Monkey2 OpenGL Experiments

[coconParticipant]

Here is the basic OpenGL rendering test for Monkey2:

Monkey

#Import "<mojo>" Using std.. Using mojo.. Using gles20.. Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End Function LoadSimpleShader:GLuint() Local vertex:String = " attribute vec3 Position; attribute vec3 Color; varying vec3 OutColor; void main() { gl_Position = vec4(Position, 1); OutColor = Color; } " Local fragment:String = " varying vec3 OutColor; void main() { gl_FragColor = vec4(OutColor, 0); } " Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") glBindAttribLocation(program, 1, "Color") Return program End Class MyWindow Extends GLWindow Field vbo:GLuint Field shader:GLuint Field canvas:Canvas Method New() ' Setup OpenGL glViewport(0, 0, Width, Height) glClearColor(0.1, 0.1, 0.5, 1.0) ' declare the shape vertices Local vertices:Float[] = New Float[]( -1,-1,0, 1,0,0, 1,-1,0, 0,1,0, 0, 1,0, 0,0,1) ' Load Shader shader = LoadSimpleShader() Print("Program ID: " + shader) Print("Attribute Location: " + glGetAttribLocation(shader, "Position")) ' Create vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_DYNAMIC_DRAW) End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL Test", 10, 10) End Method OnRenderGL() Override glClear(GL_COLOR_BUFFER_BIT) glUseProgram(shader) glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glEnableVertexAttribArray(1) glVertexAttribPointer(0, 3, GL_FLOAT, False, 24, Cast<Void Ptr>(0)) glVertexAttribPointer(1, 3, GL_FLOAT, False, 24, Cast<Void Ptr>(12)) glDrawArrays(GL_TRIANGLES, 0, 3) End End Function Main() New AppInstance New MyWindow App.Run() End

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#Import "<mojo>"   Using std.. Using mojo.. Using gles20..   Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End   Function LoadSimpleShader:GLuint() Local vertex:String = " attribute vec3 Position; attribute vec3 Color; varying vec3 OutColor; void main() { gl_Position = vec4(Position, 1); OutColor = Color; } "   Local fragment:String = " varying vec3 OutColor; void main() { gl_FragColor = vec4(OutColor, 0); } "   Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") glBindAttribLocation(program, 1, "Color") Return program End   Class MyWindow Extends GLWindow Field vbo:GLuint Field shader:GLuint Field canvas:Canvas Method New() ' Setup OpenGL glViewport(0, 0, Width, Height) glClearColor(0.1, 0.1, 0.5, 1.0) ' declare the shape vertices Local vertices:Float[] = New Float[]( -1,-1,0, 1,0,0, 1,-1,0, 0,1,0, 0, 1,0, 0,0,1) ' Load Shader shader = LoadSimpleShader() Print("Program ID: " + shader) Print("Attribute Location: " + glGetAttribLocation(shader, "Position"))   ' Create vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_DYNAMIC_DRAW)   End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL Test", 10, 10) End Method OnRenderGL() Override glClear(GL_COLOR_BUFFER_BIT) glUseProgram(shader) glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glEnableVertexAttribArray(1) glVertexAttribPointer(0, 3, GL_FLOAT, False, 24, Cast<Void Ptr>(0)) glVertexAttribPointer(1, 3, GL_FLOAT, False, 24, Cast<Void Ptr>(12))   glDrawArrays(GL_TRIANGLES, 0, 3) End End   Function Main() New AppInstance New MyWindow App.Run() End

Later on I will try to figure out the Matrix4 class and make it 3D. If you have any other ideas say it here.

[Mark SiblyKeymaster]

Very cool!

Technically speaking, you’re meant to bracket your GL code (outside of OnRenderGL) calls between BeginGL() and EndGL() or you’ll be affecting the ‘shared’ context, but it seems to be working anyway!

I’ve added a few docs to GLWindow too.

[coconParticipant]

Hi Mark, I don’t know why are there two gl contexts in your design, one for GLWindow and one for Window. Is it mostly for resource organization? Essentially the BeginGL/EndGL performs that swap.

 

Monkey

Method OnRender( canvas:Canvas ) Override BeginGL() OnRenderGL() EndGL() End

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Method OnRender( canvas:Canvas ) Override BeginGL() OnRenderGL() EndGL() End

[Mark SiblyKeymaster]

Hi Mark, I don’t know why are there two gl contexts in your design,

A couple of reasons:

• Since I have no idea what GL states custom non-mojo code is modifying, using a single context would mean mojo would have to push/pop/reset (or do something fancy ) with *ALL* GL state before/after any custom GL code runs. This would involved resetting viewport, framebuffer, texture bindings etc which is slow.
• It allows for the possibility of users creating GL3/GL4 contexts (TODO – might not work).

Essentially the BeginGL/EndGL performs that swap.

Yes, but it only happens inside OnRender(). The constructor is still running in mojo’s GL context. Again, not sure why it’s working (your glClearColor should be affecting the mojo GL context) but it looks like creating a GL context is also making it current. This could be an Angle thing though.

[coconParticipant]

I did not think of that. Indeed you wouldn’t “trust” the user messing with the original context of mojo in case something goes wrong. Nice one!

[coconParticipant]

Now I have created a 3D cube example.

Update 29 Nov 2016: I have fixed some odd problems with the cube and cleaned up the example.The only problem is that I get weird draw Z order in the faces of the cube.
This problem is fixed, I have declared the order of vertices in a proper manner.
The vertex declaration is from a C++ glm example, the matrix math is from OpenTK library.
I switched into using the Monogame math since it’s much lean and clean implementation.

Monkey

#Import "<mojo>" Using std.. Using mojo.. Using gles20.. Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End Function LoadShader:GLuint() Local vertex:String = " uniform mat4 Matrix; attribute vec3 Position; varying vec3 OutColor; void main() { gl_Position = Matrix * vec4(Position, 1); // Higher vertices can be yellow and lower can be red. OutColor = (Position.y < 0.0) ? vec3(1, 0, 0) : vec3(1, 1, 0); } " Local fragment:String = " varying vec3 OutColor; void main() { gl_FragColor = vec4(OutColor, 1); } " Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") Return program End Class Matrix ' Matrix class is based on Monogame math. Private Field data:Float[] = New Float[16] Public Field M11:Float, M12:Float, M13:Float, M14:Float Field M21:Float, M22:Float, M23:Float, M24:Float Field M31:Float, M32:Float, M33:Float, M34:Float Field M41:Float, M42:Float, M43:Float, M44:Float Property ToArray:Float[]() data[0] = M11 data[1] = M12 data[2] = M13 data[3] = M14 data[4] = M21 data[5] = M22 data[6] = M23 data[7] = M24 data[8] = M31 data[9] = M32 data[10] = M33 data[11] = M34 data[12] = M41 data[13] = M42 data[14] = M43 data[15] = M44 Return data End Operator*:Matrix(matrix:Matrix) Local result := New Matrix result.M11 = (Self.M11 * matrix.M11) + (Self.M12 * matrix.M21) + (Self.M13 * matrix.M31) + (Self.M14 * matrix.M41) result.M12 = (Self.M11 * matrix.M12) + (Self.M12 * matrix.M22) + (Self.M13 * matrix.M32) + (Self.M14 * matrix.M42) result.M13 = (Self.M11 * matrix.M13) + (Self.M12 * matrix.M23) + (Self.M13 * matrix.M33) + (Self.M14 * matrix.M43) result.M14 = (Self.M11 * matrix.M14) + (Self.M12 * matrix.M24) + (Self.M13 * matrix.M34) + (Self.M14 * matrix.M44) result.M21 = (Self.M21 * matrix.M11) + (Self.M22 * matrix.M21) + (Self.M23 * matrix.M31) + (Self.M24 * matrix.M41) result.M22 = (Self.M21 * matrix.M12) + (Self.M22 * matrix.M22) + (Self.M23 * matrix.M32) + (Self.M24 * matrix.M42) result.M23 = (Self.M21 * matrix.M13) + (Self.M22 * matrix.M23) + (Self.M23 * matrix.M33) + (Self.M24 * matrix.M43) result.M24 = (Self.M21 * matrix.M14) + (Self.M22 * matrix.M24) + (Self.M23 * matrix.M34) + (Self.M24 * matrix.M44) result.M31 = (Self.M31 * matrix.M11) + (Self.M32 * matrix.M21) + (Self.M33 * matrix.M31) + (Self.M34 * matrix.M41) result.M32 = (Self.M31 * matrix.M12) + (Self.M32 * matrix.M22) + (Self.M33 * matrix.M32) + (Self.M34 * matrix.M42) result.M33 = (Self.M31 * matrix.M13) + (Self.M32 * matrix.M23) + (Self.M33 * matrix.M33) + (Self.M34 * matrix.M43) result.M34 = (Self.M31 * matrix.M14) + (Self.M32 * matrix.M24) + (Self.M33 * matrix.M34) + (Self.M34 * matrix.M44) result.M41 = (Self.M41 * matrix.M11) + (Self.M42 * matrix.M21) + (Self.M43 * matrix.M31) + (Self.M44 * matrix.M41) result.M42 = (Self.M41 * matrix.M12) + (Self.M42 * matrix.M22) + (Self.M43 * matrix.M32) + (Self.M44 * matrix.M42) result.M43 = (Self.M41 * matrix.M13) + (Self.M42 * matrix.M23) + (Self.M43 * matrix.M33) + (Self.M44 * matrix.M43) result.M44 = (Self.M41 * matrix.M14) + (Self.M42 * matrix.M24) + (Self.M43 * matrix.M34) + (Self.M44 * matrix.M44) Return result End Function Identity:Matrix() Local result := New Matrix result.M11 = 1.0 result.M22 = 1.0 result.M33 = 1.0 result.M44 = 1.0 Return result End Function Translation:Matrix(x:Float, y:Float, z:Float) Local result := Identity() result.M41 = x result.M42 = y result.M43 = z Return result End Function RotateX:Matrix(angle:Float) Local cos:Float = Cast<Float>(Cos(angle)) Local sin:Float = Cast<Float>(Sin(angle)) Local result := Identity() result.M22 = cos result.M23 = sin result.M32 = -sin result.M33 = cos Return result End Function RotateY:Matrix(angle:Float) Local cos:Float = Cast<Float>(Cos(angle)) Local sin:Float = Cast<Float>(Sin(angle)) Local result := Identity() result.M11 = cos result.M13 = -sin result.M31 = sin result.M33 = cos Return result End Function Perspective:Matrix(fovy:Float, aspect:Float, near:Float, far:float) Local yMax:Float = near * Tan(0.5 * fovy) Local yMin:Float = -yMax Local xMin:Float = yMin * aspect Local xMax:Float = yMax * aspect Return Frustum(xMin, xMax, yMin, yMax, near, far) End Function Frustum:Matrix(left:Float, right:Float, bottom:Float, top:Float, near:Float, far:Float) Local invRL:Float = 1.0 / (right - left) Local invTB:Float = 1.0 / (top - bottom) Local invFN:Float = 1.0 / (far - near) Local result := New Matrix() result.M11 = 2.0 * near * invRL result.M12 = 0.0 result.M13 = 0.0 result.M14 = 0.0 result.M21 = 0.0 result.M22 = 2.0 * near * invTB result.M23 = 0.0 result.M24 = 0.0 result.M31 = (right + left) * invRL result.M32 = (top + bottom) * invTB result.M33 = -(far + near) * invFN result.M34 = -1.0 result.M41 = 0.0 result.M42 = 0.0 result.M43 = -2.0 * far * near * invFN result.M44 = 0.0 Return result End End Class MyWindow Extends GLWindow Field vbo:GLuint Field ebo:GLuint Field shader:GLuint Field elementsLength:Int Field matrixView:Matrix Field matrixProjection:Matrix Field matrixViewProjection:Matrix Field matrixUniform:Int Method _LoadShader() End Method _LoadVertexBuffer() End Method New() ' enable OpenGL states glClearColor(0.1, 0.1, 0.5, 1.0) glEnable(GL_DEPTH_TEST) glEnable(GL_CULL_FACE) ' define the shape for a cube ' ' 7_________6 ' / / Top vertices ' 4________5 ' ' 3_________2 ' / / Bottom Vertices ' 0________1 Local vertices := New Float[](-1, -1, -1, 1, -1, -1, 1, -1, 1, -1, -1, 1, -1, 1, -1, 1, 1, -1, 1, 1, 1, -1, 1, 1) Local elements := New Int[]( 4, 7, 6, 6, 5, 4, ' Top 0, 1, 2, 2, 3, 0, ' Bottom 0, 3, 7, 7, 4, 0, ' Left 1, 5, 6, 6, 2, 1, ' Right 3, 2, 6, 6, 7, 3, ' Front 0, 4, 5, 5, 1, 0) ' Back elementsLength = elements.Length ' load shader shader = LoadShader() Print("Program ID: " + shader) Print("Attribute Location: " + glGetAttribLocation(shader, "Position")) ' create vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_STATIC_DRAW) ' create element buffer glGenBuffers(1, Varptr ebo) glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo) glBufferData(GL_ELEMENT_ARRAY_BUFFER, elements.Length * 4, elements.Data, GL_STATIC_DRAW) ' create matrix stuff matrixProjection = Matrix.Perspective(Pi / 4.0, Cast<Float>(Width)/Height, 0.5, 100) matrixViewProjection = New Matrix matrixUniform = glGetUniformLocation(shader, "Matrix") End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL", 10, 10) End Method OnRenderGL() Override ' update the view projection matrix matrixView = Matrix.RotateY(App.Millisecs * -0.0005) * Matrix.RotateX(Sin(App.Millisecs*0.0001)) matrixView *= Matrix.Translation(0, 0, -5) matrixViewProjection = matrixView * matrixProjection ' use the shader and update the matrix uniform glUseProgram(shader) glUniformMatrix4fv(matrixUniform, 1, False, matrixViewProjection.ToArray.Data) ' bind the vertex buffer object and enable the vertex attributes glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glVertexAttribPointer(0, 3, GL_FLOAT, False, 0, Cast<Void Ptr>(0)) ' bind the element buffer object glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo) ' finally do the drawing glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) glDrawElements(GL_TRIANGLES, elementsLength, GL_UNSIGNED_INT, Cast<Int Ptr>(0)) End End Function Main() New AppInstance New MyWindow App.Run() End

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#Import "<mojo>" Using std.. Using mojo.. Using gles20..   Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End   Function LoadShader:GLuint() Local vertex:String = " uniform mat4 Matrix; attribute vec3 Position; varying vec3 OutColor; void main() { gl_Position = Matrix * vec4(Position, 1); // Higher vertices can be yellow and lower can be red. OutColor = (Position.y < 0.0) ? vec3(1, 0, 0) : vec3(1, 1, 0); } "   Local fragment:String = " varying vec3 OutColor; void main() { gl_FragColor = vec4(OutColor, 1); } "   Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") Return program End   Class Matrix ' Matrix class is based on Monogame math. Private Field data:Float[] = New Float[16]   Public Field M11:Float, M12:Float, M13:Float, M14:Float Field M21:Float, M22:Float, M23:Float, M24:Float Field M31:Float, M32:Float, M33:Float, M34:Float Field M41:Float, M42:Float, M43:Float, M44:Float   Property ToArray:Float[]() data[0] = M11 data[1] = M12 data[2] = M13 data[3] = M14 data[4] = M21 data[5] = M22 data[6] = M23 data[7] = M24 data[8] = M31 data[9] = M32 data[10] = M33 data[11] = M34 data[12] = M41 data[13] = M42 data[14] = M43 data[15] = M44 Return data End   Operator*:Matrix(matrix:Matrix) Local result := New Matrix   result.M11 = (Self.M11 * matrix.M11) + (Self.M12 * matrix.M21) + (Self.M13 * matrix.M31) + (Self.M14 * matrix.M41) result.M12 = (Self.M11 * matrix.M12) + (Self.M12 * matrix.M22) + (Self.M13 * matrix.M32) + (Self.M14 * matrix.M42) result.M13 = (Self.M11 * matrix.M13) + (Self.M12 * matrix.M23) + (Self.M13 * matrix.M33) + (Self.M14 * matrix.M43) result.M14 = (Self.M11 * matrix.M14) + (Self.M12 * matrix.M24) + (Self.M13 * matrix.M34) + (Self.M14 * matrix.M44)   result.M21 = (Self.M21 * matrix.M11) + (Self.M22 * matrix.M21) + (Self.M23 * matrix.M31) + (Self.M24 * matrix.M41) result.M22 = (Self.M21 * matrix.M12) + (Self.M22 * matrix.M22) + (Self.M23 * matrix.M32) + (Self.M24 * matrix.M42) result.M23 = (Self.M21 * matrix.M13) + (Self.M22 * matrix.M23) + (Self.M23 * matrix.M33) + (Self.M24 * matrix.M43) result.M24 = (Self.M21 * matrix.M14) + (Self.M22 * matrix.M24) + (Self.M23 * matrix.M34) + (Self.M24 * matrix.M44)   result.M31 = (Self.M31 * matrix.M11) + (Self.M32 * matrix.M21) + (Self.M33 * matrix.M31) + (Self.M34 * matrix.M41) result.M32 = (Self.M31 * matrix.M12) + (Self.M32 * matrix.M22) + (Self.M33 * matrix.M32) + (Self.M34 * matrix.M42) result.M33 = (Self.M31 * matrix.M13) + (Self.M32 * matrix.M23) + (Self.M33 * matrix.M33) + (Self.M34 * matrix.M43) result.M34 = (Self.M31 * matrix.M14) + (Self.M32 * matrix.M24) + (Self.M33 * matrix.M34) + (Self.M34 * matrix.M44)   result.M41 = (Self.M41 * matrix.M11) + (Self.M42 * matrix.M21) + (Self.M43 * matrix.M31) + (Self.M44 * matrix.M41) result.M42 = (Self.M41 * matrix.M12) + (Self.M42 * matrix.M22) + (Self.M43 * matrix.M32) + (Self.M44 * matrix.M42) result.M43 = (Self.M41 * matrix.M13) + (Self.M42 * matrix.M23) + (Self.M43 * matrix.M33) + (Self.M44 * matrix.M43) result.M44 = (Self.M41 * matrix.M14) + (Self.M42 * matrix.M24) + (Self.M43 * matrix.M34) + (Self.M44 * matrix.M44)   Return result End   Function Identity:Matrix() Local result := New Matrix result.M11 = 1.0 result.M22 = 1.0 result.M33 = 1.0 result.M44 = 1.0 Return result End Function Translation:Matrix(x:Float, y:Float, z:Float) Local result := Identity() result.M41 = x result.M42 = y result.M43 = z Return result End Function RotateX:Matrix(angle:Float) Local cos:Float = Cast<Float>(Cos(angle)) Local sin:Float = Cast<Float>(Sin(angle))         Local result := Identity() result.M22 = cos result.M23 = sin result.M32 = -sin result.M33 = cos Return result End Function RotateY:Matrix(angle:Float)         Local cos:Float = Cast<Float>(Cos(angle)) Local sin:Float = Cast<Float>(Sin(angle))         Local result := Identity() result.M11 =  cos result.M13 = -sin result.M31 =  sin result.M33 =  cos Return result End   Function Perspective:Matrix(fovy:Float, aspect:Float, near:Float, far:float) Local yMax:Float = near * Tan(0.5 * fovy) Local yMin:Float = -yMax Local xMin:Float = yMin * aspect Local xMax:Float = yMax * aspect Return Frustum(xMin, xMax, yMin, yMax, near, far) End Function Frustum:Matrix(left:Float, right:Float, bottom:Float, top:Float, near:Float, far:Float) Local invRL:Float = 1.0 / (right - left) Local invTB:Float = 1.0 / (top - bottom) Local invFN:Float = 1.0 / (far - near) Local result := New Matrix() result.M11 = 2.0 * near * invRL result.M12 = 0.0 result.M13 = 0.0 result.M14 = 0.0 result.M21 = 0.0 result.M22 = 2.0 * near * invTB result.M23 = 0.0 result.M24 = 0.0 result.M31 = (right + left) * invRL result.M32 = (top + bottom) * invTB result.M33 = -(far + near) * invFN result.M34 = -1.0 result.M41 = 0.0 result.M42 = 0.0 result.M43 = -2.0 * far * near * invFN result.M44 = 0.0 Return result End End   Class MyWindow Extends GLWindow Field vbo:GLuint Field ebo:GLuint Field shader:GLuint Field elementsLength:Int Field matrixView:Matrix Field matrixProjection:Matrix Field matrixViewProjection:Matrix Field matrixUniform:Int Method _LoadShader() End   Method _LoadVertexBuffer() End Method New() ' enable OpenGL states glClearColor(0.1, 0.1, 0.5, 1.0) glEnable(GL_DEPTH_TEST) glEnable(GL_CULL_FACE) ' define the shape for a cube ' '  7_________6 '  /        /    Top vertices ' 4________5 ' '  3_________2 '  /        /    Bottom Vertices ' 0________1 Local vertices := New Float[](-1, -1, -1, 1, -1, -1, 1, -1,  1, -1, -1,  1, -1,  1, -1, 1,  1, -1, 1,  1,  1, -1,  1,  1) Local elements := New Int[]( 4, 7, 6, 6, 5, 4, ' Top 0, 1, 2, 2, 3, 0, ' Bottom 0, 3, 7, 7, 4, 0, ' Left 1, 5, 6, 6, 2, 1, ' Right 3, 2, 6, 6, 7, 3, ' Front 0, 4, 5, 5, 1, 0) ' Back elementsLength = elements.Length ' load shader shader = LoadShader() Print("Program ID: " + shader) Print("Attribute Location: " + glGetAttribLocation(shader, "Position")) ' create vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_STATIC_DRAW) ' create element buffer glGenBuffers(1, Varptr ebo) glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo) glBufferData(GL_ELEMENT_ARRAY_BUFFER, elements.Length * 4, elements.Data, GL_STATIC_DRAW) ' create matrix stuff matrixProjection = Matrix.Perspective(Pi / 4.0, Cast<Float>(Width)/Height, 0.5, 100) matrixViewProjection = New Matrix matrixUniform = glGetUniformLocation(shader, "Matrix") End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL", 10, 10) End Method OnRenderGL() Override ' update the view projection matrix matrixView = Matrix.RotateY(App.Millisecs * -0.0005) * Matrix.RotateX(Sin(App.Millisecs*0.0001)) matrixView *= Matrix.Translation(0, 0, -5) matrixViewProjection = matrixView * matrixProjection ' use the shader and update the matrix uniform glUseProgram(shader) glUniformMatrix4fv(matrixUniform, 1, False, matrixViewProjection.ToArray.Data) ' bind the vertex buffer object and enable the vertex attributes glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glVertexAttribPointer(0, 3, GL_FLOAT, False, 0, Cast<Void Ptr>(0)) ' bind the element buffer object glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo) ' finally do the drawing glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) glDrawElements(GL_TRIANGLES, elementsLength, GL_UNSIGNED_INT, Cast<Int Ptr>(0)) End End   Function Main() New AppInstance New MyWindow App.Run() End

[JesseParticipant]

Nice indeed. Some years Ago I was trying to learn OpenGL so I looked at a few tutorials and started learning it. But with out much luck. At the time I had a project I was working on and didn’t really concentrate on learning it. I did managed to convert a few tutorials from C++ to BlitzMax. When I saw your project, I remembered I had translated a C++ OpenGL cube to Blizmax. I pulled it out and tried to see If I could convert it to Monkey2 GLES but no luck. I don’t know enough about OpenGL to do it. Here is the source and my lousy attempt at converting it to monkey2:

source code with Blitzmax executable:

https://www.dropbox.com/s/x8w95ggaj7tv6bq/texturecube.zip?dl=0

source code Only:

Attachments:

1. texturecube.zip

[coconParticipant]

Nice example, I would try to extract as many useful elements as possible.

Another user in the forums created a cool 3D example with Monkey2, it would be a nice idea to hotlink for easy access.
http://monkey2.monkey-x.com/forums/topic/monkey2-opengl-experiments/#post-5310

Perhaps I will start doing texture loading as well to create a nice snippet and proceed also adding some further abstractions. Like a Mesh class or a Texture class, without going into heavy implementations.

[EdzUpParticipant]

Would it be possible to use OpenGL 1.x with this system, the reason I am wondering is simply MonkeyX2 could actually replace all BRL products. Max and MX1 run with OpenGL 1.x (IIRC 1.4) which would be cool to have a renderer that would cater for these systems as well.

After looking in Currys recently there were several Laptops that had old Intel chips in them that to be honest would be along those lines?

[coconParticipant]

OpenGL 1.x can be used in C and in other languages (I have used C# OpenTK a lot). In Monkey2 theoretically a wrapper could be written to access the OpenGL 1.x library functions. However doing so, would mean that a tremendous good strategy would exist, it’s a huge investment writing for legacy hardware.

[coconParticipant]

After a long time, since I found a chance today I created this little fancy OpenGL example.

Video:
https://1drv.ms/v/s!AquVr9J7xRcsgXYmcIlKcvFD94Lw

It was some code I made a few years ago for OpenTK, now I ported it to Monkey2, I don’t remember where exactly I got the shader from, if you know who made it you can inform me so I can add credits (lots of thanks to the developer if he/she is reading).

Apart from that shader, if you replace the fragment part with any shader from here http://glslsandbox.com/ you could have virtually any GLSL sample available. Keep in mind to the Uniform variables only and some GLSL specifications (there are some differences between GLES and GLSL and you might get errors).

Monkey

#Import "<mojo>" Using std.. Using mojo.. Using gles20.. Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End Function LoadShader:GLuint() Local vertex:String = " attribute vec3 Position; void main() { gl_Position = vec4(Position, 1); } " Local fragment:String = " uniform float time; uniform vec2 mouse; uniform vec2 resolution; #define PI 3.14159 void main( void ) { vec2 p = (gl_FragCoord.xy / resolution.xy ) - 0.5; float sx = 0.2 * (p.x + 0.5) * sin(100.0 * p.x * (mouse.x) - 10.0 * time); float dy = 1.0 / (50. * abs(p.y - sx)); dy += 1./ (50.0 * length(p - vec2(p.x, 0.))); gl_FragColor = vec4((p.x + 0.5) * dy, 0.5 * dy, dy, 1.0); } " Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") Return program End Class MyWindow Extends GLWindow Field vbo:GLuint Field shader:GLuint Field canvas:Canvas Method New() glClearColor(0.1, 0.1, 0.5, 1.0) ' load the shader shader = LoadShader() Print("Program ID: " + shader) Print("Attribute Location ~qPosition~q: " + glGetAttribLocation(shader, "Position")) Print("Uniform Location ~qtime~q: " + glGetUniformLocation(shader, "time")) Print("Uniform Location ~qmouse~q: " + glGetUniformLocation(shader, "mouse")) Print("Uniform Location ~qresolution~q: " + glGetUniformLocation(shader, "resolution")) ' define a quad shape consisted out of two triangles: 0 1 2 , 2 3 0 ' 3-------2 ' | . | ' | . | ' | . | ' 0-------1 Local vertices:Float[] = New Float[](-1,-1,0, 1,-1,0, 1,1,0, -1,-1,0, 1,1,0, -1,1,0) ' create the vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_DYNAMIC_DRAW) End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL Test", 10, 1 * 20) canvas.DrawText("Mouse Location: " + MouseLocation.X, 10, 2 * 20, 0, 0) End Method OnRenderGL() Override ' clear the screen glClear(GL_COLOR_BUFFER_BIT) ' load the shader and update uniforms glUseProgram(shader) glUniform1f(0, Millisecs() * 0.001) glUniform2f(1, Cast<Float>(MouseLocation.X / 500.0), Cast<Float>(MouseLocation.Y)) glUniform2f(2, Cast<Float>(Width), Cast<Float>(Height)) ' bind the buffer, enable vertex attributes glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glVertexAttribPointer(0, 3, GL_FLOAT, False, 0, Cast<Void Ptr>(0)) ' draw the vertex data glDrawArrays(GL_TRIANGLES, 0, 6) End End Function Main() New AppInstance New MyWindow App.Run() End

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#Import "<mojo>"   Using std.. Using mojo.. Using gles20..   Function glLoadProgram:GLuint(vertexSource:String, fragmentSource:String) Local vs := mojo.graphics.glutil.glCompile(GL_VERTEX_SHADER, vertexSource) Local fs := mojo.graphics.glutil. glCompile(GL_FRAGMENT_SHADER, fragmentSource) Local program := glCreateProgram() glAttachShader(program, vs) glAttachShader(program, fs) mojo.graphics.glutil.glLink(program) glDeleteShader(vs) glDeleteShader(fs) Return program End   Function LoadShader:GLuint() Local vertex:String = " attribute vec3 Position; void main() { gl_Position = vec4(Position, 1); } "   Local fragment:String = " uniform float time; uniform vec2 mouse; uniform vec2 resolution;   #define PI 3.14159   void main( void ) { vec2 p = (gl_FragCoord.xy / resolution.xy ) - 0.5; float sx = 0.2 * (p.x + 0.5) * sin(100.0 * p.x * (mouse.x) - 10.0 * time); float dy = 1.0 / (50. * abs(p.y  - sx)); dy += 1./ (50.0  * length(p - vec2(p.x, 0.))); gl_FragColor = vec4((p.x + 0.5) * dy, 0.5 * dy, dy, 1.0); } "   Local program := glLoadProgram(vertex, fragment) glBindAttribLocation(program, 0, "Position") Return program End   Class MyWindow Extends GLWindow Field vbo:GLuint Field shader:GLuint Field canvas:Canvas Method New() glClearColor(0.1, 0.1, 0.5, 1.0) ' load the shader shader = LoadShader() Print("Program ID: " + shader) Print("Attribute Location ~qPosition~q: " + glGetAttribLocation(shader, "Position")) Print("Uniform Location ~qtime~q: " + glGetUniformLocation(shader, "time")) Print("Uniform Location ~qmouse~q: " + glGetUniformLocation(shader, "mouse")) Print("Uniform Location ~qresolution~q: " + glGetUniformLocation(shader, "resolution"))   ' define a quad shape consisted out of two triangles: 0 1 2 , 2 3 0 ' 3-------2 ' |     . | ' |   .   | ' | .     | ' 0-------1 Local vertices:Float[] = New Float[](-1,-1,0,  1,-1,0,  1,1,0,    -1,-1,0,  1,1,0,  -1,1,0)   ' create the vertex buffer glGenBuffers(1, Varptr vbo) glBindBuffer(GL_ARRAY_BUFFER, vbo) glBufferData(GL_ARRAY_BUFFER, vertices.Length * 4, vertices.Data, GL_DYNAMIC_DRAW) End Method OnRender(canvas:mojo.graphics.Canvas) Override App.RequestRender() Super.OnRender(canvas) canvas.DrawText("Monkey2 OpenGL Test", 10, 1 * 20) canvas.DrawText("Mouse Location: " + MouseLocation.X, 10, 2 * 20, 0, 0) End Method OnRenderGL() Override ' clear the screen glClear(GL_COLOR_BUFFER_BIT)   ' load the shader and update uniforms glUseProgram(shader) glUniform1f(0, Millisecs() * 0.001) glUniform2f(1, Cast<Float>(MouseLocation.X / 500.0), Cast<Float>(MouseLocation.Y)) glUniform2f(2, Cast<Float>(Width), Cast<Float>(Height)) ' bind the buffer, enable vertex attributes glBindBuffer(GL_ARRAY_BUFFER, vbo) glEnableVertexAttribArray(0) glVertexAttribPointer(0, 3, GL_FLOAT, False, 0, Cast<Void Ptr>(0))   ' draw the vertex data glDrawArrays(GL_TRIANGLES, 0, 6) End End   Function Main() New AppInstance New MyWindow App.Run() End

[EdzUpParticipant]

very interesting

 

will look into 1.x GL as it would be a nice exercise in working the grey cells

[coconParticipant]

Hi EdzUp, you could jump straight into action and try to do some tutorials. You could use Blitzmax or C++ according to what you feel more comfortable with.

In the exact example, to draw 2 triangles ala GL1 I would simply use these statements: glBegin, glVertex, glEnd. This is the core of all the rendering pipeline (the fixed function pipeline). If you can draw let’s say a triangle, or a colored cube, you can draw and navigate inside a humongous level created with Blender. On the other hand the modern shader based pipeline is much more tricky to get started and understand. There is a need for the perfect combination of these elements before you draw anything: shader, vertex buffer, vertex attributes.

[EdzUpParticipant]

I’ve been coding for some thirty odd years (since ’81 ). I would normally use glDrawElements to render stuff as glBegin etc is convoluted for rendering more complex stuff

[Author]

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