diff --git a/Diya/DiyaBoot.class.st b/Diya/DiyaBoot.class.st
index 359f2be..2973141 100644
--- a/Diya/DiyaBoot.class.st
+++ b/Diya/DiyaBoot.class.st
@@ -1,15 +1,13 @@
 Class {
 	#name : #DiyaBoot,
-	#superclass : #DiyaBaseObject,
+	#superclass : #DiyaSingleton,
 	#instVars : [
 		'running',
 		'window',
 		'renderer',
 		'context',
-		'display'
-	],
-	#classVars : [
-		'singleton'
+		'display',
+		'clock'
 	],
 	#pools : [
 		'OpenGLConstants',
@@ -20,16 +18,6 @@ Class {
 	#category : #'Diya-Runtime'
 }
 
-{ #category : #'instance creation' }
-DiyaBoot class >> new [
-	self error: 'Use #uniqueInstance'
-]
-
-{ #category : #'instance creation' }
-DiyaBoot class >> reset [
-	singleton := nil
-]
-
 { #category : #'instance creation' }
 DiyaBoot class >> startUp: status [
 	self startx.
@@ -40,12 +28,6 @@ DiyaBoot class >> startx [
 	self uniqueInstance run
 ]
 
-{ #category : #'instance creation' }
-DiyaBoot class >> uniqueInstance [ 
-	singleton ifNil: [ singleton := super new ].
-	^ singleton
-]
-
 { #category : #events }
 DiyaBoot >> createGLContext [
 	context :=  SDL2 glCreateContext:  window.
@@ -91,6 +73,7 @@ DiyaBoot >> initialize [
 	display := nil.
 	window := nil.
 	context := nil.
+	clock := DiyaClock uniqueInstance.
 ]
 
 { #category : #events }
@@ -101,6 +84,7 @@ DiyaBoot >> processEvent: event [
 	mappedEvt type = SDL_QUIT ifTrue:[ ^running:= false ].
 	mappedEvt type = SDL_FINGERDOWN ifTrue:[^self setCursorPosition: mappedEvt ].
 	mappedEvt type = SDL_FINGERMOTION ifTrue:[^self setCursorPosition: mappedEvt ].
+	mappedEvt type = SDL_MOUSEMOTION ifTrue:[DiyaRendererContext uniqueInstance mouse: mappedEvt].
 ]
 
 { #category : #events }
@@ -167,6 +151,8 @@ DiyaBoot >> run: screenSize app: application [
 	display h: screenSize y.
 	self startx.
 	self class reset.
+	DiyaClock reset.
+	DiyaRendererContext reset.
 	Smalltalk garbageCollect.
 ]
 
@@ -220,6 +206,7 @@ DiyaBoot >> startx [
 	self createGLContext.
 	self createRenderer.
 	self showSystemInfo.
+	DiyaRendererContext uniqueInstance display: display.
 	sr := SimpleDiyaRenderer new.
 	sr setup.
 	self render:sr.
diff --git a/Diya/DiyaClock.class.st b/Diya/DiyaClock.class.st
new file mode 100644
index 0000000..86a2f03
--- /dev/null
+++ b/Diya/DiyaClock.class.st
@@ -0,0 +1,18 @@
+Class {
+	#name : #DiyaClock,
+	#superclass : #DiyaSingleton,
+	#instVars : [
+		'monotonic'
+	],
+	#category : #'Diya-Runtime'
+}
+
+{ #category : #initialization }
+DiyaClock >> elapsedTime [
+ ^(DateAndTime now) - monotonic 
+]
+
+{ #category : #initialization }
+DiyaClock >> initialize [
+	monotonic := DateAndTime now.
+]
diff --git a/Diya/DiyaRenderer.class.st b/Diya/DiyaRenderer.class.st
index 1a25251..bd5b8fe 100644
--- a/Diya/DiyaRenderer.class.st
+++ b/Diya/DiyaRenderer.class.st
@@ -1,6 +1,9 @@
 Class {
 	#name : #DiyaRenderer,
 	#superclass : #DiyaBaseObject,
+	#instVars : [
+		'context'
+	],
 	#pools : [
 		'OpenGLConstants',
 		'OpenGLTypes'
@@ -8,11 +11,22 @@ Class {
 	#category : #'Diya-Graphics'
 }
 
+{ #category : #'instance creation' }
+DiyaRenderer class >> fromContext: ctx [
+	^self new context: ctx; yourself
+]
+
 { #category : #deleting }
 DiyaRenderer >> destroy [ 
 	^ self subclassResponsibility 
 ]
 
+{ #category : #initialization }
+DiyaRenderer >> initialize [
+	super initialize.
+	context := DiyaRendererContext uniqueInstance
+]
+
 { #category : #deleting }
 DiyaRenderer >> render [ 
 	^ self subclassResponsibility 
diff --git a/Diya/DiyaRendererContext.class.st b/Diya/DiyaRendererContext.class.st
new file mode 100644
index 0000000..5b0ac21
--- /dev/null
+++ b/Diya/DiyaRendererContext.class.st
@@ -0,0 +1,38 @@
+Class {
+	#name : #DiyaRendererContext,
+	#superclass : #DiyaSingleton,
+	#instVars : [
+		'mouse',
+		'display'
+	],
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-Graphics'
+}
+
+{ #category : #accessing }
+DiyaRendererContext >> display [
+	^ display
+]
+
+{ #category : #accessing }
+DiyaRendererContext >> display: anObject [
+	display := anObject
+]
+
+{ #category : #accessing }
+DiyaRendererContext >> mouse [
+	^ mouse
+]
+
+{ #category : #accessing }
+DiyaRendererContext >> mouse: anObject [
+	mouse := anObject
+]
+
+{ #category : #'as yet unclassified' }
+DiyaRendererContext >> resolution [
+	^ (display w) @ (display h)
+]
diff --git a/Diya/DiyaSingleton.class.st b/Diya/DiyaSingleton.class.st
new file mode 100644
index 0000000..7d87291
--- /dev/null
+++ b/Diya/DiyaSingleton.class.st
@@ -0,0 +1,37 @@
+Class {
+	#name : #DiyaSingleton,
+	#superclass : #DiyaBaseObject,
+	#classVars : [
+		'singletons'
+	],
+	#category : #'Diya-Core'
+}
+
+{ #category : #'instance creation' }
+DiyaSingleton class >> cleanUpInstance: singleton [
+	"do nothing for now"
+]
+
+{ #category : #'class initialization' }
+DiyaSingleton class >> initialize [
+	singletons := Dictionary new.
+]
+
+{ #category : #'instance creation' }
+DiyaSingleton class >> new [
+	self error: 'Use #uniqueInstance'
+]
+
+{ #category : #'instance creation' }
+DiyaSingleton class >> reset [
+	|singleton|
+	singleton := singletons at: self class ifAbsent: [ ^ self ].
+	self cleanUpInstance: singleton.
+	singletons removeKey: self class
+]
+
+{ #category : #'instance creation' }
+DiyaSingleton class >> uniqueInstance [ 
+	singletons at: self class ifAbsentPut: super new.
+	^ singletons at: self class
+]
diff --git a/Diya/Duration.extension.st b/Diya/Duration.extension.st
new file mode 100644
index 0000000..3ed0e6b
--- /dev/null
+++ b/Diya/Duration.extension.st
@@ -0,0 +1,6 @@
+Extension { #name : #Duration }
+
+{ #category : #'*Diya' }
+Duration >> asFloat [
+	^ seconds asFloat + (nanos / 1e9) asFloat 
+]
diff --git a/Diya/GLSimpleShader.class.st b/Diya/GLSimpleShader.class.st
index cbf56aa..3d4e2e0 100644
--- a/Diya/GLSimpleShader.class.st
+++ b/Diya/GLSimpleShader.class.st
@@ -7,9 +7,16 @@ Class {
 { #category : #accessing }
 GLSimpleShader class >> fragmentShader [
 	^ '
+#ifdef GL_ES
+precision mediump float;
+#endif
+uniform vec2 u_resolution;
+uniform vec2 u_mouse;
+uniform float u_time;
 void main()
 {
-	gl_FragColor = vec4(0.4,0.4,0.8,1.0);
+    vec2 mouse = vec2(u_mouse)/vec2(u_resolution);
+    gl_FragColor = vec4(mouse.x, mouse.y, abs(sin(u_time)), 1.0);
 }
 '
 ]
diff --git a/Diya/OpenGLSL.class.st b/Diya/OpenGLSL.class.st
index 5636d64..ee47fe6 100644
--- a/Diya/OpenGLSL.class.st
+++ b/Diya/OpenGLSL.class.st
@@ -1,11 +1,9 @@
 Class {
 	#name : #OpenGLSL,
-	#superclass : #DiyaBaseObject,
+	#superclass : #DiyaSingleton,
 	#instVars : [
-		'programID'
-	],
-	#classVars : [
-		'singleton'
+		'programID',
+		'uniforms'
 	],
 	#pools : [
 		'OpenGLConstants',
@@ -19,6 +17,11 @@ OpenGLSL class >> attachShader: shader to: program [
 	^self ffiCall: #(void glAttachShader(GLuint program,GLuint shader))
 ]
 
+{ #category : #'instance creation' }
+OpenGLSL class >> cleanUpInstance: singleton [
+	singleton delete
+]
+
 { #category : #'as yet unclassified' }
 OpenGLSL class >> compileShader: shader [
 	^ self ffiCall: #(void glCompileShader(	GLuint shader))
@@ -74,33 +77,24 @@ OpenGLSL class >> getShaderiv:shader parameterName: pname params: ptr [
 	^ self ffiCall: #(void glGetShaderiv(GLuint shader,GLenum pname,GLint *ptr))
 ]
 
+{ #category : #'as yet unclassified' }
+OpenGLSL class >> getUniformLocation: uname ofProgram: program [
+	^self ffiCall:#(GLint glGetUniformLocation(	GLuint program,const GLchar *uname))
+]
+
 { #category : #'as yet unclassified' }
 OpenGLSL class >> linkProgram:program [
 	^self ffiCall: #(void glLinkProgram(GLuint program))
 ]
 
-{ #category : #'instance creation' }
-OpenGLSL class >> new [
-	self error: 'Use #uniqueInstance'
-]
-
-{ #category : #'instance creation' }
-OpenGLSL class >> reset [
-	singleton ifNotNil: [ 
-		singleton delete.
-	].
-	singleton := nil
-]
-
 { #category : #'as yet unclassified' }
 OpenGLSL class >> setShaderSourceFor: shader count: n string: s length: l [
 	^ self ffiCall: #(void glShaderSource(	GLuint shader,GLsizei n,const void* s,const GLint *l))
 ]
 
-{ #category : #'instance creation' }
-OpenGLSL class >> uniqueInstance [
-	singleton ifNil: [ singleton := super new. singleton compile ].
-	^ singleton
+{ #category : #'as yet unclassified' }
+OpenGLSL class >> systemUniforms [
+	^#(u_time u_resolution u_mouse)
 ]
 
 { #category : #'as yet unclassified' }
@@ -113,6 +107,11 @@ OpenGLSL class >> vertextShader [
 	^ self subclassResponsibility
 ]
 
+{ #category : #initialization }
+OpenGLSL >> addUniform: uname of: utype [
+	uniforms at:uname put: (utype fromName: uname).
+]
+
 { #category : #compiling }
 OpenGLSL >> checkStatus:status of: id [
 	|infoLength buffer result|
@@ -151,7 +150,8 @@ OpenGLSL >> compile [
 	OpenGLSL detachShaderFrom: programID  shader: vertexShaderID.
 	OpenGLSL detachShaderFrom: programID  shader: fragmentShaderID.
 	OpenGLSL deleteShader: vertexShaderID.
-	OpenGLSL deleteShader: fragmentShaderID 
+	OpenGLSL deleteShader: fragmentShaderID.
+	self locateUniforms
 ]
 
 { #category : #compiling }
@@ -184,6 +184,44 @@ OpenGLSL >> getSourcePtr: string for: shaderId [
 	OpenGLSL setShaderSourceFor: shaderId count: 1 string: xarray getHandle length: nil.
 ]
 
+{ #category : #'submorphs-add/remove' }
+OpenGLSL >> getUniformLocation:uname [
+	^ self class getUniformLocation: uname asString ofProgram: programID
+]
+
+{ #category : #initialization }
+OpenGLSL >> initialize [
+	super initialize.
+	uniforms := Dictionary new.
+	self addUniform: #u_time of: Uniform1F.
+	self addUniform: #u_resolution of: Uniform2F.
+	self addUniform: #u_mouse of: Uniform2F.
+	self setUpUniforms.
+	self compile
+]
+
+{ #category : #compiling }
+OpenGLSL >> locateUniforms [
+	|loc|
+	uniforms valuesDo: [ :uniform|
+		loc := self getUniformLocation: uniform uname.
+		loc = -1 ifFalse:[uniform location: loc]
+	]
+]
+
+{ #category : #initialization }
+OpenGLSL >> setUniform: uname value: values [
+	|uniform|
+	uniform := uniforms at: uname asSymbol ifAbsent:[
+		^self error: 'Uniform', uname, 'is not defined in this program'].
+	uniform value: values
+]
+
+{ #category : #initialization }
+OpenGLSL >> setUpUniforms [
+	"do nothing, custom uniform can be set up by subclass"
+]
+
 { #category : #'submorphs-add/remove' }
 OpenGLSL >> use [
 	^OpenGLSL useProgram: programID 
diff --git a/Diya/OpenGLSLUniform.class.st b/Diya/OpenGLSLUniform.class.st
new file mode 100644
index 0000000..148267b
--- /dev/null
+++ b/Diya/OpenGLSLUniform.class.st
@@ -0,0 +1,108 @@
+Class {
+	#name : #OpenGLSLUniform,
+	#superclass : #DiyaBaseObject,
+	#instVars : [
+		'uname',
+		'location',
+		'value'
+	],
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> ffiLibraryName [ 
+	^ OpenGL ffiLibraryName 
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> fromName: uname [
+	^self new uname: uname; yourself
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> fromName: uname at: location [
+	^self new uname: uname; location: location; yourself
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform1f: location value: v0 [
+	^self ffiCall: #(void glUniform1f(GLint location,GLfloat v0))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform1i: location value: v0 [ 
+	^self ffiCall: #(void glUniform1i(GLint location,GLint v0))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform2f: location value: v0 value: v1 [
+	^self ffiCall: #(void glUniform2f(GLint location,GLfloat v0,GLfloat v1))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform2i: location value: v0 value: v1 [
+	^self ffiCall: #(void glUniform2i(GLint location,GLint v0,GLint v1))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform3f: location value: v0 value: v1 value: v2 [
+	^self ffiCall: #(void glUniform3f(GLint location,GLfloat v0,GLfloat v1,GLfloat v2))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform3i: location value: v0 value: v1 value: v2 [
+	^self ffiCall: #(void glUniform3i(GLint location,GLint v0,GLint v1,GLint v2))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform4f: location value: v0 value: v1 value: v2 value: v3 [
+	^self ffiCall: #(void glUniform4f(GLint location,GLfloat v0,GLfloat v1,GLfloat v2, GLfloat v3))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGLSLUniform class >> uniform4i: location value: v0 value: v1 value: v2 value: v3 [
+	^self ffiCall: #(void glUniform4i(GLint location,GLint v0,GLint v1,GLint v2, GLint v3))
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> location [
+	^ location
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> location: anObject [
+	location := anObject
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> setUniformValue [
+	 ^ self subclassResponsibility
+ 	
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> uname [
+	^ uname
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> uname: anObject [
+	uname := anObject
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> value [
+ ^ value
+]
+
+{ #category : #accessing }
+OpenGLSLUniform >> value: values [
+	location = -1 ifTrue: [ ^self ].
+	value := values.
+	self setUniformValue.
+ 	
+]
diff --git a/Diya/SimpleDiyaRenderer.class.st b/Diya/SimpleDiyaRenderer.class.st
index 552817d..89bf219 100644
--- a/Diya/SimpleDiyaRenderer.class.st
+++ b/Diya/SimpleDiyaRenderer.class.st
@@ -14,12 +14,12 @@ Class {
 SimpleDiyaRenderer >> destroy [ 
 	vertexBuffer delete.
 	arrayBuffer delete.
-	shader delete.
 	GLSimpleShader reset.
 ]
 
 { #category : #initialization }
-SimpleDiyaRenderer >> initialize [ 
+SimpleDiyaRenderer >> initialize [
+	super initialize.
 	vertexBuffer := OpenGLVertexBuffer new.
 	arrayBuffer := OpenGLVertexArray new.
 	bufferData := FFIExternalArray externalNewType: GLfloat size: 9.
@@ -33,6 +33,12 @@ SimpleDiyaRenderer >> render [
 	OpenGL clearColorR: 1.0 G: 0  B: 1.0  A:0.
 	OpenGL clear: GL_COLOR_BUFFER_BIT.
 	shader use.
+	shader setUniform: #u_time value: DiyaClock uniqueInstance elapsedTime asFloat.
+	shader setUniform: #u_resolution value: { context resolution x. context resolution y }.
+	context mouse ifNotNil: [
+		shader setUniform: #u_mouse value: { context mouse x. context mouse y }.
+	].
+ 
 	arrayBuffer enableAttribute: 0.
 	vertexBuffer bind: GL_ARRAY_BUFFER.
 	OpenGLVertexArray  vertexAttributePointerIndex: 0 size:3  type: GL_FLOAT normalized: GL_FALSE stride: 0 pointer: nil .
diff --git a/Diya/Uniform1F.class.st b/Diya/Uniform1F.class.st
new file mode 100644
index 0000000..263cf04
--- /dev/null
+++ b/Diya/Uniform1F.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform1F,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform1F >> setUniformValue [
+	OpenGLSLUniform uniform1f: location value: value
+]
diff --git a/Diya/Uniform1i.class.st b/Diya/Uniform1i.class.st
new file mode 100644
index 0000000..adf6395
--- /dev/null
+++ b/Diya/Uniform1i.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform1i,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform1i >> setUniformValue [
+	OpenGLSLUniform uniform1i: location value: value
+]
diff --git a/Diya/Uniform2F.class.st b/Diya/Uniform2F.class.st
new file mode 100644
index 0000000..c196654
--- /dev/null
+++ b/Diya/Uniform2F.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform2F,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform2F >> setUniformValue [
+	OpenGLSLUniform uniform2f: location value: value first value: value last
+]
diff --git a/Diya/Uniform2i.class.st b/Diya/Uniform2i.class.st
new file mode 100644
index 0000000..58266ab
--- /dev/null
+++ b/Diya/Uniform2i.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform2i,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform2i >> setUniformValue [
+	OpenGLSLUniform uniform2i: location value: value first value: value last
+]
diff --git a/Diya/Uniform3F.class.st b/Diya/Uniform3F.class.st
new file mode 100644
index 0000000..69aa0e5
--- /dev/null
+++ b/Diya/Uniform3F.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform3F,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform3F >> setUniformValue [
+	OpenGLSLUniform uniform3f: location value: value first value: (value at:2) value: value last
+]
diff --git a/Diya/Uniform3i.class.st b/Diya/Uniform3i.class.st
new file mode 100644
index 0000000..68b912a
--- /dev/null
+++ b/Diya/Uniform3i.class.st
@@ -0,0 +1,14 @@
+Class {
+	#name : #Uniform3i,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform3i >> setUniformValue [
+	OpenGLSLUniform uniform3i: location value: value first value: (value at:2) value: value last
+]
diff --git a/Diya/Uniform4F.class.st b/Diya/Uniform4F.class.st
new file mode 100644
index 0000000..9dd3236
--- /dev/null
+++ b/Diya/Uniform4F.class.st
@@ -0,0 +1,18 @@
+Class {
+	#name : #Uniform4F,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform4F >> setUniformValue [
+	OpenGLSLUniform uniform4f: location
+		value: value first
+		value: (value at:2)
+		value: (value at:3)
+		value: value last
+]
diff --git a/Diya/Uniform4i.class.st b/Diya/Uniform4i.class.st
new file mode 100644
index 0000000..60661eb
--- /dev/null
+++ b/Diya/Uniform4i.class.st
@@ -0,0 +1,18 @@
+Class {
+	#name : #Uniform4i,
+	#superclass : #OpenGLSLUniform,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+Uniform4i >> setUniformValue [
+	OpenGLSLUniform uniform4i: location
+		value: value first
+		value: (value at:2)
+		value: (value at:3)
+		value: value last
+]