_memory_chip_free(gg->tmprasbuf);
	free(gg->areabuf);
	DisposeLayerInfo(gg->layerinfo);
	if(gg->palette_mapped == false) {
		if(gg->bm) ami_rtg_freebitmap(gg->bm);
	} else {
		if(gg->bm) FreeBitMap(gg->bm);
	}

	if(gg->managed_pen_list == true) {
		ami_plot_release_pens(gg->shared_pens);
		free(gg->shared_pens);
		gg->shared_pens = NULL;
	}

	free(gg);
}

struct RastPort *ami_plot_ra_get_rastport(struct gui_globals *gg)
{
	return gg->rp;
}

struct BitMap *ami_plot_ra_get_bitmap(struct gui_globals *gg)
{
	return gg->bm;
}

void ami_plot_ra_get_size(struct gui_globals *gg, int *width, int *height)
{
	*width = gg->width;
	*height = gg->height;
}

void ami_plot_ra_set_pen_list(struct gui_globals *gg, struct MinList *pen_list)
{
	gg->shared_pens = pen_list;
}

void ami_clearclipreg(struct gui_globals *gg)
{
	struct Region *reg = NULL;
	struct Screen *scrn = ami_gui_get_screen();

	reg = InstallClipRegion(gg->rp->Layer,NULL);
	if(reg) DisposeRegion(reg);

	gg->rect.MinX = 0;
	gg->rect.MinY = 0;
	gg->rect.MaxX = scrn->Width-1;
	gg->rect.MaxY = scrn->Height-1;

	gg->apen = 0x00000000;
	gg->open = 0x00000000;
	gg->apen_num = -1;
	gg->open_num = -1;
}

static ULONG ami_plot_obtain_pen(struct MinList *shared_pens, ULONG colr)
{
	struct ami_plot_pen *node;
	struct Screen *scrn = ami_gui_get_screen();

	LONG pen = ObtainBestPenA(scrn->ViewPort.ColorMap,
			(colr & 0x000000ff) << 24,
			(colr & 0x0000ff00) << 16,
			(colr & 0x00ff0000) << 8,
			NULL);
	
	if(pen == -1) NSLOG(netsurf, INFO,
			    "WARNING: Cannot allocate pen for ABGR:%lx", colr);

	if((shared_pens != NULL) && (pool_pens != NULL)) {
		if((node = (struct ami_plot_pen *)ami_memory_itempool_alloc(pool_pens, sizeof(struct ami_plot_pen)))) {
			node->pen = pen;
			AddTail((struct List *)shared_pens, (struct Node *)node);
		}
	} else {
		/* Immediately release the pen if we can't keep track of it. */
		ReleasePen(scrn->ViewPort.ColorMap, pen);
	}
	return pen;
}

void ami_plot_release_pens(struct MinList *shared_pens)
{
	struct Screen *scrn = ami_gui_get_screen();
	struct ami_plot_pen *node;
	struct ami_plot_pen *nnode;

	if(shared_pens == NULL) return;
	if(IsMinListEmpty(shared_pens)) return;
	node = (struct ami_plot_pen *)GetHead((struct List *)shared_pens);

	do {
		nnode = (struct ami_plot_pen *)GetSucc((struct Node *)node);
		ReleasePen(scrn->ViewPort.ColorMap, node->pen);
		Remove((struct Node *)node);
		ami_memory_itempool_free(pool_pens, node, sizeof(struct ami_plot_pen));
	} while((node = nnode));
}

static void ami_plot_setapen(struct gui_globals *glob, struct RastPort *rp, ULONG colr)
{
	if(glob->apen == colr) return;

#ifdef __amigaos4__
	if(glob->palette_mapped == false) {
		SetRPAttrs(rp, RPTAG_APenColor,
			ns_color_to_nscss(colr),
			TAG_DONE);
	} else
#endif
	{
		LONG pen = ami_plot_obtain_pen(glob->shared_pens, colr);
		if((pen != -1) && (pen != glob->apen_num)) SetAPen(rp, pen);
	}

	glob->apen = colr;
}

static void ami_plot_setopen(struct gui_globals *glob, struct RastPort *rp, ULONG colr)
{
	if(glob->open == colr) return;

#ifdef __amigaos4__
	if(glob->palette_mapped == false) {
		SetRPAttrs(rp, RPTAG_OPenColor,
			ns_color_to_nscss(colr),
			TAG_DONE);
	} else
#endif
	{
		LONG pen = ami_plot_obtain_pen(glob->shared_pens, colr);
		if((pen != -1) && (pen != glob->open_num)) SetOPen(rp, pen);
	}

	glob->open = colr;
}

void ami_plot_clear_bbox(struct RastPort *rp, struct IBox *bbox)
{
	if((bbox == NULL) || (rp == NULL)) return;

	EraseRect(rp, bbox->Left, bbox->Top,
		bbox->Width + bbox->Left, bbox->Height + bbox->Top);
}


static void ami_arc_gfxlib(struct RastPort *rp, int x, int y, int radius, int angle1, int angle2)
{
	float angle1_r = (float)(angle1) * (M_PI / 180.0);
	float angle2_r = (float)(angle2) * (M_PI / 180.0);
	float angle, b, c;
	float step = 0.1; //(angle2_r - angle1_r) / ((angle2_r - angle1_r) * (float)radius);
	int x0, y0, x1, y1;

	x0 = x;
	y0 = y;
	
	b = angle1_r;
	c = angle2_r;
	
	x1 = (int)(cos(b) * (float)radius);
	y1 = (int)(sin(b) * (float)radius);
	Move(rp, x0 + x1, y0 - y1);
		
	for(angle = (b + step); angle <= c; angle += step) {
		x1 = (int)(cos(angle) * (float)radius);
		y1 = (int)(sin(angle) * (float)radius);
		Draw(rp, x0 + x1, y0 - y1);
	}
}

/**
 */
static nserror
ami_bitmap(struct gui_globals *glob, int x, int y, int width, int height, struct bitmap *bitmap)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_bitmap()");
	struct Screen *scrn = ami_gui_get_screen();
	struct BitMap *tbm;

	if (!width || !height) {
		return NSERROR_OK;
	}

	if (((x + width) < glob->rect.MinX) ||
	    ((y + height) < glob->rect.MinY) ||
	    (x > glob->rect.MaxX) ||
	    (y > glob->rect.MaxY)) {
		return NSERROR_OK;
	}

	tbm = ami_bitmap_get_native(bitmap, width, height, glob->palette_mapped, glob->rp->BitMap);
	if (!tbm) {
		return NSERROR_OK;
	}

	NSLOG(plot, DEEPDEBUG, "[ami_plotter] ami_bitmap() got native bitmap");

#ifdef __amigaos4__
	if (__builtin_expect((GfxBase->LibNode.lib_Version >= 53) &&
			     (glob->palette_mapped == false), 1)) {
		uint32 comptype = COMPOSITE_Src_Over_Dest;
		uint32 compflags = COMPFLAG_IgnoreDestAlpha;
		if(amiga_bitmap_get_opaque(bitmap)) {
			compflags |= COMPFLAG_SrcAlphaOverride;
			comptype = COMPOSITE_Src;
		}

		CompositeTags(comptype,tbm,glob->rp->BitMap,
					COMPTAG_Flags, compflags,
					COMPTAG_DestX,glob->rect.MinX,
					COMPTAG_DestY,glob->rect.MinY,
					COMPTAG_DestWidth,glob->rect.MaxX - glob->rect.MinX + 1,
					COMPTAG_DestHeight,glob->rect.MaxY - glob->rect.MinY + 1,
					COMPTAG_SrcWidth,width,
					COMPTAG_SrcHeight,height,
					COMPTAG_OffsetX,x,
					COMPTAG_OffsetY,y,
					COMPTAG_FriendBitMap, scrn->RastPort.BitMap,
					TAG_DONE);
	} else
#endif
	{
		ULONG tag, tag_data, minterm = 0xc0;
		
		if (glob->palette_mapped == false) {
			tag = BLITA_UseSrcAlpha;
			tag_data = !amiga_bitmap_get_opaque(bitmap);
			minterm = 0xc0;
		} else {
			tag = BLITA_MaskPlane;
			if ((tag_data = (ULONG)ami_bitmap_get_mask(bitmap, width, height, tbm)))
				minterm = MINTERM_SRCMASK;
		}
#ifdef __amigaos4__
		BltBitMapTags(BLITA_Width,width,
						BLITA_Height,height,
						BLITA_Source,tbm,
						BLITA_Dest,glob->rp,
						BLITA_DestX,x,
						BLITA_DestY,y,
						BLITA_SrcType,BLITT_BITMAP,
						BLITA_DestType,BLITT_RASTPORT,
						BLITA_Minterm, minterm,
						tag, tag_data,
						TAG_DONE);
#else
		if (tag_data) {
			BltMaskBitMapRastPort(tbm, 0, 0, glob->rp, x, y, width, height, minterm, tag_data);
		} else {
			BltBitMapRastPort(tbm, 0, 0, glob->rp, x, y, width, height, 0xc0);
		}
#endif
	}

	if ((ami_bitmap_is_nativebm(bitmap, tbm) == false)) {
		ami_rtg_freebitmap(tbm);
	}

	return NSERROR_OK;
}


HOOKF(void, ami_bitmap_tile_hook, struct RastPort *, rp, struct BackFillMessage *)
{
	int xf,yf;
	struct bfbitmap *bfbm = (struct bfbitmap *)hook->h_Data;
	struct Screen *scrn = ami_gui_get_screen();

	/* tile down and across to extents  (msg->Bounds.MinX)*/
	for (xf = -bfbm->offsetx; xf < msg->Bounds.MaxX; xf += bfbm->width) {
		for (yf = -bfbm->offsety; yf < msg->Bounds.MaxY; yf += bfbm->height) {
#ifdef __amigaos4__
			if(__builtin_expect((GfxBase->LibNode.lib_Version >= 53) &&
				(bfbm->palette_mapped == false), 1)) {
				CompositeTags(COMPOSITE_Src_Over_Dest, bfbm->bm, rp->BitMap,
					COMPTAG_Flags, COMPFLAG_IgnoreDestAlpha,
					COMPTAG_DestX, msg->Bounds.MinX,
					COMPTAG_DestY, msg->Bounds.MinY,
					COMPTAG_DestWidth, msg->Bounds.MaxX - msg->Bounds.MinX + 1,
					COMPTAG_DestHeight, msg->Bounds.MaxY - msg->Bounds.MinY + 1,
					COMPTAG_SrcWidth, bfbm->width,
					COMPTAG_SrcHeight, bfbm->height,
					COMPTAG_OffsetX, xf,
					COMPTAG_OffsetY, yf,
					COMPTAG_FriendBitMap, scrn->RastPort.BitMap,
					TAG_DONE);
			} else
#endif
			{
				ULONG tag, tag_data, minterm = 0xc0;
		
				if(bfbm->palette_mapped == false) {
					tag = BLITA_UseSrcAlpha;
					tag_data = TRUE;
					minterm = 0xc0;
				} else {
					tag = BLITA_MaskPlane;
					if((tag_data = (ULONG)bfbm->mask))
						minterm = MINTERM_SRCMASK;
				}
#ifdef __amigaos4__
				BltBitMapTags(BLITA_Width, bfbm->width,
					BLITA_Height, bfbm->height,
					BLITA_Source, bfbm->bm,
					BLITA_Dest, rp,
					BLITA_DestX, xf,
					BLITA_DestY, yf,
					BLITA_SrcType, BLITT_BITMAP,
					BLITA_DestType, BLITT_RASTPORT,
					BLITA_Minterm, minterm,
					tag, tag_data,
					TAG_DONE);
#else
				if(tag_data) {
					BltMaskBitMapRastPort(bfbm->bm, 0, 0, rp, xf, yf,
						bfbm->width, bfbm->height, minterm, tag_data);
				} else {
					BltBitMapRastPort(bfbm->bm, 0, 0, rp, xf, yf,
						bfbm->width, bfbm->height, minterm);
				}
#endif
			}			
		}
	}
}

static void ami_bezier(struct bez_point *restrict a, struct bez_point *restrict b,
				struct bez_point *restrict c, struct bez_point *restrict d,
				float t, struct bez_point *restrict p) {
    p->x = pow((1 - t), 3) * a->x + 3 * t * pow((1 -t), 2) * b->x + 3 * (1-t) * pow(t, 2)* c->x + pow (t, 3)* d->x;
    p->y = pow((1 - t), 3) * a->y + 3 * t * pow((1 -t), 2) * b->y + 3 * (1-t) * pow(t, 2)* c->y + pow (t, 3)* d->y;
}


bool ami_plot_screen_is_palettemapped(void)
{
	/* This may not be entirely correct - previously we returned the state of the current BitMap */
	return palette_mapped;
}


/**
 * \brief Sets a clip rectangle for subsequent plot operations.
 *
 * \param ctx The current redraw context.
 * \param clip The rectangle to limit all subsequent plot
 *              operations within.
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_clip(const struct redraw_context *ctx, const struct rect *clip)
{
	struct gui_globals *glob = (struct gui_globals *)ctx->priv;
	struct Region *reg = NULL;

	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_clip()");

	if (glob->rp->Layer) {
		reg = NewRegion();

		glob->rect.MinX = clip->x0;
		glob->rect.MinY = clip->y0;
		glob->rect.MaxX = clip->x1-1;
		glob->rect.MaxY = clip->y1-1;

		OrRectRegion(reg,&glob->rect);

		reg = InstallClipRegion(glob->rp->Layer,reg);

		if(reg) {
			DisposeRegion(reg);
		}
	}

	return NSERROR_OK;
}


/**
 * Plots an arc
 *
 * plot an arc segment around (x,y), anticlockwise from angle1
 *  to angle2. Angles are measured anticlockwise from
 *  horizontal, in degrees.
 *
 * \param ctx The current redraw context.
 * \param style Style controlling the arc plot.
 * \param x The x coordinate of the arc.
 * \param y The y coordinate of the arc.
 * \param radius The radius of the arc.
 * \param angle1 The start angle of the arc.
 * \param angle2 The finish angle of the arc.
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_arc(const struct redraw_context *ctx,
	const plot_style_t *style,
	int x, int y, int radius, int angle1, int angle2)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_arc()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if (angle2 < angle1) {
		angle2 += 360;
	}

	ami_plot_setapen(glob, glob->rp, style->fill_colour);
	ami_arc_gfxlib(glob->rp, x, y, radius, angle1, angle2);

	return NSERROR_OK;
}


/**
 * Plots a circle
 *
 * Plot a circle centered on (x,y), which is optionally filled.
 *
 * \param ctx The current redraw context.
 * \param style Style controlling the circle plot.
 * \param x x coordinate of circle centre.
 * \param y y coordinate of circle centre.
 * \param radius circle radius.
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_disc(const struct redraw_context *ctx,
		const plot_style_t *style,
		int x, int y, int radius)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_disc()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if (style->fill_type != PLOT_OP_TYPE_NONE) {
		ami_plot_setapen(glob, glob->rp, style->fill_colour);
		AreaCircle(glob->rp,x,y,radius);
		AreaEnd(glob->rp);
	}

	if (style->stroke_type != PLOT_OP_TYPE_NONE) {
		ami_plot_setapen(glob, glob->rp, style->stroke_colour);
		DrawEllipse(glob->rp,x,y,radius,radius);
	}

	return NSERROR_OK;
}


/**
 * Plots a line
 *
 * plot a line from (x0,y0) to (x1,y1). Coordinates are at
 *  centre of line width/thickness.
 *
 * \param ctx The current redraw context.
 * \param style Style controlling the line plot.
 * \param line A rectangle defining the line to be drawn
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_line(const struct redraw_context *ctx,
		const plot_style_t *style,
		const struct rect *line)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_line()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	glob->rp->PenWidth = plot_style_fixed_to_int(style->stroke_width);
	glob->rp->PenHeight = plot_style_fixed_to_int(style->stroke_width);

	switch (style->stroke_type) {
		case PLOT_OP_TYPE_SOLID: /**< Solid colour */
		default:
			glob->rp->LinePtrn = PATT_LINE;
		break;

		case PLOT_OP_TYPE_DOT: /**< Doted plot */
			glob->rp->LinePtrn = PATT_DOT;
		break;

		case PLOT_OP_TYPE_DASH: /**< dashed plot */
			glob->rp->LinePtrn = PATT_DASH;
		break;
	}

	ami_plot_setapen(glob, glob->rp, style->stroke_colour);
	Move(glob->rp, line->x0, line->y0);
	Draw(glob->rp, line->x1, line->y1);

	glob->rp->PenWidth = 1;
	glob->rp->PenHeight = 1;
	glob->rp->LinePtrn = PATT_LINE;

	return NSERROR_OK;
}


/**
 * Plots a rectangle.
 *
 * The rectangle can be filled an outline or both controlled
 *  by the plot style The line can be solid, dotted or
 *  dashed. Top left corner at (x0,y0) and rectangle has given
 *  width and height.
 *
 * \param ctx The current redraw context.
 * \param style Style controlling the rectangle plot.
 * \param rect A rectangle defining the line to be drawn
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_rectangle(const struct redraw_context *ctx,
		     const plot_style_t *style,
		     const struct rect *rect)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_rectangle()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if (style->fill_type != PLOT_OP_TYPE_NONE) {
		ami_plot_setapen(glob, glob->rp, style->fill_colour);
		RectFill(glob->rp, rect->x0, rect->y0, rect->x1- 1 , rect->y1 - 1);
	}

	if (style->stroke_type != PLOT_OP_TYPE_NONE) {
		glob->rp->PenWidth = plot_style_fixed_to_int(style->stroke_width);
		glob->rp->PenHeight = plot_style_fixed_to_int(style->stroke_width);

		switch (style->stroke_type) {
			case PLOT_OP_TYPE_SOLID: /**< Solid colour */
			default:
				glob->rp->LinePtrn = PATT_LINE;
			break;

			case PLOT_OP_TYPE_DOT: /**< Dotted plot */
				glob->rp->LinePtrn = PATT_DOT;
			break;

			case PLOT_OP_TYPE_DASH: /**< dashed plot */
				glob->rp->LinePtrn = PATT_DASH;
			break;
 		}

		ami_plot_setapen(glob, glob->rp, style->stroke_colour);
		Move(glob->rp, rect->x0, rect->y0);
		Draw(glob->rp, rect->x1, rect->y0);
		Draw(glob->rp, rect->x1, rect->y1);
		Draw(glob->rp, rect->x0, rect->y1);
		Draw(glob->rp, rect->x0, rect->y0);

		glob->rp->PenWidth = 1;
		glob->rp->PenHeight = 1;
		glob->rp->LinePtrn = PATT_LINE;
	}

	return NSERROR_OK;
}


/**
 * Plot a polygon
 *
 * Plots a filled polygon with straight lines between
 * points. The lines around the edge of the ploygon are not
 * plotted. The polygon is filled with the non-zero winding
 * rule.
 *
 * \param ctx The current redraw context.
 * \param style Style controlling the polygon plot.
 * \param p verticies of polygon
 * \param n number of verticies.
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_polygon(const struct redraw_context *ctx,
		   const plot_style_t *style,
		   const int *p,
		   unsigned int n)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_polygon()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	ami_plot_setapen(glob, glob->rp, style->fill_colour);

	if (AreaMove(glob->rp,p[0],p[1]) == -1) {
		NSLOG(netsurf, INFO, "AreaMove: vector list full");
	}

	for (uint32 k = 1; k < n; k++) {
		if (AreaDraw(glob->rp,p[k*2],p[(k*2)+1]) == -1) {
			NSLOG(netsurf, INFO, "AreaDraw: vector list full");
		}
	}

	if (AreaEnd(glob->rp) == -1) {
		NSLOG(netsurf, INFO, "AreaEnd: error");
	}

	return NSERROR_OK;
}


/**
 * Plots a path.
 *
 * Path plot consisting of cubic Bezier curves. Line and fill colour is
 *  controlled by the plot style.
 *
 * \param ctx The current redraw context.
 * \param pstyle Style controlling the path plot.
 * \param p elements of path
 * \param n nunber of elements on path
 * \param transform A transform to apply to the path.
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_path(const struct redraw_context *ctx,
		const plot_style_t *pstyle,
		const float *p,
		unsigned int n,
		const float transform[6])
{
	unsigned int i;
	struct bez_point start_p = {0, 0}, cur_p = {0, 0}, p_a, p_b, p_c, p_r;

	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_path()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if (n == 0) {
		return NSERROR_OK;
	}

	if (p[0] != PLOTTER_PATH_MOVE) {
		NSLOG(netsurf, INFO, "Path does not start with move");
		return NSERROR_INVALID;
	}

	if (pstyle->fill_colour != NS_TRANSPARENT) {
		ami_plot_setapen(glob, glob->rp, pstyle->fill_colour);
		if (pstyle->stroke_colour != NS_TRANSPARENT) {
			ami_plot_setopen(glob, glob->rp, pstyle->stroke_colour);
		}
	} else {
		if (pstyle->stroke_colour != NS_TRANSPARENT) {
			ami_plot_setapen(glob, glob->rp, pstyle->stroke_colour);
		} else {
			return NSERROR_OK; /* wholly transparent */
		}
	}

	/* Construct path */
	for (i = 0; i < n; ) {
		if (p[i] == PLOTTER_PATH_MOVE) {
			if (pstyle->fill_colour != NS_TRANSPARENT) {
				if (AreaMove(glob->rp, p[i+1], p[i+2]) == -1) {
					NSLOG(netsurf, INFO,
					      "AreaMove: vector list full");
				}
			} else {
				Move(glob->rp, p[i+1], p[i+2]);
			}
			/* Keep track for future Bezier curves/closes etc */
			start_p.x = p[i+1];
			start_p.y = p[i+2];
			cur_p.x = start_p.x;
			cur_p.y = start_p.y;
			i += 3;
		} else if (p[i] == PLOTTER_PATH_CLOSE) {
			if (pstyle->fill_colour != NS_TRANSPARENT) {
				if (AreaEnd(glob->rp) == -1) {
					NSLOG(netsurf, INFO, "AreaEnd: error");
				}
			} else {
				Draw(glob->rp, start_p.x, start_p.y);
			}
			i++;
		} else if (p[i] == PLOTTER_PATH_LINE) {
			if (pstyle->fill_colour != NS_TRANSPARENT) {
				if (AreaDraw(glob->rp, p[i+1], p[i+2]) == -1) {
					NSLOG(netsurf, INFO,
					      "AreaDraw: vector list full");
				}
			} else {
				Draw(glob->rp, p[i+1], p[i+2]);
			}
			cur_p.x = p[i+1];
			cur_p.y = p[i+2];
			i += 3;
		} else if (p[i] == PLOTTER_PATH_BEZIER) {
			p_a.x = p[i+1];
			p_a.y = p[i+2];
			p_b.x = p[i+3];
			p_b.y = p[i+4];
			p_c.x = p[i+5];
			p_c.y = p[i+6];

			for (float t = 0.0; t <= 1.0; t += 0.1) {
				ami_bezier(&cur_p, &p_a, &p_b, &p_c, t, &p_r);
				if (pstyle->fill_colour != NS_TRANSPARENT) {
					if (AreaDraw(glob->rp, p_r.x, p_r.y) == -1) {
						NSLOG(netsurf, INFO,
						      "AreaDraw: vector list full");
					}
				} else {
					Draw(glob->rp, p_r.x, p_r.y);
				}
			}
			cur_p.x = p_c.x;
			cur_p.y = p_c.y;
			i += 7;
		} else {
			NSLOG(netsurf, INFO, "bad path command %f", p[i]);
			/* End path for safety if using Area commands */
			if (pstyle->fill_colour != NS_TRANSPARENT) {
				AreaEnd(glob->rp);
				BNDRYOFF(glob->rp);
			}
			return NSERROR_INVALID;
		}
	}
	if (pstyle->fill_colour != NS_TRANSPARENT) {
		BNDRYOFF(glob->rp);
	}

	return NSERROR_OK;
}


/**
 * Plot a bitmap
 *
 * Tiled plot of a bitmap image. (x,y) gives the top left
 * coordinate of an explicitly placed tile. From this tile the
 * image can repeat in all four directions -- up, down, left
 * and right -- to the extents given by the current clip
 * rectangle.
 *
 * The bitmap_flags say whether to tile in the x and y
 * directions. If not tiling in x or y directions, the single
 * image is plotted. The width and height give the dimensions
 * the image is to be scaled to.
 *
 * \param ctx The current redraw context.
 * \param bitmap The bitmap to plot
 * \param x The x coordinate to plot the bitmap
 * \param y The y coordiante to plot the bitmap
 * \param width The width of area to plot the bitmap into
 * \param height The height of area to plot the bitmap into
 * \param bg the background colour to alpha blend into
 * \param flags the flags controlling the type of plot operation
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_bitmap_tile(const struct redraw_context *ctx,
		struct bitmap *bitmap,
		int x, int y,
		int width,
		int height,
		colour bg,
		bitmap_flags_t flags)
{
	int xf,yf,xm,ym,oy,ox;
	struct BitMap *tbm = NULL;
	struct Hook *bfh = NULL;
	struct bfbitmap bfbm;
	bool repeat_x = (flags & BITMAPF_REPEAT_X);
	bool repeat_y = (flags & BITMAPF_REPEAT_Y);

	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_bitmap_tile()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if ((width == 0) || (height == 0)) {
		return NSERROR_OK;
	}

	if (!(repeat_x || repeat_y)) {
		return ami_bitmap(glob, x, y, width, height, bitmap);
	}

	/* If it is a one pixel transparent image, we are wasting our time */
	if ((amiga_bitmap_get_opaque(bitmap) == false) &&
	    (bitmap_get_width(bitmap) == 1) &&
	    (bitmap_get_height(bitmap) == 1)) {
		return NSERROR_OK;
	}

	tbm = ami_bitmap_get_native(bitmap, width, height, glob->palette_mapped, glob->rp->BitMap);
	if (!tbm) {
		return NSERROR_OK;
	}

	ox = x;
	oy = y;

	/* get left most tile position */
	for (; ox > 0; ox -= width)

	/* get top most tile position */
	for (; oy > 0; oy -= height);

	if (ox < 0) {
		ox = -ox;
	}
	if (oy < 0) {
		oy = -oy;
	}
	if (repeat_x) {
		xf = glob->rect.MaxX;
		xm = glob->rect.MinX;
	} else {
		xf = x + width;
		xm = x;
	}

	if (repeat_y) {
		yf = glob->rect.MaxY;
		ym = glob->rect.MinY;
	} else {
		yf = y + height;
		ym = y;
	}
#ifdef __amigaos4__
	if(amiga_bitmap_get_opaque(bitmap)) {
		bfh = CreateBackFillHook(BFHA_BitMap,tbm,
							BFHA_Width,width,
							BFHA_Height,height,
							BFHA_OffsetX,ox,
							BFHA_OffsetY,oy,
							TAG_DONE);
	} else
#endif
	{
		bfbm.bm = tbm;
		bfbm.width = width;
		bfbm.height = height;
		bfbm.offsetx = ox;
		bfbm.offsety = oy;
		bfbm.mask = ami_bitmap_get_mask(bitmap, width, height, tbm);
		bfbm.palette_mapped = glob->palette_mapped;
		bfh = calloc(1, sizeof(struct Hook));
		bfh->h_Entry = (HOOKFUNC)ami_bitmap_tile_hook;
		bfh->h_SubEntry = 0;
		bfh->h_Data = &bfbm;
	}

	InstallLayerHook(glob->rp->Layer,bfh);
	EraseRect(glob->rp,xm,ym,xf,yf);
	InstallLayerHook(glob->rp->Layer,LAYERS_NOBACKFILL);

#ifdef __amigaos4__
	if (amiga_bitmap_get_opaque(bitmap)) {
		DeleteBackFillHook(bfh);
	} else
#endif
		free(bfh);

	if ((ami_bitmap_is_nativebm(bitmap, tbm) == false)) {
		/**\todo is this logic logical? */
		ami_rtg_freebitmap(tbm);
	}

	return NSERROR_OK;
}


/**
 * Text plotting.
 *
 * \param ctx The current redraw context.
 * \param fstyle plot style for this text
 * \param x x coordinate
 * \param y y coordinate
 * \param text UTF-8 string to plot
 * \param length length of string, in bytes
 * \return NSERROR_OK on success else error code.
 */
static nserror
ami_text(const struct redraw_context *ctx,
		const struct plot_font_style *fstyle,
		int x,
		int y,
		const char *text,
		size_t length)
{
	NSLOG(plot, DEEPDEBUG, "[ami_plotter] Entered ami_text()");

	struct gui_globals *glob = (struct gui_globals *)ctx->priv;

	if (__builtin_expect(ami_nsfont == NULL, 0)) {
		return NSERROR_OK;
	}
	ami_plot_setapen(glob, glob->rp, fstyle->foreground);
	ami_nsfont->text(glob->rp, text, length, fstyle, x, y, nsoption_bool(font_antialiasing));

	return NSERROR_OK;
}


const struct plotter_table amiplot = {
	.rectangle = ami_rectangle,
	.line = ami_line,
	.polygon = ami_polygon,
	.clip = ami_clip,
	.text = ami_text,
	.disc = ami_disc,
	.arc = ami_arc,
	.bitmap = ami_bitmap_tile,
	.path = ami_path,
	.option_knockout = true,
};