internal/shader: use all functions for vector comparisons

Updates #2186

internal/shader/expr.go

@@ -172,7 +172,7 @@ func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariable
 
 		var t shaderir.Type
 		switch {
-		case op == shaderir.LessThanOp || op == shaderir.LessThanEqualOp || op == shaderir.GreaterThanOp || op == shaderir.GreaterThanEqualOp || op == shaderir.EqualOp || op == shaderir.NotEqualOp || op == shaderir.AndAnd || op == shaderir.OrOr:
+		case op == shaderir.LessThanOp || op == shaderir.LessThanEqualOp || op == shaderir.GreaterThanOp || op == shaderir.GreaterThanEqualOp || op == shaderir.EqualOp || op == shaderir.NotEqualOp || op == shaderir.VectorEqualOp || op == shaderir.VectorNotEqualOp || op == shaderir.AndAnd || op == shaderir.OrOr:
 			// TODO: Check types of the operands.
 			t = shaderir.Type{Main: shaderir.Bool}
 		case lhs[0].Type == shaderir.NumberExpr && rhs[0].Type != shaderir.NumberExpr:

internal/shaderir/hlsl/hlsl.go

@@ -390,7 +390,12 @@ func (c *compileContext) block(p *shaderir.Program, topBlock, block *shaderir.Bl
 			}
 			return fmt.Sprintf("%s(%s)", op, expr(&e.Exprs[0]))
 		case shaderir.Binary:
-			if e.Op == shaderir.MatrixMul {
+			switch e.Op {
+			case shaderir.VectorEqualOp:
+				return fmt.Sprintf("all(%s == %s)", expr(&e.Exprs[0]), expr(&e.Exprs[1]))
+			case shaderir.VectorNotEqualOp:
+				return fmt.Sprintf("!all(%s == %s)", expr(&e.Exprs[0]), expr(&e.Exprs[1]))
+			case shaderir.MatrixMul:
 				// If either is a matrix, use the mul function.
 				// Swap the order of the lhs and the rhs since matrices are row-major in HLSL.
 				return fmt.Sprintf("mul(%s, %s)", expr(&e.Exprs[1]), expr(&e.Exprs[0]))

internal/shaderir/msl/msl.go

@@ -377,6 +377,12 @@ func (c *compileContext) block(p *shaderir.Program, topBlock, block *shaderir.Bl
 			}
 			return fmt.Sprintf("%s(%s)", op, expr(&e.Exprs[0]))
 		case shaderir.Binary:
+			switch e.Op {
+			case shaderir.VectorEqualOp:
+				return fmt.Sprintf("all((%s) == (%s))", expr(&e.Exprs[0]), expr(&e.Exprs[1]))
+			case shaderir.VectorNotEqualOp:
+				return fmt.Sprintf("!all((%s) == (%s))", expr(&e.Exprs[0]), expr(&e.Exprs[1]))
+			}
 			return fmt.Sprintf("(%s) %s (%s)", expr(&e.Exprs[0]), opString(e.Op), expr(&e.Exprs[1]))
 		case shaderir.Selection:
 			return fmt.Sprintf("(%s) ? (%s) : (%s)", expr(&e.Exprs[0]), expr(&e.Exprs[1]), expr(&e.Exprs[2]))

internal/shaderir/program.go

@@ -149,6 +149,8 @@ const (
 	GreaterThanEqualOp
 	EqualOp
 	NotEqualOp
+	VectorEqualOp
+	VectorNotEqualOp
 	And
 	Xor
 	Or
@@ -186,8 +188,14 @@ func OpFromToken(t token.Token, lhs, rhs Type) (Op, bool) {
 	case token.GEQ:
 		return GreaterThanEqualOp, true
 	case token.EQL:
+		if lhs.IsVector() || rhs.IsVector() {
+			return VectorEqualOp, true
+		}
 		return EqualOp, true
 	case token.NEQ:
+		if lhs.IsVector() || rhs.IsVector() {
+			return VectorNotEqualOp, true
+		}
 		return NotEqualOp, true
 	case token.AND:
 		return And, true

internal/shaderir/type.go

@@ -104,6 +104,14 @@ func (t *Type) FloatNum() int {
 	}
 }
 
+func (t *Type) IsVector() bool {
+	switch t.Main {
+	case Vec2, Vec3, Vec4:
+		return true
+	}
+	return false
+}
+
 func (t *Type) IsMatrix() bool {
 	switch t.Main {
 	case Mat2, Mat3, Mat4:

shader_test.go

@@ -1095,3 +1095,37 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		testPixels("DrawTrianglesShader", dst)
 	})
 }
+
+// Issue #2186
+func TestShaderVectorEqual(t *testing.T) {
+	const w, h = 16, 16
+
+	dst := ebiten.NewImage(w, h)
+	s, err := ebiten.NewShader([]byte(`package main
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	a := vec3(1)
+	b := vec3(1)
+	if a == b {
+		return vec4(1, 0, 0, 1)
+	} else {
+		return vec4(0, 1, 0, 1)
+	}
+}
+`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	dst.DrawRectShader(w, h, s, nil)
+
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			got := dst.At(i, j).(color.RGBA)
+			want := color.RGBA{0xff, 0, 0x00, 0xff}
+			if !sameColors(got, want, 2) {
+				t.Errorf("dst.At(%d, %d): got: %v, want: %v", i, j, got, want)
+			}
+		}
+	}
+}