[DMG] Properly implemented sprite priority

fattard · Jan 20, 2018 · 95f56f6 · 95f56f6
1 parent 9b207a2
commit 95f56f6
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Showing 3 changed files with 48 additions and 9 deletions.
diff --git a/GB_TestResults.md b/GB_TestResults.md
@@ -157,7 +157,7 @@ Notes:
 
 | Test            | Result |
 | --------------- | ------ |
-| sprite priority | :x:    |
+| sprite priority | :+1:   |
 
 ### Mooneye GB misc tests
 

diff --git a/unity3D_proj/Assets/Scripts/Frontend/GB/LCDDisplay.cs b/unity3D_proj/Assets/Scripts/Frontend/GB/LCDDisplay.cs
@@ -48,6 +48,8 @@ public class LCDDisplay : MonoBehaviour
                     Color[] m_LCDColor = new Color[4];
                     Color m_disabledLCDColor;
 
+                    int[] m_bgRowColors = new int[160];
+
 
                     public void SetConfigs(EmuCores.GB.ConfigsGB aConfigs)
                     {
@@ -184,11 +186,13 @@ public void DrawDisplayLine(PPU aPPU, int aScanline)
                                     color |= ((palData >> lo) & 0x1);
 
                                     displayPixels[(i * texWid) + j] = m_LCDColor[color];
+                                    m_bgRowColors[j] = color;
                                 }
 
                                 else
                                 {
                                     displayPixels[(i * texWid) + j] = m_LCDColor[0];
+                                    m_bgRowColors[j] = 0;
                                 }
                             }
 
@@ -213,12 +217,17 @@ public void RenderSprites(PPU aPPU, int aScanline)
                         int i = aScanline;
                         int renderedObj = 0;
 
-                        aOAM.SortByPosX();
+                        aOAM.SortByPosX(i, objHeight);
 
-                        for (int objIdx = 0; objIdx < 40; ++objIdx)
+                        for (int objIdx = 10; objIdx >= 0; --objIdx)
                         {
                             OAM.ObjAttributes obj = aOAM.GetObjAttributesSorted(objIdx);
 
+                            if (obj == null)
+                            {
+                                continue;
+                            }
+
                             int yPos = obj.PosY - 16;
                             int xPos = obj.PosX - 8;
                             int tileIdx = obj.TileIdx;
@@ -264,7 +273,7 @@ public void RenderSprites(PPU aPPU, int aScanline)
                                         // Only appears above BG color0
                                         if (obj.BGPriority == 1)
                                         {
-                                            if (displayPixels[(i * texWid) + pixel] == m_LCDColor[aPPU.BackgroundPalette & 0x03])
+                                            if (m_bgRowColors[pixel] == 0)
                                             {
                                                 displayPixels[(i * texWid) + pixel] = m_LCDColor[color];
                                             }

diff --git a/unity3D_proj/Assets/source/EmuCores/GB/HW/OAM.cs b/unity3D_proj/Assets/source/EmuCores/GB/HW/OAM.cs
@@ -121,16 +121,16 @@ public int CompareTo(object aObj)
                             int v = ((aObj as ObjAttributes).PosX - PosX);
                             if (v > 0)
                             {
-                                return 1;
+                                return -1;
                             }
 
                             else if (v == 0)
                             {
                                 // Same pos, compares idx
-                                return ((aObj as ObjAttributes).ID > ID) ? 1 : -1;
+                                return ((aObj as ObjAttributes).ID > ID) ? -1 : 1;
                             }
 
-                            return -1;
+                            return 1;
                         }
                     }
 
@@ -160,12 +160,42 @@ public ObjAttributes GetObjAttributes(int aIdx)
 
                     public ObjAttributes GetObjAttributesSorted(int aIdx)
                     {
-                        return m_objAttrsSorted[aIdx];
+                        if (aIdx < m_objAttrsSorted.Count)
+                        {
+                            return m_objAttrsSorted[aIdx];
+                        }
+
+                        return null;
                     }
 
 
-                    public void SortByPosX( )
+                    public void SortByPosX(int aScanline, int aObjHeight)
                     {
+                        int totalSelected = 0;
+                        int idx = 0;
+                        m_objAttrsSorted.Clear();
+
+                        // Select the first 10 visible sprites
+                        while (idx < 40)
+                        {
+                            ObjAttributes obj = GetObjAttributes(idx);
+                            int yPos = obj.PosY - 16;
+
+                            if (aScanline >= yPos && aScanline < (yPos + aObjHeight))
+                            {
+                                m_objAttrsSorted.Add(obj);
+                                ++totalSelected;
+
+                                if (totalSelected == 10)
+                                {
+                                    break;
+                                }
+                            }
+
+                            ++idx;
+                        }
+
+                        // Sort by pos X
                         m_objAttrsSorted.Sort();
                     }