c64: presets

presets/c64/musicplayer.c

@@ -9,6 +9,7 @@ A simple music player.
 #include "sidmacros.h"
 
 #include <cbm_petscii_charmap.h>
+#include <6502.h>
 
 // SID frequency table (PAL version)
 const int note_table_pal[96] = {
@@ -149,7 +150,7 @@ void drawParams() {
   }
 }
 
-void setParamValues() {
+void setSIDRegisters() {
   char i;
   word val;
   char buf[30];
@@ -179,57 +180,61 @@ void setParamValues() {
   music_wavebits = buf[0x04];
 }
 
-void tick(int i) {
-  while (i--) {
-    wait_vblank();
-    play_music();
-  }
+char music_update() {
+  if (!music_ptr) start_music(music1);
+  play_music();
+  return IRQ_NOT_HANDLED;
 }
 
 void handleInput() {
   char key = 0;
   char joy = joy_read(0);
+  if (joy == 0) return;
   if (JOY_UP(joy)) key = 'i';
   if (JOY_DOWN(joy)) key = 'k';
   if (JOY_LEFT(joy)) key = 'j';
   if (JOY_RIGHT(joy)) key = 'l';
-    switch (key) {
-      case 'i': // UP
-        if (currentParam > 0) {
-          --currentParam;
-          drawValue(currentParam+1);
-          drawValue(currentParam);
-          tick(3);
-        }
-        break;
-      case 'k': // DOWN
-        if (currentParam < NPARAMS - 1) {
-          ++currentParam;
-          drawValue(currentParam-1);
-          drawValue(currentParam);
-          tick(3);
-        }
-        break;
-      case 'j': // LEFT
-        if (paramValues[currentParam] > SID_PARAMS[currentParam].low) {
-          paramValues[currentParam]--;
-          drawValue(currentParam);
-          setParamValues();
-        }
-        break;
-      case 'l': // RIGHT
-        if (paramValues[currentParam] < SID_PARAMS[currentParam].high) {
-          paramValues[currentParam]++;
-          drawValue(currentParam);
-          setParamValues();
-        }
-        break;
-    }
+  switch (key) {
+    case 'i': // UP
+      if (currentParam > 0) {
+        --currentParam;
+        drawValue(currentParam+1);
+        drawValue(currentParam);
+      }
+      break;
+    case 'k': // DOWN
+      if (currentParam < NPARAMS - 1) {
+        ++currentParam;
+        drawValue(currentParam-1);
+        drawValue(currentParam);
+      }
+      break;
+    case 'j': // LEFT
+      if (paramValues[currentParam] > SID_PARAMS[currentParam].low) {
+        paramValues[currentParam]--;
+        drawValue(currentParam);
+        setSIDRegisters();
+      }
+      break;
+    case 'l': // RIGHT
+      if (paramValues[currentParam] < SID_PARAMS[currentParam].high) {
+        paramValues[currentParam]++;
+        drawValue(currentParam);
+        setSIDRegisters();
+      }
+      break;
+  }
+  // delay a few frames to slow down movement
+  waitvsync();
+  waitvsync();
+  waitvsync();
 }
 
 void main(void)
 {
   joy_install (joy_static_stddrv);
+  
+  // set initial SID parameters
   paramValues[0] = 15;
   paramValues[1] = 8;
   paramValues[2] = 8;
@@ -237,14 +242,19 @@ void main(void)
   paramValues[4] = 4;
   paramValues[5] = 4;
   paramValues[7] = 1; // pulse
+  setSIDRegisters();
+
+  // draw the UI
   drawParams();
-  setParamValues();
   
+  // set IRQ routine called every frame
+  set_irq(music_update, (void*)0x9f00, 0x100);
+  
+  // main loop to handle UI
   music_ptr = 0;
   while (1) {
+    waitvsync();
     handleInput();
-    if (!music_ptr) start_music(music1);
-    tick(1);
   }
 }
 

presets/c64/siddemo.c

@@ -3,6 +3,7 @@
 //#link "common.c"
 
 #include <tgi.h>
+#include <6502.h>
 
 //#resource "c64-sid.cfg"
 #define CFGFILE c64-sid.cfg
@@ -57,6 +58,11 @@ void show_envelope() {
   if (++sweep == 320) sweep = 0;
 }
 
+char music_update() {
+  sid_update();
+  return IRQ_NOT_HANDLED;
+}
+
 void main(void) {
   // install TGI graphics driver
   tgi_install(tgi_static_stddrv);
@@ -71,6 +77,9 @@ void main(void) {
   // install joystick driver
   joy_install(joy_static_stddrv);
 
+  // set IRQ routine called every frame
+  set_irq(music_update, (void*)0x9f00, 0x100);
+
   while (1) {
     // play sound effect when joystick is moved
     byte joy = joy_read(0);
@@ -81,8 +90,6 @@ void main(void) {
     }
     // sync with frame rate
     waitvsync();
-    // update SID player
-    sid_update();
     // update graphs
     show_envelope();
     show_signal();

presets/c64/test_setirq.c

@@ -0,0 +1,60 @@
+
+#include <conio.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <peekpoke.h>
+#include <string.h>
+#include <c64.h>
+#include <cbm_petscii_charmap.h>
+
+#include "common.h"
+//#link "common.c"
+
+#include <6502.h>
+#include <setjmp.h>
+
+char interrupt_handler() {
+  // only needed if CIA interupts are still active
+  if (!(VIC.irr & VIC_IRR_IRST)) return IRQ_NOT_HANDLED;
+  // change colors so we can see where the IRQ fired
+  VIC.bgcolor0++;
+  VIC.bordercolor++;
+  // reading VIC.rasterline returns the current line
+  // setting it changes the line where the IRQ fires
+  if (VIC.rasterline >= 245) {
+    VIC.rasterline = 40;
+  } else {
+    VIC.rasterline = 245;
+  }
+  // acknowledge VIC raster interrupt (bit 0)
+  VIC.irr = 1;
+  // change colors back to where they were
+  VIC.bgcolor0--;
+  VIC.bordercolor--;
+  return IRQ_HANDLED;
+}
+
+void set_frame_irq(char scanline) {
+  // deactivate CIA interrupts (keyboard, etc)
+  CIA1.icr = 0x7f;
+  // set raster line for interrupt
+  VIC.ctrl1 &= 0x7f; // clear raster line bit 8
+  VIC.rasterline = scanline;
+  // activate VIC raster interrupts
+  VIC.imr = 1;
+}
+
+void main(void) {
+  clrscr();
+  printf("\nHello World!\n");
+  
+  // set interrupt routine
+  set_irq(interrupt_handler, (void*)0x9f00, 0x100);
+  
+  // disable CIA interrupt, activate VIC interrupt
+  set_frame_irq(255);
+
+  while (1) {
+    printf("%d ", VIC.rasterline);
+  }
+}

src/platform/c64.ts

@@ -10,7 +10,8 @@ const C64_PRESETS : Preset[] = [
   {id:'joymove.c', name:'Sprite Movement'},
   {id:'sprite_collision.c', name:'Sprite Collision'},
   {id:'scroll1.c', name:'Scrolling (Single Buffer)'},
-  {id:'test_display_list.c', name:'Display List / Raster IRQ'},
+  {id:'test_setirq.c', name:'Raster Interrupts'},
+  {id:'test_display_list.c', name:'Raster IRQ Library'},
   {id:'scrolling_text.c', name:'Big Scrolling Text'},
   {id:'side_scroller.c', name:'Side-Scrolling Game'},
   {id:'scroll2.c', name:'Scrolling (Double Buffer)'},