core: Fix parsing of PixelBender sampleNearest and sampleLinear

This fixes a panic on startup for Sniper Team

core/src/pixel_bender.rs

@@ -212,6 +212,18 @@ pub enum Operation {
     If {
         src: u32,
     },
+    SampleNearest {
+        dst: u16,
+        src: u32,
+        mask: u8,
+        tf: u8,
+    },
+    SampleLinear {
+        dst: u16,
+        src: u32,
+        mask: u8,
+        tf: u8,
+    },
     Else,
     EndIf,
 }
@@ -367,11 +379,30 @@ fn read_op<R: Read>(
                     .push(Operation::LoadFloat { dst, mask, val })
             }
         }
+        Opcode::SampleNearest | Opcode::SampleLinear => {
+            let dst = data.read_u16::<LittleEndian>()?;
+            let mask = data.read_u8()?;
+            let src = read_uint24(data)?;
+            let tf = data.read_u8()?;
+            match opcode {
+                Opcode::SampleNearest => {
+                    shader
+                        .operations
+                        .push(Operation::SampleNearest { dst, mask, src, tf })
+                }
+                Opcode::SampleLinear => {
+                    shader
+                        .operations
+                        .push(Operation::SampleLinear { dst, mask, src, tf })
+                }
+                _ => unreachable!(),
+            }
+        }
         _ => {
             let dst = data.read_u16::<LittleEndian>()?;
             let mask = data.read_u8()?;
             let src = read_uint24(data)?;
-            assert_eq!(data.read_u8()?, 0);
+            assert_eq!(data.read_u8()?, 0, "Unexpected u8 for opcode {opcode:?}");
             shader.operations.push(Operation::Normal {
                 opcode,
                 dst,

core/src/pixel_bender/tests.rs

@@ -183,12 +183,11 @@ fn simple_shader() {
                 src: 19,
                 other: 0,
             },
-            Operation::Normal {
-                opcode: Opcode::SampleNearest,
+            Operation::SampleNearest {
                 dst: 3,
                 mask: 241,
                 src: 16,
-                other: 0,
+                tf: 0,
             },
             Operation::LoadFloat {
                 dst: 4,

tests/tests/swfs/avm2/pixelbender_shaderdata/output.txt

@@ -2,6 +2,8 @@
 description: A shader that does nothing, but does it well. (String)
 name: DoNothing (String)
 namespace: Adobe::Example (String)
+otherSrc: [object ShaderInput] (flash.display::ShaderInput)
+ name: otherSrc (String)
 radius: [object ShaderParameter] (flash.display::ShaderParameter)
  defaultValue: 25 (Array)
   0: 25 (int)

tests/tests/swfs/avm2/pixelbender_shaderdata/shader.pbk

@@ -30,9 +30,12 @@
              defaultValue: 25.0;
          >;
          
+         input image4 otherSrc;
+     
          void evaluatePixel()
          {
              float2 one = (radius / radius) * (size / size);
+             float4 two = sampleLinear(otherSrc, float2(1.0, 2.0));
              dst = sampleNearest(src, outCoord()) + float4(100.0, 0.0, 100.0, 1.0);
          }
      }