From 37da2899f40661e3e9631e497da8dc59b971cbd0 Mon Sep 17 00:00:00 2001
From: "Charles.Forsyth" <devnull@localhost>
Date: Fri, 22 Dec 2006 17:07:39 +0000
Subject: 20060303a

---
 appl/lib/print/scaler.b | 186 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 186 insertions(+)
 create mode 100644 appl/lib/print/scaler.b

(limited to 'appl/lib/print/scaler.b')

diff --git a/appl/lib/print/scaler.b b/appl/lib/print/scaler.b
new file mode 100644
index 00000000..fd33b591
--- /dev/null
+++ b/appl/lib/print/scaler.b
@@ -0,0 +1,186 @@
+implement Scaler;
+
+include "sys.m";
+	sys: Sys;
+include "draw.m";
+include "print.m";
+include "scaler.m";
+
+DEBUG := 0;
+
+# Scaler initialisation
+
+init(debug: int, WidthInPixels, ScaleFactorMultiplier, ScaleFactorDivisor: int): ref RESSYNSTRUCT
+{
+	DEBUG = debug;
+	ScaleFactor := real ScaleFactorMultiplier / real ScaleFactorDivisor;
+	ScaleBound := int ScaleFactor;
+	if  (ScaleFactor > real ScaleBound) ScaleBound++;
+	ResSynStruct := ref RESSYNSTRUCT (
+					WidthInPixels+2,	# add 2 for edges
+					ScaleFactorMultiplier,
+					ScaleFactorDivisor,
+					ScaleFactor,
+					int ((real WidthInPixels / real ScaleFactorDivisor))*ScaleFactorMultiplier + 1,
+					ScaleFactorMultiplier != ScaleFactorDivisor,
+					ScaleFactor < 2.0,
+					(ScaleFactorMultiplier * 256 / ScaleFactorDivisor)
+										  -  ((ScaleFactorMultiplier/ScaleFactorDivisor) * 256),
+					0,
+					0,
+					array[NUMBER_RASTERS] of array of int,
+					array[ScaleBound] of array of int,
+					0,
+					0
+				);
+	if (ResSynStruct.ScaleFactor > real ScaleBound) ScaleBound++;
+	for (i:=0; i<len ResSynStruct.Buffer; i++) ResSynStruct.Buffer[i] = array[WidthInPixels*NUMBER_RASTERS] of int;
+	for (i=0; i<len ResSynStruct.oBuffer; i++) ResSynStruct.oBuffer[i] = array[ResSynStruct.iOutputWidth] of int;
+	return ResSynStruct;
+}
+
+
+# Input a raster line to the scaler
+
+rasterin(rs: ref RESSYNSTRUCT, inraster: array of int)
+{
+	if (!rs.scaling) {		# Just copy to output buffer
+		if (inraster == nil) return;
+		rs.oBuffer[0] = inraster;
+		rs.nready = 1;
+		rs.ndelivered = 0;
+		return;
+	}
+
+	if (rs.ReplicateOnly) {	# for scaling between 1 and 2
+#		for (i:=0; i<len inraster; i++) rs.oBuffer[0][i] = inraster[i];
+		rs.oBuffer[0][:] = inraster[0:];
+		create_out(rs, 1);
+		return;
+	}
+
+	if (rs.RastersinBuffer == 0) {	# First time through
+		if (inraster == nil) return;
+		for (i:=0; i<2; i++) {
+			rs.Buffer[i][0] = inraster[0];
+#			for (j:=1; j<rs.Width-1; j++) rs.Buffer[i][j] = inraster[j-1];
+			rs.Buffer[i][1:] = inraster[0:rs.Width-2];
+			rs.Buffer[i][rs.Width-1] = inraster[rs.Width-3];
+		}
+		rs.RastersinBuffer = 2;
+		return;
+	}
+
+	if (rs.RastersinBuffer == 2) {	# Just two buffers in so far
+		if (inraster != nil) {
+			i := 2;
+			rs.Buffer[i][0] = inraster[0];
+#			for (j:=1; j<rs.Width-1; j++) rs.Buffer[i][j] = inraster[j-1];
+			rs.Buffer[i][1:] = inraster[0:rs.Width-2];
+			rs.Buffer[i][rs.Width-1] = inraster[rs.Width-3];
+			rs.RastersinBuffer = 3;
+		} else {	# nil means end of image
+			rez_synth(rs, rs.oBuffer[0], rs.oBuffer[1]);
+			create_out(rs, 0);
+		}
+		return;
+	}
+	if (rs.RastersinBuffer == 3) {	# All three buffers are full
+		(rs.Buffer[0], rs.Buffer[1], rs.Buffer[2]) = (rs.Buffer[1], rs.Buffer[2], rs.Buffer[0]);
+		if (inraster != nil) {
+			i := 2;
+			rs.Buffer[i][0] = inraster[0];
+#			for (j:=1; j<rs.Width-1; j++) rs.Buffer[i][j] = inraster[j-1];
+			rs.Buffer[i][1:] = inraster[0:rs.Width-2];
+			rs.Buffer[i][rs.Width-1] = inraster[rs.Width-3];
+		} else {	# nil means end of image
+#			for (j:=0; j<len rs.Buffer[1]; j++) rs.Buffer[2][j] = rs.Buffer[1][j];
+			rs.Buffer[2][:] = rs.Buffer[1];
+			rs.RastersinBuffer = 0;
+
+		}
+		rez_synth(rs, rs.oBuffer[0], rs.oBuffer[1]);
+		create_out(rs, 0);
+	}
+
+}
+
+
+# Get a raster output line from the scaler
+
+rasterout(rs: ref RESSYNSTRUCT): array of int
+{
+	if (rs.nready-- > 0) {
+		return rs.oBuffer[rs.ndelivered++][:rs.iOutputWidth-1];
+	} else return nil;
+}
+
+
+
+# Create output raster
+
+create_out(rs: ref RESSYNSTRUCT, simple: int)
+{
+	factor: int;
+	if (simple) factor = 1;
+	else factor = 2;
+
+	out_width := (rs.Width-2) * rs.ScaleFactorMultiplier / rs.ScaleFactorDivisor;
+	number_out := rs.ScaleFactorMultiplier / rs.ScaleFactorDivisor; 
+	if (number_out == 2 && !(rs.ScaleFactorMultiplier % rs.ScaleFactorDivisor) ) {
+		rs.nready = 2;
+		rs.ndelivered = 0;
+		return;
+	}
+
+	if (rs.ScaleFactorMultiplier % rs.ScaleFactorDivisor)
+	{
+		rs.Remainder = rs.Remainder + rs.Repeat;  
+
+		if (rs.Remainder >= 256)	# send extra raster
+		{
+			number_out++;
+			rs.Remainder = rs.Remainder - 256; 
+		}
+	}
+	# set up pointers into the output buffer
+	output_raster := array[number_out] of array of int;
+	output_raster[:] = rs.oBuffer[0:number_out];
+
+	ScaleFactorMultiplier := rs.ScaleFactorMultiplier;
+	ScaleFactorDivisor := rs.ScaleFactorDivisor;
+	sf := factor * ScaleFactorDivisor;
+
+	# Convert the input data by starting at the bottom right hand corner and move left + up
+	for (i:=(number_out-1); i>=0; i--) {
+		y_index := i*sf/ScaleFactorMultiplier;
+		orast_i := output_raster[i];
+		orast_y := output_raster[y_index];
+		for (lx := out_width-1; lx>=0; --lx) {
+			x_index := lx*sf/ScaleFactorMultiplier;
+			orast_i[lx] = orast_y[x_index];
+		}
+	}
+
+	rs.nready = number_out;
+	rs.ndelivered = 0;
+	return;
+}
+
+
+# Synthesise raster line
+
+rez_synth(rs: ref RESSYNSTRUCT, output_raster0, output_raster1: array of int)
+{
+
+	i := 1;
+	Buffer := rs.Buffer[i];
+	h_offset := 0;
+	for (j:=1; j<rs.Width-1; j++) {
+		rgb := Buffer[j];
+		output_raster0[h_offset] = rgb;
+		output_raster1[h_offset++] = rgb;
+		output_raster0[h_offset] = rgb;
+		output_raster1[h_offset++] = rgb;
+	}
+}
-- 
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