Need help porting open gl to direct x shader code

[rohezal]

I wrote for an university projet some shader code in gl sl which I want to port in hl sl. Maybe someone on this board can help me a bit

http://www.gamedev.net/topic/646880-problem-to-port-gl-sl-shader-to-hlsl/

 

[Pickle]

Some things you might need to consider is that the coordinate system is different, color order is reversed.

 

[rohezal]

The coordinate system is the problem . I want to get the angle between the camera and the quad. Then rotate it (works) and show a different texture depending on the viewing angle. In open gl it works but the texture are wrong in direct x.

 

[Pickle]

I worked around this in hurrican using the CML library it has API that creates the matrix needed either for either coordinate system, maybe this works for you too.

Edit:

So i was going from D3D to OpenGL and i used:

cml::matrix_orthographic_RH( matProj, 0.0f, (float)SCREENWIDTH, (float)SCREENHEIGHT, 0.0f, 0.0f, 1.0f, cml::z_clip_neg_one );

 

http://cmldev.net/?p=189

 

I think you would want to use something like matrix_perspective_LH

 

[crow_riot]

do you have any screenshots at hand? it'd be easier to actually SEE whats wrong than looking at the code

just guessing, dont know atm but you might want to try to use the transpose of the rotMatrixZ? (swap row with column, but i think you know that?)

 

[rohezal]

Yes I already change the matrix. The first step is, to create a quad rotates toward the camera. Like a tree image which faces always the player.

The second step is to show a image from back of the tree when the players sees the back of the tree. And a picture of the front of the tree when the player sees the front.

To archive this I have 16x4 images in one texture, calculate which image I want to display on the quad and show it. open gl no problem.

Direct X shows one image, then 2 images at once, then 4 and so on.

 

[crow_riot]

hm ... are you using the correct vertices to calculate the angle? and are you writing the correct UVs ? you know usually opengl has Y-up and directx Z-up ... and when you start to see more it means that on one corner, you're not calculating the angle correctly letting teh TexCoord0.x/y at 0.

 

[rohezal]

I dont have the source code I can just use the shader code. In open gl the object center is 0,0,0, the same in direct x or? the rotation of the object works, but the calculation of the image i want to show is not. I can't print the angle and other debug infos . Maybe somewhere in the calculation from sin and cos to 360° is something wrong. Do you a formular to calc a degree from sin and cos?

 

[Pickle]

Heres a site I used to understand the D3D side, this might not help since its D3D 9 and nothing about HLSL:

http://www.toymaker.info/Games/html/matrices.html

I remembered another difference between the opengl and d3d, opengl combines the view and world matrices, but D3D separates them.

 

[rohezal]

Explained the problem a bit better: http://www.gamedev.net/topic/646880-problem-to-port-gl-sl-shader-to-hlsl/