Teaching myself GLSL shaders

[EthernautParticipant]

So I finally started learning GLSL. The best resource I’ve found so far is this (still incomplete) amazing interactive book: https://thebookofshaders.com

I’ve been converting the examples in the book to work with Monkey2:
https://github.com/DoctorWhoof/Mojo-Shader-Tests

It started pretty well, but I stopped in example #7 when I tried to make a shader that works in 3D. I get no errors, but nothing displays either… switching the material to a PbrMaterial displays fine, so it’s definitely either the shader or the TestMaterial class. I was hoping for a very simple “unlit” shader just to begin with. What am I missing?

My second question is: where can I find any reference on what the Mojo’s render passes are? I’m ignoring them for now… maybe that’s where the problem is?

Here’s the M2 code:

Monkey

#Import "<std>" #Import "<mojo>" #Import "<mojo3d>" #Import "shaders/test07_3d.glsl" Using std.. Using mojo.. Using mojo3d.. Class MyWindow Extends Window Field img :Image Field testShader :Shader Field scene:Scene Field cube:Model Field camera:Camera Field light:Light Method New() Super.New( "Shader test",1024,600,WindowFlags.Resizable ) scene = Scene.GetCurrent() scene.ClearColor = Color.DarkGrey Local testShader := New Shader( "test06", LoadString("asset::test07_3d.glsl"), "" ) img = New Image( 512, 512, TextureFlags.FilterMipmap, testShader ) img.Handle = New Vec2f( 0.5 ) Local mat := New TestMaterial( testShader ) ' Local mat := New PbrMaterial( Color.Red ) cube = Model.CreateBox( New Boxf(-1,-1,-1,1,1,1), 1, 1, 1, mat ) camera = New Camera camera.Move( 0, 5, -5 ) camera.PointAt( cube ) camera.FOV = 45 light=New Light light.Rotate( 30, 60, 0 ) End Method OnRender( canvas:Canvas ) Override App.RequestRender() cube.Rotate( 0, .5, 0 ) scene.Render( canvas, camera ) End End Function Main() New AppInstance New MyWindow App.Run() End '********************************* Materials ********************************* Class TestMaterial Extends Material Property ColorTexture:Texture() Return Uniforms.GetTexture( "ColorTexture" ) Setter( texture:Texture ) Uniforms.SetTexture( "ColorTexture",texture ) End Property ColorFactor:Color() Return Uniforms.GetColor( "ColorFactor" ) Setter( color:Color ) Uniforms.SetColor( "ColorFactor",color ) End Method New( shader:Shader ) Super.New( shader ) BlendMode=BlendMode.Alpha CullMode=CullMode.None ColorTexture=Texture.ColorTexture( Color.White ) ColorFactor = Color.White End Method New( material:TestMaterial ) Super.New( material ) End Method Copy:TestMaterial() Override Return New TestMaterial( Self ) End End

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#Import "<std>" #Import "<mojo>" #Import "<mojo3d>" #Import "shaders/test07_3d.glsl"   Using std.. Using mojo.. Using mojo3d..   Class MyWindow Extends Window   Field img :Image Field testShader :Shader   Field scene:Scene Field cube:Model Field camera:Camera Field light:Light   Method New() Super.New( "Shader test",1024,600,WindowFlags.Resizable  ) scene = Scene.GetCurrent() scene.ClearColor = Color.DarkGrey   Local testShader := New Shader( "test06", LoadString("asset::test07_3d.glsl"), "" )   img = New Image( 512, 512, TextureFlags.FilterMipmap, testShader ) img.Handle = New Vec2f( 0.5 )   Local mat := New TestMaterial( testShader ) ' Local mat := New PbrMaterial( Color.Red )   cube = Model.CreateBox( New Boxf(-1,-1,-1,1,1,1), 1, 1, 1, mat  ) camera = New Camera camera.Move( 0, 5, -5 ) camera.PointAt( cube ) camera.FOV = 45 light=New Light light.Rotate( 30, 60, 0 ) End   Method OnRender( canvas:Canvas ) Override App.RequestRender() cube.Rotate( 0, .5, 0 ) scene.Render( canvas, camera ) End End     Function Main() New AppInstance New MyWindow App.Run() End     '********************************* Materials *********************************     Class TestMaterial Extends Material Property ColorTexture:Texture() Return Uniforms.GetTexture( "ColorTexture" ) Setter( texture:Texture ) Uniforms.SetTexture( "ColorTexture",texture ) End Property ColorFactor:Color() Return Uniforms.GetColor( "ColorFactor" ) Setter( color:Color ) Uniforms.SetColor( "ColorFactor",color ) End Method New( shader:Shader ) Super.New( shader ) BlendMode=BlendMode.Alpha CullMode=CullMode.None ColorTexture=Texture.ColorTexture( Color.White ) ColorFactor = Color.White End Method New( material:TestMaterial ) Super.New( material ) End   Method Copy:TestMaterial() Override Return New TestMaterial( Self ) End End

And here’s the shader. I made the color a simple red just to test it.

C

//@renderpasses 0 varying vec4 v_Color; varying vec2 v_TexCoord0; //@vertex attribute vec4 a_Position; attribute vec2 a_TexCoord0; attribute vec4 a_Color; uniform mat4 r_ModelViewProjectionMatrix; void main(){ v_TexCoord0 = a_TexCoord0; v_Color = a_Color; gl_Position=r_ModelViewProjectionMatrix * a_Position; } //@fragment uniform sampler2D m_ColorTexture; uniform vec4 m_ColorFactor; uniform float m_Time; void main(){ // vec3 color=pow( texture2D( m_ColorTexture,v_TexCoord0 ).rgb,vec3( 2.2 ) ) * m_ColorFactor.rgb; vec3 color = vec3( 1.0, 0.0, 0.0 ) * v_Color; float alpha=texture2D( m_ColorTexture, v_TexCoord0 ).a * m_ColorFactor.a; gl_FragColor=vec4( color * alpha, alpha ); }

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//@renderpasses 0 varying vec4 v_Color; varying vec2 v_TexCoord0;   //@vertex attribute vec4 a_Position; attribute vec2 a_TexCoord0; attribute vec4 a_Color;   uniform mat4 r_ModelViewProjectionMatrix;   void main(){ v_TexCoord0 = a_TexCoord0; v_Color = a_Color; gl_Position=r_ModelViewProjectionMatrix * a_Position; }   //@fragment uniform sampler2D m_ColorTexture; uniform vec4 m_ColorFactor; uniform float m_Time;   void main(){ // vec3 color=pow( texture2D( m_ColorTexture,v_TexCoord0 ).rgb,vec3( 2.2 ) ) * m_ColorFactor.rgb; vec3 color = vec3( 1.0, 0.0, 0.0 ) * v_Color; float alpha=texture2D( m_ColorTexture, v_TexCoord0 ).a * m_ColorFactor.a;   gl_FragColor=vec4( color * alpha, alpha ); }

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