puts "========"
puts "Test custom uniform variables: -vec2, -vec3, -vec4, -mat3, -mat4"
puts "========"

pload MODELING VISUALIZATION

# draw a box
box b 1 2 3
vclear
vclose ALL
vinit View1
vsetdispmode 1
vaxo
vdisplay b
vfit
vrotate 0.2 0.0 0.0

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

# vertex shader applying a mat4 uniform transform and passing a vec4 color to fragment
set aShaderVert "
uniform mat4  uModelTrsf;
uniform mat3  uNormTrsf;
uniform vec4  uColor;
uniform vec3  uLightDir;
uniform vec2  uScale;
THE_SHADER_OUT vec4  vColor;
THE_SHADER_OUT vec3  vNormal;
void main() {
  vec4 aPos = uModelTrsf * occVertex;
  aPos.xy  *= uScale;
  vNormal   = normalize(uNormTrsf * occNormal.xyz);
  vColor    = uColor;
  gl_Position = occProjectionMatrix * occWorldViewMatrix * aPos;
}"

# fragment shader using the passed color and simple diffuse lighting
set aShaderFrag "
uniform vec3 uLightDir;
THE_SHADER_IN vec4 vColor;
THE_SHADER_IN vec3 vNormal;
void main() {
  float aNdotL = max(dot(normalize(vNormal), normalize(uLightDir)), 0.2);
  occSetFragColor(vec4(vColor.rgb * aNdotL, vColor.a));
}"

# identity mat4 (row-major: 1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1)
# identity mat3 (row-major: 1 0 0  0 1 0  0 0 1)
vshaderprog b -vert $aShaderVert -frag $aShaderFrag -header "$aGlslVer" \
  -mat4  uModelTrsf 1 0 0 0  0 1 0 0  0 0 1 0  0 0 0 1 \
  -mat3  uNormTrsf  1 0 0  0 1 0  0 0 1 \
  -vec4  uColor     0.2 0.6 1.0 1.0 \
  -vec3  uLightDir  0.0 0.0 1.0 \
  -vec2  uScale     1.0 1.0
vdump $::imagedir/${::casename}_identity.png

# apply a non-identity mat4 (translation by 0.5 in X)
vshaderprog b -vert $aShaderVert -frag $aShaderFrag -header "$aGlslVer" \
  -mat4  uModelTrsf 1 0 0 0.5  0 1 0 0  0 0 1 0  0 0 0 1 \
  -mat3  uNormTrsf  1 0 0  0 1 0  0 0 1 \
  -vec4  uColor     1.0 0.4 0.2 1.0 \
  -vec3  uLightDir  1.0 1.0 1.0 \
  -vec2  uScale     0.8 0.8
vdump $::imagedir/${::casename}_translated.png