💥 improve code quality

GZYangKui · Nov 28, 2023 · 03b1cf1 · 03b1cf1
1 parent a62f93f
commit 03b1cf1
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Showing 2 changed files with 19 additions and 34 deletions.
diff --git a/bin/src/main/java/cn/navclub/nes4j/bin/ppu/PPU.java b/bin/src/main/java/cn/navclub/nes4j/bin/ppu/PPU.java
@@ -1,6 +1,7 @@
 package cn.navclub.nes4j.bin.ppu;
 
 
+import cn.navclub.nes4j.bin.config.NMapper;
 import cn.navclub.nes4j.bin.core.Component;
 import cn.navclub.nes4j.bin.NesConsole;
 import cn.navclub.nes4j.bin.logging.LoggerDelegate;
@@ -161,7 +162,8 @@ public class PPU implements Component {
     //Suppress val or nmi flag
     private boolean suppress;
     private long lastFrameTime;
-
+    private int CpuM2;
+    private int PPU_A12;
 
     public PPU(final NesConsole console, NameMirror mirrors) {
         this.console = console;
@@ -185,6 +187,8 @@ public void reset() {
         this.v = 0;
         this.w = 0;
         this.x = 0;
+        this.CpuM2 = 0;
+        this.PPU_A12 = 0;
         this.oamAddr = 0;
         this.byteBuf = 0;
         this.render.reset();
@@ -200,8 +204,22 @@ public void tick() {
         if (this.lastFrameTime == 0) {
             this.lastFrameTime = System.nanoTime();
         }
+        if (this.PPU_A12 == 0) {
+            this.CpuM2 = this.CpuM2 + 1;
+        }
+        var mapper = this.console.getMapper();
         for (int i = 0; i < 3; i++) {
             this.render.tick();
+            if (mapper.type() == NMapper.MMC3) {
+                var tmp = (this.v >> 12) & 1;
+                if ((this.PPU_A12 ^ 1 ^ tmp) == 0 && this.CpuM2 >= 3) {
+                    mapper.tick();
+                }
+                if ((tmp ^ this.PPU_A12) == 1) {
+                    this.CpuM2 = 0;
+                }
+                this.PPU_A12 = tmp;
+            }
         }
     }
 

diff --git a/bin/src/main/java/cn/navclub/nes4j/bin/ppu/Render.java b/bin/src/main/java/cn/navclub/nes4j/bin/ppu/Render.java
@@ -332,39 +332,6 @@ public void render() {
         if (preLine && this.cycles >= 280 && this.cycles <= 304) {
             this.ppu.v = uint16((this.ppu.v & 0x841f) | (this.ppu.t & 0x7be0));
         }
-
-        var mapper = this.ppu.console.getMapper();
-        if (mapper.type() == NMapper.MMC3 && this.mask.enableRender()) {
-            var ctr = this.ppu.getCtr();
-            //
-            // When using 8x8 sprites, if the BG uses $0000, and the sprites use $1000, the IRQ counter should
-            // decrement on PPU cycle 260, right after the visible part of the target scanline has ended.
-            //
-
-            if (ctr.spriteSize() == 8 && ctr.backgroundNameTable() == 0 && ctr.spritePattern8() == 0x1000 && this.cycles == 260) {
-                mapper.tick();
-            }
-            // When using 8x8 sprites, if the BG uses $1000, and the sprites use $0000, the IRQ counter should decrement
-            // on PPU cycle 324 of the previous scanline (as in, right before the target scanline is about to be drawn).
-            // However, the 2C02's pre-render scanline will decrement the counter twice every other vertical redraw,
-            // so the IRQ will shake one scanline. This is visible in Wario's Woods: with some PPU-CPU reset alignments
-            // the bottom line of the green grass of the play area may flicker black on the rightmost ~48 pixels, due to
-            // an extra count firing the IRQ one line earlier than expected.
-            if (ctr.spriteSize() == 8 && ctr.backgroundNameTable() == 0x1000 && ctr.spritePattern8() == 0 & this.cycles == 324) {
-                if (preLine) mapper.tick();
-                mapper.tick();
-            }
-
-            //
-            // When using 8x16 sprites PPU A12 must be explicitly tracked. The exact time and number of times
-            // the counter is clocked will depend on the specific set of sprites present on every scanline.
-            // Specific combinations of sprites could cause the counter to decrement up to four times,
-            // or the IRQ to be delayed or early by some multiple of 8 pixels. If there are fewer than 8 sprites
-            // on a scanline, the PPU fetches tile $FF ($1FF0-$1FFF) for each leftover sprite and discards
-            // its value. Thus if a game uses 8x16 sprites with its background and sprites from PPU $0000, then
-            // the MMC3 ends up counting each scanline that doesn't use all eight sprites.
-            //
-        }
     }
 
     private void tileMut() {