vertex colors, with Gouraud shading and all

has yet to be checked for whether it's accurate, optimized, etc...

GPU3D.cpp

@@ -157,6 +157,7 @@ void UpdateClipMatrix();
 
 u32 PolygonMode;
 s16 CurVertex[3];
+u8 VertexColor[3];
 
 Vertex TempVertexBuffer[4];
 u32 VertexNum;
@@ -690,10 +691,9 @@ void SubmitVertex()
     vertextrans->Position[1] = (vertextrans->Position[1] * w_inv) >> 12;
     vertextrans->Position[2] = (vertextrans->Position[2] * w_inv) >> 12;
 
-    // boo
-    vertextrans->Color[0] = 63;
-    vertextrans->Color[1] = 0;
-    vertextrans->Color[2] = 63;
+    vertextrans->Color[0] = VertexColor[0];
+    vertextrans->Color[1] = VertexColor[1];
+    vertextrans->Color[2] = VertexColor[2];
 
     /*printf("vertex trans: %f %f %f %f\n",
            vertextrans->Position[0]/4096.0f,
@@ -1059,6 +1059,18 @@ void ExecuteCommand()
             }
             break;
 
+        case 0x20: // vertex color
+            {
+                u32 c = ExecParams[0];
+                u32 r = c & 0x1F;
+                u32 g = (c >> 5) & 0x1F;
+                u32 b = (c >> 10) & 0x1F;
+                VertexColor[0] = r ? (r<<1)+1 : 0;
+                VertexColor[1] = g ? (g<<1)+1 : 0;
+                VertexColor[2] = b ? (b<<1)+1 : 0;
+            }
+            break;
+
         case 0x21:
             // TODO: more cycles if lights are enabled
             break;

GPU3D_Soft.cpp

@@ -127,6 +127,11 @@ void RenderPolygon(Polygon* polygon)
             //xmax = scrcoords[rcur][0] << 12;
         }
 
+        Vertex* vlcur = polygon->Vertices[lcur];
+        Vertex* vlnext = polygon->Vertices[lnext];
+        Vertex* vrcur = polygon->Vertices[rcur];
+        Vertex* vrnext = polygon->Vertices[rnext];
+
         s32 lfactor, rfactor;
 
         if (scrcoords[lnext][1] == scrcoords[lcur][1])
@@ -139,35 +144,34 @@ void RenderPolygon(Polygon* polygon)
         else
             rfactor = ((y - scrcoords[rcur][1]) << 12) / (scrcoords[rnext][1] - scrcoords[rcur][1]);
 
-        s32 xmin = scrcoords[lcur][0] + (((scrcoords[lnext][0] - scrcoords[lcur][0]) * lfactor) >> 12);
-        s32 xmax = scrcoords[rcur][0] + (((scrcoords[rnext][0] - scrcoords[rcur][0]) * rfactor) >> 12);
+        s32 xl = scrcoords[lcur][0] + (((scrcoords[lnext][0] - scrcoords[lcur][0]) * lfactor) >> 12);
+        s32 xr = scrcoords[rcur][0] + (((scrcoords[rnext][0] - scrcoords[rcur][0]) * rfactor) >> 12);
 
-        for (s32 x = xmin; x <= xmax; x++)
+        u8 rl = vlcur->Color[0] + (((vlnext->Color[0] - vlcur->Color[0]) * lfactor) >> 12);
+        u8 gl = vlcur->Color[1] + (((vlnext->Color[1] - vlcur->Color[1]) * lfactor) >> 12);
+        u8 bl = vlcur->Color[2] + (((vlnext->Color[2] - vlcur->Color[2]) * lfactor) >> 12);
+
+        u8 rr = vrcur->Color[0] + (((vrnext->Color[0] - vrcur->Color[0]) * rfactor) >> 12);
+        u8 gr = vrcur->Color[1] + (((vrnext->Color[1] - vrcur->Color[1]) * rfactor) >> 12);
+        u8 br = vrcur->Color[2] + (((vrnext->Color[2] - vrcur->Color[2]) * rfactor) >> 12);
+
+        s32 xdiv;
+        if (xr == xl)
+            xdiv = 0;
+        else
+            xdiv = 0x1000 / (xr - xl);
+
+        for (s32 x = xl; x <= xr; x++)
         {
+            s32 xfactor = (x - xl) * xdiv;
+
             u8* pixel = &ColorBuffer[((256*y) + x) * 4];
-            pixel[0] = 0;
-            pixel[1] = 63;
-            pixel[2] = 0;
+            pixel[0] = rl + (((rr - rl) * xfactor) >> 12);
+            pixel[1] = gl + (((gr - gl) * xfactor) >> 12);
+            pixel[2] = bl + (((br - bl) * xfactor) >> 12);
             pixel[3] = 31;
         }
     }
-
-    // test
-    /*for (int i = 0; i < nverts; i++)
-    {
-        Vertex* vtx = polygon->Vertices[i];
-
-        s32 scrX = (((vtx->Position[0] + 0x1000) * Viewport[2]) >> 13) + Viewport[0];
-        s32 scrY = (((vtx->Position[1] + 0x1000) * Viewport[3]) >> 13) + Viewport[1];
-        if (scrX > 255) scrX = 255;
-        if (scrY > 191) scrY = 191;
-
-        u8* pixel = &ColorBuffer[((256*scrY) + scrX) * 4];
-        pixel[0] = 0;
-        pixel[1] = 63;
-        pixel[2] = 0;
-        pixel[3] = 31;
-    }*/
 }
 
 void RenderFrame(Vertex* vertices, Polygon* polygons, int npolys)

melonDS.depend

@@ -148,7 +148,7 @@
 
 1486777933 c:\documents\sources\melonds\gpu3d.h
 
-1486777278 source:c:\documents\sources\melonds\gpu3d.cpp
+1486782030 source:c:\documents\sources\melonds\gpu3d.cpp
 	<stdio.h>
 	<string.h>
 	"NDS.h"