Ray tracing progress: support for lines, markers and text added

great job!

Good morning, guys !

At last month I make some tests of your GLSL code. It's working cool, but your code must be corrected

1. On some cards GLSL program don't working when we use defined constants in function like max, dot . This problem was found on AMD 760G integrated chipset

For example:

vec3 aTrsfInverse = 1.0f / max (abs (aTrsfRay.Direct), vec3(exp2 (-80.0f)));

this code is working on any video cards, but if you are using #define vec3(exp2 (-80.0f)) then we have a problem

2. It some strange with function vec4 Radiance (in SRay theRay, in vec3 theInverse)

you may try to break your loop , but it's don't working . Don't working return, break, continue. The result is strange and may different on various vendors of GPU

Here we need append Post prefix in GLSL program. For example:

// =======================================================================
// function : Radiance
// purpose : Computes color of specified ray
// =======================================================================
vec4 Radiance (in SRay theRay, in vec3 theInverse)
{
vec3 aResult = vec3(0.0f);
vec4 aWeight = vec4(1.0f);

if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); }
if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); } //lines
if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); } //that
if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); } //added in
if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); } //OpenGL_Workspace
if (!ComputeResult(theRay,theInverse,aResult,aWeight)) { return vec4 (aResult,aWeight.w); } //_Raytrace.cxx

return vec4 (aResult,aWeight.w);
}

3. Textured shapes:

vec3 aAmbient;
vec3 aDiffuse;

if (isTexture)
{
vec4 aFinal = uModelProj * vec4(aPoint,1.0f);
aFinal.xyz *= 1.f / aFinal.w;

aFinal.xy = 0.5f * (aFinal.xy - 1.0f);

vec3 myColor = texture(uOpenGlColorTexture, aFinal.xy).rgb;

if (myColor.rgb != vec3(0.0f))
{
aAmbient = myColor;
aDiffuse = myColor*0.25;
}
else
isTexture = false;
}

if (!isTexture)
{
aAmbient = texelFetch (
uRaytraceMaterialTexture, MATERIAL_AMBN (aTriIndex.w)).rgb;
aDiffuse = texelFetch (
uRaytraceMaterialTexture, MATERIAL_DIFF (aTriIndex.w)).rgb;
}

4. Environment map:

if (aTriIndex.x == -1)
{
if (aWeight.w == 0.0f) //Reflection on a shape
{
if (uEnvironmentReflEnable)
{
float aTime = IntersectSphere (theRay, uSceneRadius);
aResult += aWeight.xyz *textureLod (uEnvironmentMapTexture,
Latlong (theRay.Direct * aTime + theRay.Origin, uSceneRadius), 0.0f).xyz;
}
}
else
{
aWeight.w = 0.0f; //Background without transparency

if (uEnvironmentEnable)
{ //Textured background
float aTime = IntersectSphere (theRay, uSceneRadius);
aResult += aWeight.xyz *textureLod (uEnvironmentMapTexture,
Latlong (theRay.Direct * aTime + theRay.Origin, uSceneRadius), 0.0f).xyz;
}
else
{ //White background
aResult = vec3(1.0f,1.0f,1.0f);
}
}
return false;
}

Here is return false. In the fact this is working on any vendors. Because we can't break the loop and result be strange.

5. On some video cards like Intel HD 4000 we have overloaded samplers:

//! Texture buffer of vertex coords.
uniform samplerBuffer uGeometryVertexTexture;
//! Texture buffer of vertex normals.
uniform samplerBuffer uGeometryNormalTexture;
//! Texture buffer of triangle indices.
uniform isamplerBuffer uGeometryTriangTexture;

and some shapes is don't displayed on the screen. At this time I think that this buffers may be are divided ...