/icon.GetPixel()

Content.Tests/DMProject/Tests/Icon/GetPixel.dm

@@ -0,0 +1,33 @@
+/proc/RunTest()
+	var/icon/I = icon('hanoi.dmi')
+	ASSERT(I.GetPixel(5,5) == "#ff0000")
+	var/list/targetx_pixels = list("#e8083f", "#ff0000", "#6aee1d", "#f1b004", "#ffa308", "#ff34e2", "#6aeeff",\
+			"#f4f14d", "#fbed01", "#757121", "#c07760", "#cc7d66", "#c98164", "#5fed26", "#43fc13", "#43fc13", "#43fc13",\
+			"#43fc13",	"#43fc13", "#48fa16", "#bf885e", "#625230", "#4d4b26", "#4c5234", "#09f5f3", "#00ffff", "#00ffff","#f44dfb",\
+			"#2c14ff", "#001bf9", "#00ef58", "#f74d04")
+	var/list/targety_pixels = list("#e8083f","#ff0000","#6bee1a","#1452f2","#e00bfc","#5be5fe","#00ffff","#f2ef4d",\
+			"#6b6622","#4b4b25","#c07760","#cb8065","#57f020","#43fc13","#43fc13","#43fc13","#43fc13","#43fc13",\
+			"#42fc12","#c68c63","#c87c64","#625230","#4c4a26","#f5e921","#2ffef1","#00f9ff","#ee54fc","#ffa04b",\
+			"#f8a225","#3530e4","#00ef58","#f74d04")
+	for(var/x in 1 to 32)
+		ASSERT(I.GetPixel(x,16,"target") == targetx_pixels[x])
+	for(var/y in 1 to 32)
+		ASSERT(I.GetPixel(16,y,"target") == targety_pixels[y])	
+
+	//chose by fair dice roll, guaranteed to be random
+	var/list/random_pixels = list(\
+		list(9, 2, "#ff0000"),\
+		list(31, 8, "#00ef58"),\
+		list(32, 32, "#fe1100"),\
+		list(1, 1, "#d3105d"),\
+		list(2, 13, "#ff0000"),\
+		list(0, 0, null),\
+		list(31, 31, "#00fe28"),\
+		list(-1, 17, null),\
+	)	
+	for(var/list/tuple in random_pixels)
+		ASSERT(I.GetPixel(tuple[1], tuple[2], "target") == tuple[3])
+
+//byond bugs:
+//- invalid iconstate causes error.log to be created but it's empty and no runtime triggers
+//- invalid dir value (ie, 100) causes a hard crash

Content.Tests/DMProject/Tests/Icon/GetPixelBadArgs.dm

@@ -0,0 +1,7 @@
+/proc/RunTest()
+	var/icon/I = icon('hanoi.dmi')
+	ASSERT(I.GetPixel(1,1,"invalid iconstate") == null) //iconstate that doesn't exist
+	ASSERT(I.GetPixel(1,1,"0",dir=EAST) == null) //not a dir in this file
+	ASSERT(I.GetPixel(1,1,"0",dir=100) == null) //nonsense dir
+	ASSERT(I.GetPixel(1,1,"0",frame=-100) == "#ff0000") //frame is clipped at 1
+	ASSERT(I.GetPixel(1,1,"0",frame=100) == null) //there's only 1 frame in the file

DMCompiler/DMStandard/Types/Icon.dm

@@ -16,7 +16,6 @@
 		set opendream_unimplemented = TRUE
 
 	proc/GetPixel(x, y, icon_state, dir = 0, frame = 0, moving = -1)
-		set opendream_unimplemented = TRUE
 
 	proc/Height()
 

OpenDreamRuntime/Procs/Native/DreamProcNative.cs

@@ -177,6 +177,7 @@ public static void SetupNativeProcs(DreamObjectTree objectTree) {
         objectTree.SetNativeProc(objectTree.Icon, DreamProcNativeIcon.NativeProc_Blend);
         objectTree.SetNativeProc(objectTree.Icon, DreamProcNativeIcon.NativeProc_Scale);
         objectTree.SetNativeProc(objectTree.Icon, DreamProcNativeIcon.NativeProc_Turn);
+        objectTree.SetNativeProc(objectTree.Icon, DreamProcNativeIcon.NativeProc_GetPixel);
 
         objectTree.SetNativeProc(objectTree.Savefile, DreamProcNativeSavefile.NativeProc_ExportText);
         objectTree.SetNativeProc(objectTree.Savefile, DreamProcNativeSavefile.NativeProc_Flush);

OpenDreamRuntime/Procs/Native/DreamProcNativeIcon.cs

@@ -1,3 +1,4 @@
+using System.Linq;
 using OpenDreamRuntime.Objects;
 using OpenDreamRuntime.Objects.Types;
 using OpenDreamRuntime.Resources;
@@ -76,6 +77,56 @@
             return DreamValue.Null;
         }
 
+//x, y, icon_state, dir = 0, frame = 0, moving = -1
+        [DreamProc("GetPixel")]
+        [DreamProcParameter("x", Type = DreamValueTypeFlag.Float)]
+        [DreamProcParameter("y", Type = DreamValueTypeFlag.Float)]
+        [DreamProcParameter("icon_state", Type = DreamValueTypeFlag.String, DefaultValue = "")]
+        [DreamProcParameter("dir", Type = DreamValueTypeFlag.Float, DefaultValue = 0)]
+        [DreamProcParameter("frame", Type = DreamValueTypeFlag.Float, DefaultValue = 0)]
+        [DreamProcParameter("moving", Type = DreamValueTypeFlag.Float, DefaultValue = -1)]
+        public static DreamValue NativeProc_GetPixel(NativeProc.Bundle bundle, DreamObject? src, DreamObject? usr) {
+            var srcDreamIcon = (DreamObjectIcon)src!;
+
+            //arg validation
+            int x = bundle.GetArgument(0, "x").MustGetValueAsInteger();
+            int y = bundle.GetArgument(1, "y").MustGetValueAsInteger();
+
+            //outside valid bounds returns null
+            if(x < 1 || x > srcDreamIcon.Icon.Width || y < 1 || y > srcDreamIcon.Icon.Height)
+                return DreamValue.Null;
+
+            string iconState = bundle.GetArgument(2, "icon_state").MustGetValueAsString();
+            if(!srcDreamIcon.Icon.GenerateDMI().DMI.States.TryGetValue(iconState, out var iconStateObject)){
+                if(iconState == string.Empty)
+                    iconStateObject = srcDreamIcon.Icon.GenerateDMI().DMI.States.First().Value;
+                else //invalid icon state causes BYOND to create error.log but it's empty
+                    return DreamValue.Null; //throw new ArgumentException($"Invalid icon_state {iconState} passed to /icon.GetPixel()");
+            }
+
+            AtomDirection dir = (AtomDirection)bundle.GetArgument(3, "dir").MustGetValueAsInteger();
+            if(dir == AtomDirection.None)
+                dir = iconStateObject.Directions.Keys.First();
+            else if(!iconStateObject.Directions.ContainsKey(dir))
+                return DreamValue.Null;
+
+            int frame = Math.Max(1, bundle.GetArgument(4, "frame").MustGetValueAsInteger())-1;
+
+            if (iconStateObject.FrameCount < frame)
+                return DreamValue.Null;
+
+            DreamValue moving = bundle.GetArgument(5, "moving"); // TODO: implement movement states
+
+            var stateDirFrame = iconStateObject.Directions[dir][frame];
+
+            var pixel = srcDreamIcon.Icon.GenerateDMI().Texture[stateDirFrame.X+x-1,stateDirFrame.Y+(srcDreamIcon.Icon.Height-y)];
+            return pixel.A switch {
+                0 => DreamValue.Null,
+                255 => new DreamValue($"#{pixel.R:x2}{pixel.G:x2}{pixel.B:x2}"),
+                _ => new DreamValue($"#{pixel.R:x2}{pixel.G:x2}{pixel.B:x2}{pixel.A:x2}")
+            };
+        }
+
         [DreamProc("Scale")]
         [DreamProcParameter("width", Type = DreamValueTypeFlag.Float)]
         [DreamProcParameter("height", Type = DreamValueTypeFlag.Float)]