wh-engine/wh-engine/render/shader.lisp

495 lines
23 KiB
Common Lisp

;;;; wh-engine/render/shader.lisp
;;;; Lisp class for holding & handling shaders.
(in-package wh-engine/render)
(defun replace-xref-vars (forms vars replace-fun)
(loop for elt on forms
for form = (car elt)
if (symbolp form)
do (let ((var-entry (find form vars :key #'car)))
(when var-entry
(rplaca elt (funcall replace-fun var-entry))))
else if (consp form)
do (replace-xref-vars (cdr form) vars replace-fun)))
(defvar *vert-builtins* '((*vertex-id* . "gl_VertexID")
(*instance-id* . "gl_InstanceID")
(*draw-id* . "gl_DrawID")
(*base-vertex* . "gl_BaseVertex")
(*base-instance* . "gl_BaseInstance")
;; out
(*position* . "gl_Position")
(*point-size* . "gl_PointSize")
(*clip-distance* . "gl_ClipDistance")))
(defvar *frag-builtins* '((*frag-coord* . "gl_FragCoord")
(*front-facing* . "gl_FrontFacing")
(*point-coord* . "gl_PointCoord")
(*sample-id* . "gl_SampleID")
(*sample-position* . "gl_SamplePosition")
(*sample-mask-in* . "gl_SampleMaskIn")
(*clip-distance* . "gl_ClipDistance")
(*primitive-id* . "gl_PrimitiveID")
(*layer* . "gl_Layer")
(*viewport-index* . "gl_ViewportIndex")
;; out
(*frag-depth* . "gl_FragDepth")
(*sample-mask* . "gl_SampleMask")))
(defvar *infix-ops* '((+ "+" t)
(- "-" t)
(* "*" t)
(/ "/" t)
(mod "%" t)
(= "==" t)
(eq "==" nil)
(eql "==" nil)
(equal "==" nil)
(/= "!=" nil)
(< "<" t)
(> ">" t)
(<= "<=" t)
(>= ">=" t)
(<< "<<" nil)
(>> ">>" nil)
(ash "<<" nil)
(logand "&" t)
(logior "|" t)
(logxor "^" t)
(and "&&" t)
(or "||" t)))
(defvar *types* '((:void . "void")
(:bool . "bool")
(:int . "int")
(:uint . "uint")
(:float . "float")
(:double . "double")
(:vec2 . "vec2")
(:vec3 . "vec3")
(:vec4 . "vec4")
(:double-vec2 . "dvec2")
(:double-vec3 . "dvec3")
(:double-vec4 . "dvec4")
(:bool-vec2 . "bvec2")
(:bool-vec3 . "bvec3")
(:bool-vec4 . "bvec4")
(:int-vec2 . "ivec2")
(:int-vec3 . "ivec3")
(:int-vec4 . "ivec4")
(:uint-vec2 . "uvec2")
(:uint-vec3 . "uvec3")
(:uint-vec4 . "uvec4")
(:mat2 . "mat2")
(:mat3 . "mat3")
(:mat4 . "mat4")
(:sampler-1d . "sampler1D")
(:depth-sampler-1d . "sampler1DShadow")
(:array-sampler-1d . "sampler1DArray")
(:depth-array-sampler-1d . "sampler1DArrayShadow")
(:sampler-2d . "sampler2D")
(:depth-sampler-2d . "sampler2DShadow")
(:array-sampler-2d . "sampler2DArray")
(:depth-array-sampler-2d . "sampler2DArrayShadow")
(:multisampler-2d . "sampler2DMS")
(:array-multisampler-2d . "sampler2DMSArray")
(:rect-sampler-2d . "sampler2DRect")
(:depth-rect-sampler-2d . "sampler2DRectShadow")
(:sampler-3d . "sampler3D")
(:cube-sampler . "samplerCube")
(:depth-cube-sampler . "samplerCubeShadow")
(:array-cube-sampler . "samplerCubeArray")
(:depth-array-cube-sampler . "samplerCubeArrayShadow")
(:buffer-sampler . "samplerBuffer")))
(defvar *shader-funs* '((bool . "bool")
(int . "int")
(uint . "uint")
(float . "float")
(double . "double")
(vec2 . "vec2")
(vec3 . "vec3")
(vec4 . "vec4")
(radians . "radians")
(degrees . "degrees")
(sin . "sin")
(cos . "cos")
(tan . "tan")
(asin . "asin")
(acos . "acos")
(atan . "atan")
(sinh . "sinh")
(cosh . "cosh")
(tanh . "tanh")
(asinh . "asinh")
(acosh . "acosh")
(atanh . "atanh")
(expt . "pow")
(exp . "exp")
(log . "log")
(sqrt . "sqrt")
(abs . "abs")
(signum . "sign")
(floor . "floor")
(ffloor . "floor")
(truncate . "trunc")
(ftruncate . "trunc")
(round . "round")
(fround . "round")
(ceiling . "ceil")
(fceiling . "ceil")
(mod . "mod")
(min . "min")
(max . "max")
(linear-blend . "mix")
(step . "step")
(smooth-step . "smoothstep")
(float-nan-p . "isnan")
(float-infinity-p . "isinf")
(vlength . "length")
(vdistance . "distance")
(v. . "dot")
(vc . "cross")
(v2norm . "normalize")
(vforward . "faceforward")
(vreflect . "reflect")
(vrefract . "refract")
(mtranspose . "transpose")
(mdet . "determinant")
(minv . "inverse")
(v< . "lessThan")
(v<= . "lessThanEqual")
(v> . "greaterThan")
(v>= . "greaterThanEqual")
(v= . "equal")
(v/= . "notEqual")
(texture-size . "textureSize")
(texture-lod . "textureQueryLod")
(texture-levels . "textureQueryLevels")
(texture-samples . "textureSamples")
(sample-texture . "texture")
(sample-texture-raw . "texelFetch")))
(defun swizzlep (sym)
(let ((sym-str (string-downcase (symbol-name sym))))
(and (char= (char sym-str 0) #\v)
(loop for c across (subseq sym-str 1)
always (member c '(#\x #\y #\z #\w) :test #'char=))
(subseq sym-str 1))))
(defun conv-shader-type (type)
(or (cdr (assoc type *types*))
(error "Invalid type specifier: ~S" type)))
(defvar *shader-var-suffix* 0)
(defun conv-shader-var (sym &optional gen-suffix)
(concatenate 'string
(substitute-if-not #\_ (lambda (c) (or (alpha-char-p c) (digit-char-p c)))
(remove #\- (string-downcase (string-capitalize (symbol-name sym)) :end 1)))
(if gen-suffix
(write-to-string (incf *shader-var-suffix*))
"")))
(defun conv-shader-form (form vars funs)
(flet ((conv-form (x) (conv-shader-form x vars funs)))
(etypecase form
(cons
(let* ((sym (car form))
(args (cdr form))
(infix-op (assoc sym *infix-ops*))
(swizzle (swizzlep sym)))
(cond
(infix-op
;; special case for -, which is also a unary op
(if (and (eq sym '-) (= (length args) 1))
(format nil "(-~A)"
(conv-form (first args)))
(progn
(unless (or (= (length args) 2) (and (nth 2 infix-op) (> (length args) 2)))
(error "Invalid # of args for shader infix-op: ~S" infix-op))
;; don't wanna repeat this a bajillion times, so just splice the
;; GLSL version of the operator into the format control string
(format nil (concatenate 'string "(~{~A~^ " (nth 1 infix-op) " ~})")
(loop for x in args collect (conv-form x))))))
;; the unary operators ! and ~
((member sym '(not lognot))
(unless (= (length args) 1)
(error "Invalid # of args for shader unary-op: ~S" sym))
(format nil (if (eq sym 'not) "(!~A)" "(~~~A)")
(conv-form (first args))))
;; hijack the (exprA, exprB, ...) to allow multi-setf
((eq sym 'setf)
(unless (= (mod (length args) 2) 0)
(error "Invalid # of args for shader setf"))
(format nil "(~{~A = ~A~^, ~})"
(loop for x in args collect (conv-form x))))
((eq sym 'nth)
(unless (= (length args) 2)
(error "Invalid # of args for shader nth"))
(format nil "~A[~A]"
(conv-form (second args))
(conv-form (first args))))
((eq sym 'aref)
(unless (>= (length args) 2)
(error "Invalid # of args for shader aref"))
(format nil "~A~{[~A]~}"
(conv-form (first args))
(loop for x in (rest args) collect (conv-form x))))
;; non-statement (if) is the ternary operator
((eq sym 'if)
(unless (= (length args) 3)
(error "Invalid # of args for shader if"))
(format nil "(~A ? ~A : ~A)"
(conv-form (first args))
(conv-form (second args))
(conv-form (third args))))
;; WHY IS THIS A FUNCTION HISS
((eq sym 'length)
(unless (= (length args) 1)
(error "Invalid # of args for shader length"))
(format nil "~A.length()"
(conv-form (first args))))
;; apparently you can do this, (exprA, exprB) is non-statement progn
;; thanks C
((eq sym 'progn)
(unless (>= (length args) 1)
(error "Invalid # of args for shader progn"))
(format nil "(~{~A~^, ~})"
(loop for x in args collect (conv-form x))))
(swizzle
(unless (= (length args) 1)
(error "Invalid # of args for shader swizzle"))
(format nil "~A.~A"
(conv-form (first args))
swizzle))
(t
(format nil "~A(~{~A~^, ~})"
(or (cdr (assoc sym funs)) (error "Invalid shader fun: ~S" sym))
(loop for x in args collect (conv-form x)))))))
(boolean (if form "true" "false"))
(symbol (or (cdr (assoc form vars)) (error "Invalid shader var: ~S" form)))
(integer (format nil "~D" form))
(float (format nil "~F" form)))))
(defun conv-shader-stmt (stmt vars funs returnp)
(labels ((conv-form (x) (conv-shader-form x vars funs))
(conv-stmt (x r) (conv-shader-stmt x vars funs r))
(loop-conv-stmts (list r)
(loop for x on list
collect (conv-stmt (car x) (and r (not (cdr x)))))))
(let* ((sym (when (consp stmt) (car stmt)))
(args (when (consp stmt) (cdr stmt))))
(case sym
((progn)
(format nil "{~%~{~A~}}~%"
(loop-conv-stmts args returnp)))
((if)
(unless (<= 2 (length args) 3)
(error "Invalid # of args for shader if"))
(format nil "if (~A) ~{~%~A~^else~}"
(conv-form (first args))
(loop-conv-stmts (rest args) returnp)))
;; handle both forms in one case clause
((when unless)
(unless (>= (length args) 2)
(error "Invalid # of args for shader when/unless"))
(format nil "if (~:[~;!(~]~A~2:*~:[~;)~]~1*) {~%~{~A~}}~%"
(eq sym 'unless)
(conv-form (first args))
(loop-conv-stmts (rest args) returnp)))
((cond)
(unless (>= (length args) 1)
(error "Invalid # of args for shader cond"))
(format nil "~{~:[if (~A) ~;~1*~]{~%~{~A~}}~^ else ~}~%"
(loop for clause in args
nconc (list (eq (first clause) t)
(conv-form (first clause))
(loop-conv-stmts (rest clause) returnp)))))
((case)
(unless (>= (length args) 2)
(error "Invalid # of args for shader case"))
(format nil "switch (~A) {~%~{~:[~{case ~A:~%~}~;default:~%~1*~]~{~A~}break;~%~}}~%"
(conv-form (first args))
(loop for clause in (rest args)
nconc (list (eq (car clause) t)
(if (listp (car clause))
(loop for x in (car clause) collect (conv-form x))
(list (conv-form (car clause))))
(loop-conv-stmts (cdr clause) returnp)))))
((return)
(unless (<= 0 (length args) 1)
(error "Invalid # of args for shader return"))
(format nil "return~:[~; ~A~];~%"
args
(and args (conv-form (first args)))))
((break continue discard)
(when args
(error "Invalid # of args for shader break"))
(format nil "~(~A~);~%" sym))
((while)
(unless (>= (length args) 1)
(error "Invalid # of args for shader while"))
(format nil "while (~A) {~%~{~A~}}~%"
(conv-form (first args))
(loop-conv-stmts (rest args) returnp)))
((dotimes)
(unless (and (>= (length args) 1) (= (length (first args)) 2))
(error "Invalid # of args for shader dotimes"))
(let ((new-vars (cons (cons (caar args) (conv-shader-var (caar args) t)) vars)))
(format nil "for (int ~A = 0; ~1:*~A < ~A; ~2:*~A++~1*) {~%~{~A~}}~%"
(conv-shader-form (caar args) new-vars funs)
(conv-shader-form (cadar args) new-vars funs)
(loop for x on (cdr args)
collect (conv-shader-stmt (car x) new-vars funs
(and returnp (not (cdr x))))))))
((for)
(unless (and (>= (length args) 1) (= (length (first args)) 3))
(error "Invalid # of args for shader for"))
(format nil "for (~A;~A;~A) {~%~{~A~}}~%"
(conv-form (caar args))
(conv-form (cadar args))
(conv-form (caddar args))
(loop-conv-stmts (cdr args) returnp)))
((let let*)
(unless (>= (length args) 1)
(error "Invalid # of args for shader let"))
(let ((new-vars (nconc (loop for decl in (first args)
if (consp (car decl))
collect (cons (caar decl) (conv-shader-var (caar decl) t))
else
collect (cons (car decl) (conv-shader-var (car decl) t)))
vars)))
(format nil "{~%~{~A ~A~:[~; = ~A~];~%~}~{~A~}}~%"
(loop for decl in (first args)
if (consp (car decl))
nconc (list
(conv-shader-type (cadar decl))
(conv-shader-form (caar decl) new-vars funs)
t (conv-shader-form (cadr decl) new-vars funs))
else
nconc (list
(conv-shader-type (cadr decl))
(conv-shader-form (car decl) new-vars funs)
nil))
(loop for x on (rest args)
collect (conv-shader-stmt (car x) new-vars funs
(and returnp (not (cdr x))))))))
((setf)
(unless (= (mod (length args) 2) 0)
(error "Invalid # of args for shader setf"))
(format nil "~{~A = ~A;~%~}"
(loop for x in args collect (conv-form x))))
(t
(format nil "~:[~;return ~]~A;~%" returnp (conv-form stmt)))))))
(defun conv-shader-fun (name return-type params body vars funs)
(let ((new-vars (nconc (loop for decl in params
collect (cons (car decl) (conv-shader-var (car decl))))
vars)))
(format nil "~A ~A(~{~A ~A~^, ~}) {~%~{~A~}}"
(conv-shader-type return-type) name
(loop for decl in params
nconc (list (conv-shader-type (cadr decl))
(conv-shader-form (car decl) new-vars funs)))
(loop for x on body
collect (conv-shader-stmt (car x) new-vars funs
(not (or (cdr x) (eq return-type :void))))))))
(defun conv-shader-io
(mode name &key type
(location nil)
(component nil)
(binding nil)
(top-left-origin-p nil)
(pixel-coords-p nil)
&allow-other-keys)
(format nil "~:[~;~1:*layout(~{~A~^, ~}) ~]~(~A~) ~A ~A;~%"
(loop for val in (list location component binding top-left-origin-p pixel-coords-p)
for key in (list "location" "component" "binding" "origin_upper_left" "pixel_center_integer")
if (eq val t)
collect key
else if val
collect (format nil "~A=~D" key val))
mode (conv-shader-type type) (conv-shader-var name)))
(defun conv-shader-part (name part version in-vars out-vars uniform-vars funs)
(apply #'concatenate 'string
(format nil "#version ~D core~%// GLSL-ified Lisp shader: ~S~S~%" version name part)
(nconc
(loop for var in in-vars
collect (apply #'conv-shader-io :in var))
(loop for var in out-vars
collect (apply #'conv-shader-io :out var))
(loop for var in uniform-vars
collect (apply #'conv-shader-io :uniform var))
funs)))
(defun transpile-shader (name &key
version
((:in vert-inputs))
((:inter inter-vars))
((:out frag-outputs))
((:uniform uniform-vars))
((:vert vert-body))
((:frag frag-body)))
"Translate Lisp shader code to GLSL."
;; create implicit inter vars
(replace-xref-vars frag-body vert-inputs
(lambda (var-entry)
(let* ((orig-var (car var-entry))
(inter-var-entry (find orig-var inter-vars
:key (lambda (e) (getf (cdr e) :orig-var)))))
(if inter-var-entry
(car inter-var-entry)
(let ((new-var (gensym (symbol-name orig-var))))
(push `(,new-var :orig-var ,orig-var :type ,(getf (cdr var-entry) :type))
inter-vars)
(push `(setf ,new-var ,orig-var) vert-body)
new-var)))))
(let* ((vert-vars (nconc (loop for var-entry in (append inter-vars vert-inputs uniform-vars)
collect (cons (car var-entry) (conv-shader-var (car var-entry))))
*vert-builtins*))
(frag-vars (nconc (loop for var-entry in (append frag-outputs inter-vars uniform-vars)
collect (cons (car var-entry) (conv-shader-var (car var-entry))))
*frag-builtins*))
(vert-uniforms ()) (frag-uniforms ())
vert-glsl frag-glsl)
(replace-xref-vars vert-body uniform-vars
(lambda (var-entry)
(pushnew var-entry vert-uniforms)
(car var-entry)))
(replace-xref-vars frag-body uniform-vars
(lambda (var-entry)
(pushnew var-entry frag-uniforms)
(car var-entry)))
(setf vert-glsl
(conv-shader-part name :vert version
vert-inputs inter-vars vert-uniforms
(list (conv-shader-fun "main" :void () vert-body vert-vars *shader-funs*)))
frag-glsl
(conv-shader-part name :frag version
inter-vars frag-outputs frag-uniforms
(list (conv-shader-fun "main" :void () frag-body frag-vars *shader-funs*))))
`(:vert ,vert-glsl :frag ,frag-glsl
(:in ,vert-inputs :inter ,inter-vars :out ,frag-outputs :uniform ,uniform-vars
:version ,version :vert ,vert-body :frag ,frag-body))))
(defmacro define-shader (name (&key
((:in (&rest vert-inputs)) ())
((:inter (&rest inter-vars)) ())
((:out (&rest frag-outputs)) ())
((:uniform (&rest uniform-vars)) ()))
&key
((:vert (&body vert-body)))
((:frag (&body frag-body)))
version)
"Define a GLSL shader with Lisp code."
`(defparameter ,name (transpile-shader ',name
:version ,version
:in ',vert-inputs
:inter ',inter-vars
:out ',frag-outputs
:uniform ',uniform-vars
:vert ',vert-body :frag ',frag-body)))