Basic example of OpenGL binding

Diya/DiyaBoot.class.st

@@ -5,12 +5,15 @@ Class {
 		'running',
 		'window',
 		'renderer',
+		'context',
 		'display'
 	],
 	#classVars : [
 		'singleton'
 	],
 	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes',
 		'SDL2Constants',
 		'SDL2Types'
 	],
@@ -38,6 +41,14 @@ DiyaBoot class >> uniqueInstance [
 	^ singleton
 ]
 
+{ #category : #events }
+DiyaBoot >> createGLContext [
+	context :=  SDL2 glCreateContext:  window.
+	context ifNil: [ ^self error: SDL2 getErrorMessage ].
+	^context 
+	
+]
+
 { #category : #events }
 DiyaBoot >> createRenderer [
 	renderer := window primCreateRenderer: -1 flags: SDL_RENDERER_ACCELERATED.
@@ -48,16 +59,15 @@ DiyaBoot >> createRenderer [
 
 { #category : #events }
 DiyaBoot >> createWindow [
-	|handle|
+	window := SDL2 createWindow: 'Diya'
-	handle := SDL2 createWindow: 'Diya'
 			x: 0
 			y: 0
 			width: display w
 			height: display h
-			flags: SDL_WINDOW_SHOWN.
+			flags: SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL.
-	handle ifNil: [ ^self error: SDL2 getErrorMessage ].
+	window ifNil: [ ^self error: SDL2 getErrorMessage ].
 	"handle fullscreen: SDL_WINDOW_FULLSCREEN."
-	^handle
+	^window
 ]
 
 { #category : #events }
@@ -75,7 +85,7 @@ DiyaBoot >> initialize [
 	running := true.
 	display := nil.
 	window := nil.
-	renderer := nil.
+	context := nil.
 ]
 
 { #category : #events }
@@ -105,12 +115,8 @@ DiyaBoot >> render [
 		[ (SDL2 pollEvent: event) > 0 ] whileTrue: [
 			self processEvent: event
 		].
-		renderer drawColorR: self randomColorChannel
+		self step.
-				g: self randomColorChannel
+		SDL2 glSwapWindow: window.
-				b: self randomColorChannel
-				a: 255.
-		renderer clear.
-		renderer present.
 		SDL2 delay: 50. 
 	].
 ]
@@ -134,6 +140,8 @@ DiyaBoot >> run: screenSize app: application [
 	it is always the #run command that is executed
 	automatically.
 	"
+	OpenGLTypes initialize.
+	OpenGLConstants initialize.
 	self init.
 	display w: screenSize x.
 	display h: screenSize y.
@@ -172,8 +180,10 @@ DiyaBoot >> showSystemInfo [
 		 stream nextPutAll:  rinfo name readString; nextPutAll:' '.
 	].
 	stream cr.
-	renderer primGetRendererInfo: rinfo.
+	renderer ifNotNil:[
-	stream nextPutAll: 'SDL_RENDER_DRIVER selected: '; nextPutAll: rinfo name readString; cr.
+		renderer primGetRendererInfo: rinfo.
+		stream nextPutAll: 'SDL_RENDER_DRIVER selected: '; nextPutAll: rinfo name readString; cr.
+	].
 	stream nextPutAll:'Display resolution: ';
 		nextPutAll:display w asString;
 		nextPutAll: 'x';
@@ -185,11 +195,23 @@ DiyaBoot >> showSystemInfo [
 { #category : #events }
 DiyaBoot >> startx [
 	display ifNil: [ ^self error: 'Please run #init before this method' ].
-	window := self createWindow.
+	self createWindow.
-	renderer := self createRenderer.
+	self createGLContext.
+	"self createRenderer."
 	self showSystemInfo.
 	self render.
-	renderer destroy.
+	context delete.
 	window destroy.
 	SDL2 quit.
 ]
+
+{ #category : #events }
+DiyaBoot >> step [
+	OpenGL begin: GL_TRIANGLES.
+	"draw a simple triangle here"
+	OpenGL color3fR: 0.1 G:0.2  B: 0.3.
+	OpenGL vertex3fX: 0 Y: 0  Z: 0.
+	OpenGL vertex3fX: 1 Y: 0  Z: 0.
+	OpenGL vertex3fX: 0 Y: 1  Z: 0.  
+	OpenGL end.
+]

Diya/DiyaFFIBase.class.st

@@ -9,6 +9,11 @@ DiyaFFIBase class >> checkSymbol [
 	^self subclassResponsibility 
 ]
 
+{ #category : #accessing }
+DiyaFFIBase class >> ffiLibraryName [
+	^ self moduleName 
+]
+
 { #category : #accessing }
 DiyaFFIBase class >> libNames [
 	^self subclassResponsibility
@@ -23,3 +28,8 @@ DiyaFFIBase class >> moduleName [
 	].
 	self error: 'Unable to find FFI library (', self checkSymbol, ')'.
 ]
+
+{ #category : #'library path' }
+DiyaFFIBase >> ffiLibraryName [ 
+	^self class ffiLibraryName
+]

Diya/OpenGL.class.st

@@ -0,0 +1,54 @@
+Class {
+	#name : #OpenGL,
+	#superclass : #DiyaFFIBase,
+	#pools : [
+		'OpenGLConstants',
+		'OpenGLTypes'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #accessing }
+OpenGL class >> begin: mode [
+	^ self ffiCall: #(void glBegin(GLenum mode))
+]
+
+{ #category : #accessing }
+OpenGL class >> checkSymbol [
+	^#glBegin
+]
+
+{ #category : #'as yet unclassified' }
+OpenGL class >> clear: mask [
+	^ self ffiCall: #(void glClear(GLbitfield mask))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGL class >> clearColorR: red G: green B: blue A:alpha [
+	^self ffiCall: #(void glClearColor(	GLclampf red,GLclampf green,GLclampf blue,GLclampf alpha))
+]
+
+{ #category : #accessing }
+OpenGL class >> color3fR: red G: green B: blue [
+	^self ffiCall: #(void glColor3f(GLfloat red,GLfloat green,GLfloat blue))
+]
+
+{ #category : #accessing }
+OpenGL class >> end [
+	^ self ffiCall: #(void glEnd( void ))
+]
+
+{ #category : #accessing }
+OpenGL class >> libNames [
+	^#('libGL.so.1')
+]
+
+{ #category : #accessing }
+OpenGL class >> vertex3fX:x Y:y Z:z [
+	^self ffiCall: #(void glVertex3f(	GLfloat x,GLfloat y,GLfloat z))
+]
+
+{ #category : #'as yet unclassified' }
+OpenGL class >> viewportX: x Y:y W: width H:height [
+	^ self ffiCall: #(void glViewport(GLint x,GLint y,GLsizei width,GLsizei height))
+]

Diya/OpenGLConstants.class.st

@@ -0,0 +1,49 @@
+Class {
+	#name : #OpenGLConstants,
+	#superclass : #SharedPool,
+	#classVars : [
+		'GL_ACCUM_BUFFER_BIT',
+		'GL_COLOR_BUFFER_BIT',
+		'GL_DEPTH_BUFFER_BIT',
+		'GL_LINES',
+		'GL_LINE_LOOP',
+		'GL_LINE_STRIP',
+		'GL_POINTS',
+		'GL_POLYGON',
+		'GL_QUADS',
+		'GL_QUAD_STRIP',
+		'GL_STENCIL_BUFFER_BIT',
+		'GL_TRIANGLES',
+		'GL_TRIANGLE_FAN',
+		'GL_TRIANGLE_STRIP'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #'class initialization' }
+OpenGLConstants class >> initCommonMask [
+	GL_COLOR_BUFFER_BIT := 16r00004000.
+	GL_DEPTH_BUFFER_BIT := 16r00000100.
+	GL_ACCUM_BUFFER_BIT := 16r00000200.
+	GL_STENCIL_BUFFER_BIT := 16r00000400.
+]
+
+{ #category : #'class initialization' }
+OpenGLConstants class >> initCommonMode [
+	GL_TRIANGLES := 16r0004.
+	GL_POINTS := 16r0000.
+	GL_LINES := 16r0001.
+	GL_LINE_STRIP := 16r0003.
+	GL_LINE_LOOP := 16r0002.
+	GL_TRIANGLE_STRIP := 16r0005.
+	GL_TRIANGLE_FAN := 16r0006.
+	GL_QUADS := 16r0007.
+	GL_QUAD_STRIP := 16r0008.
+	GL_POLYGON := 16r0009.
+]
+
+{ #category : #'class initialization' }
+OpenGLConstants class >> initialize [
+	self initCommonMode.
+	self initCommonMask.
+]

Diya/OpenGLTypes.class.st

@@ -0,0 +1,53 @@
+Class {
+	#name : #OpenGLTypes,
+	#superclass : #SharedPool,
+	#classVars : [
+		'GLbitfield',
+		'GLboolean',
+		'GLbyte',
+		'GLclampd',
+		'GLclampf',
+		'GLdouble',
+		'GLenum',
+		'GLfixed',
+		'GLfloat',
+		'GLhalf',
+		'GLint',
+		'GLint64',
+		'GLintptr',
+		'GLshort',
+		'GLsizei',
+		'GLsizeiptr',
+		'GLsync',
+		'GLubyte',
+		'GLuint',
+		'GLuint64',
+		'GLushort'
+	],
+	#category : #'Diya-OpenGL'
+}
+
+{ #category : #'class initialization' }
+OpenGLTypes class >> initialize [ 
+	GLfloat := #float.
+	GLubyte := #uint8.
+	GLenum := #int32.
+	GLboolean := #uint8.
+	GLbitfield := #int32.
+	GLbyte := #int8.
+	GLclampd := #double.
+	GLclampf := #float.
+	GLdouble := #double.
+	GLfixed := #int32.
+	GLhalf := #uint16.
+	GLint := #int32.
+	GLint64 := #int64.
+	GLintptr := Smalltalk wordSize = 8 ifTrue: [ #int64 ] ifFalse: [ #int32 ].
+	GLshort := #int16.
+	GLsizei := #int32.
+	GLsizeiptr := Smalltalk wordSize = 8 ifTrue: [ #int64 ] ifFalse: [ #int32 ].
+	GLsync := Smalltalk wordSize = 8 ifTrue: [ #int64 ] ifFalse: [ #int32 ].
+	GLuint := #uint32.
+	GLuint64 := #uint64.
+	GLushort := #uint16.
+]