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[yuzi]

GLSL mat4 constructor problem

My GLSL application runs well with nVidia and Intel GPU. But I encountered a problem with Radeon HD5400 and latest drivers on Windows XP SP3.

In a vertex shader, this code does not work correctly.

-----------------------------------------------

void main() 

{

float caz = 1;

float saz = 0;

mat4 Rz = mat4(caz, saz, 0, 0, -saz, caz, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1);

-----------------------------------------------

Instead, this code works correctly.

-----------------------------------------------

void main() 

{

float caz = 1;

float saz = 0;

mat4 Rz = mat4(vec4(caz, saz, 0, 0), vec4(-saz, caz, 0, 0), vec4(0, 0, 1, 0), vec4(0, 0, 0, 1));

-----------------------------------------------

It seems to me that following code behaves almost identically to the first code.

(Note that 3rd row of 4th column is one)

-----------------------------------------------

void main() 

{

float caz = 1;

float saz = 0;

mat4 Rz = mat4(vec4(caz, saz, 0, 0), vec4(-saz, caz, 0, 0), vec4(0, 0, 1, 0), vec4(0, 0, 1, 1));

-----------------------------------------------

I hope this problem will be corrected shortly.

Regards.

[Shrinker]

What exactly are the effects of the problem you are experiencing? All we see are some assignments. Are there any compile error messages?

[yuzi]

Here is original VS code.

No compiler error nor GL error reported.

I narrowed problems and I ended up with mat4 constructor and arithmetic assignments.

-------------------------------

const float kDepthRange = 3.0;

uniform float SizeX;

uniform float SizeY;

uniform float Aspect;

uniform float Divergence;

uniform float RotX, RotY, RotZ;

uniform float PosX, PosY;

void main() 

{

mat4 proj, model, m;

{ // model

// rotation (Y*X*Z)

float a, ca, sa;

// rotation (Y)

a = radians(RotY);

ca = cos(a);

sa = sin(a);

model = mat4(ca, 0, -sa, 0,

0, 1, 0, 0, 

sa, 0, ca, 0, 

0, 0, 0, 1); 

// rotation (X)

a = radians(RotX);

ca = cos(a);

sa = sin(a);

model *= mat4(1, 0, 0, 0,

0, ca, sa, 0, 

0, -sa, ca, 0, 

0, 0, 0, 1); 

// rotation (Z)

a = radians(RotZ);

ca = cos(a);

sa = sin(a);

model *= mat4(ca, sa, 0, 0,

-sa, ca, 0, 0, 

0, 0, 1, 0, 

0, 0, 0, 1); 

}

// projection

if (0.0 < Divergence)

{

float dist = 1.0 / tan(radians(Divergence));

float near = max(dist * 0.1, dist - kDepthRange);

float far = dist + kDepthRange;

// float corner = near / dist;

proj = 

// glFrustum(-corner, corner, -corner, corner, near, distance + kDepthRange);

mat4(dist,0,0,0,

0,dist,0,0,

0,0,-(far+near)/(far-near),-1,

0,0,-2.0*far*near/(far-near),0) *

// glTranslatef(0, 0, -distance);

mat4(1,0,0,0,

0,1,0,0,

0,0,1,0,

0,0,-dist,1);

}

else

{

proj = 

// glScalef(1.0, 1.0, 0.0); // no depth

mat4(1,0,0,0,

0,1,0,0,

0,0,0,0,

0,0,0,1);

}

{

m = 

/* projection aspect

glScalef(1.0f, aspect, 1.0f);

*/

mat4(1,0,0,0,

0,Aspect,0,0,

0,0,1,0,

0,0,0,1) *

/* position */

mat4(1, 0, 0, 0, 

0, 1, 0, 0, 

0, 0, 1, 0, 

PosX, PosY, 0, 1) * 

proj * model * 

/* placement

glScalef(mSizeX, mSizeY, 1);

*/

mat4(SizeX,0,0,0,

0,SizeY,0,0,

0,0,1,0,

0,0,0,1) *

/* model aspect

glScalef(1.0f, 1.0f / aspect, 1.0f);

*/

mat4(1,0,0,0,

0,1.0/Aspect,0,0,

0,0,1,0,

0,0,0,1);

}

gl_Position = m * gl_Vertex;

gl_TexCoord[0] = gl_TextureMatrix[0] * vec4(0.5*(gl_Vertex.x + 1.0), 0.5*(gl_Vertex.y + 1.0), 0, 1);

}

[frali]

It looks to me that Rz[2] is not correct. Thanks for your feedback. We will fix it soon.