First attempt at a copper list

004.copper_bars/Makefile

@@ -0,0 +1,14 @@
+MAKEADF=../tools/makeadf
+FLOPPY=bin/image.adf
+EXTRA=out/copper-list.s
+
+MODULE=copper.s
+
+include ../base.mk
+
+out/copper-list.s: out/copper_gen
+	./out/copper_gen  > out/copper-list.s
+
+out/copper_gen: copper_gen.c
+	gcc copper_gen.c -o out/copper_gen
+

004.copper_bars/README.md

@@ -0,0 +1,3 @@
+Copper bars
+===========
+

004.copper_bars/copper.s

@@ -0,0 +1,58 @@
+	include "../include/registers.i"
+	include "hardware/dmabits.i"
+	include "hardware/intbits.i"
+	
+LVL3_INT_VECTOR		equ $6c
+SCREEN_WIDTH		equ 320
+SCREEN_HEIGHT		equ 256
+SCREEN_WIDTH_BYTES	equ (SCREEN_WIDTH/8)
+SCREEN_BIT_DEPTH	equ 1
+SCREEN_RES		equ 8 	; 8=lo resolution, 4=hi resolution
+RASTER_X_START		equ $81	; Hard coded coordinates from hardware manual
+RASTER_Y_START		equ $2c
+RASTER_X_STOP		equ RASTER_X_START+SCREEN_WIDTH
+RASTER_Y_STOP		equ RASTER_Y_START+SCREEN_HEIGHT
+	
+entry:
+	;; custom chip base globally in a6
+	lea 	CUSTOM,a6
+
+	;; poke bitplane pointers into the copper list
+	lea	bitplane(pc),a0
+	lea 	copperBitPlanePtr(pc),a1
+	move.l	a0,d0
+	move.w	d0,6(a1) 	;BPL1PTL
+	swap	d0
+	move.w	d0,2(a1)	;BPL1PTH
+
+	move.w  #(RASTER_Y_START<<8)|RASTER_X_START,DIWSTRT(a6)
+	move.w	#((RASTER_Y_STOP-256)<<8)|(RASTER_X_STOP-256),DIWSTOP(a6)
+
+	move.w	#(RASTER_X_START/2-SCREEN_RES),DDFSTRT(a6)
+	move.w	#(RASTER_X_START/2-SCREEN_RES)+(8*((SCREEN_WIDTH/16)-1)),DDFSTOP(a6)
+	
+	move.w	#(SCREEN_BIT_DEPTH<<12)|$200,BPLCON0(a6)
+	move.w	#SCREEN_WIDTH_BYTES*SCREEN_BIT_DEPTH-SCREEN_WIDTH_BYTES,BPL1MOD(a6)
+	
+	;; install copper list and enable DMA
+	lea	copper(pc),a0
+	move.l	a0,COP1LC(a6)
+	move.w  COPJMP1(a6),d0
+	move.w	#(DMAF_SETCLR!DMAF_COPPER!DMAF_RASTER!DMAF_MASTER),dmacon(a6)
+
+.mainLoop:
+	bra.b	.mainLoop
+
+copper:
+copperBitPlanePtr:	
+	dc.w	BPL1PTH,0 	; address of the bitplane will be poked once we know it
+	dc.w	BPL1PTL,0
+
+	dc.w    COLOR00,$0000 
+
+	include "out/copper-list.s"
+
+	dc.l	$fffffffe
+
+bitplane:
+	dcb.b   (SCREEN_WIDTH*SCREEN_HEIGHT)/8,$00

004.copper_bars/copper_gen.c

@@ -0,0 +1,69 @@
+// http://krazydad.com/tutorials/makecolors.php
+
+#include <stdio.h>
+#include <math.h>
+
+typedef struct {
+  float r;
+  float g;
+  float b;
+} color;
+
+#define numColors  50
+color colors[numColors];
+
+void
+makeColorGradient()
+{
+  float frequencyr = 02;
+  float frequencyg = 02;
+  float frequencyb = 02;
+  float phase1 = 0.1, phase2 = 0.1, phase3 = 0.1;
+  float center = 0x7;
+  float width = 0x7;
+  float len = numColors;
+
+  for (int i = 0; i < len; ++i) {
+    color* c = &colors[i];
+    c->r = sin(frequencyr*i + phase1) * width + center;
+    c->g = sin(frequencyg*i + phase2) * width + center;
+    c->b = sin(frequencyb*i + phase3) * width + center;
+  }
+}
+
+int 
+main()
+{
+  makeColorGradient();
+
+  int lines = 312;
+  color start = { 0x0, 0x0, 0x0};
+  color end = { 0xF, 0xF, 0xF};
+  color current = {0};
+  int count = lines-0x2c;
+  int from = 0, to = 1;
+  int segment = count/((sizeof(colors)/sizeof(color))-1);
+  
+  for (int i = 0, y = 0; i < count; i++) {
+    if (i != 0 && i % segment == 0) {
+      from++;
+      to++;
+    }
+
+    float distance = (float)((i)%segment)/segment;
+    color* start = &colors[from];
+    color* end = &colors[to];
+    current.r = start->r + ((end->r-start->r)*distance);
+    current.g = start->g + ((end->g-start->g)*distance);
+    current.b = start->b + ((end->b-start->b)*distance);
+
+    if (0x2c+i <= 255) {
+      printf("\tdc.w $%xdf,$fffe\n\tdc.w COLOR00,$%x%x%x\n",0x2c+i, (int)(current.r+0.5), (int)(current.g+0.5), (int)(current.b+0.5));
+    } else {
+      printf("\tdc.w $%xdf,$fffe\n\tdc.w COLOR00,$%x%x%x\n",y++, (int)(current.r+0.5), (int)(current.g+0.5), (int)(current.b+0.5));
+    }
+
+  }
+
+  return 0;
+}

Makefile

@@ -1,4 +1,4 @@
-SUBDIRS=000.trackdisk 001.simple_image 002.sprite_display 003.music
+SUBDIRS=000.trackdisk 001.simple_image 002.sprite_display 003.music 004.copper_bars
 
 .PHONY: subdirs $(SUBDIRS)