puts "========"
puts "0032862: Visualization, Graphic3d_TextureMap - add 3D texture definition"
puts "========"

pload MODELING VISUALIZATION

set aTex1 [locate_data_file SF_CubeMap_posx.jpg]
set aTex2 [locate_data_file SF_CubeMap_negx.jpg]
set aTex3 [locate_data_file SF_CubeMap_posy.jpg]
set aTex4 [locate_data_file SF_CubeMap_negy.jpg]
set aTex5 [locate_data_file SF_CubeMap_posz.jpg]
set aTex6 [locate_data_file SF_CubeMap_negz.jpg]

set aShaderVert "
THE_SHADER_OUT vec3 TexCoord;
uniform float uSlice;
void main() {
  float aNbSlices = 6.0;
  TexCoord = occVertex.xyz;
  if (uSlice >= 0.0) { TexCoord = vec3(occTexCoord.xy, uSlice * 1.0 / aNbSlices + 0.5 / aNbSlices); }
  if (occTextureTrsf_Scale().y < 0.0) { TexCoord.y = 1.0 - TexCoord.y; }
  gl_Position = occProjectionMatrix * occWorldViewMatrix * occModelWorldMatrix * occVertex;
}"

set aShaderFrag "
#ifdef GL_ES
  uniform mediump sampler3D occSampler0;
#else
  uniform sampler3D occSampler0;
#endif
THE_SHADER_IN vec3 TexCoord;
void main() {
  occFragColor = occTexture3D(occSampler0, TexCoord);
}"

set aGlslVer "#version 110"
if { [vdriver -default] == "TKOpenGles" } { set aGlslVer "#version 300 es" }

# draw a box
box b 1.0 1.0 1.0
vclear
vclose ALL
vinit View1
vaxo
vdisplay -dispMode 1 b
vfit
vrotate 0.2 0.0 0.0

# load 3D texture
vtexture b -3d $aTex1 $aTex2 $aTex3 $aTex4 $aTex5 $aTex6

# texture slices
foreach aSliceIter {0 1 2 3 4 5} {
  vshaderprog b -vert $aShaderVert -frag $aShaderFrag -defaultSampler 0 -uniform "uSlice" ${aSliceIter} -header "$aGlslVer"
  vdump $::imagedir/${::casename}_s${aSliceIter}.png
}

# texture interpolation
vshaderprog b -vert $aShaderVert -frag $aShaderFrag -defaultSampler 0 -uniform "uSlice" -1 -header "$aGlslVer"
vdump $::imagedir/${::casename}_def.png