FixedFuncPipeline GL_POINTS: Fix gl_PointSize (attribute data format), Add GL_POINT_SOFT and dist/fade attenuation (Adding basic POINT unit tests)

gl_PointSize (and all other uniform array elems) was not propagated due to wrong usage of GLUniformData component param.
Due to efficiency, we use vec4[2] now and #defines in shader to easy readability.

GL_POINT_SOFT uses gl_PointCoord to determnine inside/outside circle position
while adding a seam of 10% in/out. This almost matches 'other' implementations and gives a nice smooth circle.

!GL_POINT_SOFT produces a proper square (billboard).

Point-Vertex shader takes dist/fade attentuation into account.

3 files changed, 56 insertions, 13 deletions

diff --git a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.fp b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.fp
index beca47bc1..6185e96ef 100644
--- a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.fp
+++ b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.fp
@@ -6,11 +6,34 @@
 #include mgl_uniform.glsl
 #include mgl_varying.glsl
 
+// #define TEST 1
+
 void main (void)
 { 
-  // FIXME: Since gl_Points must be 1.0 (otherwise no points)
-  //         don't see reason for fetching texture color.
-  // gl_FragColor = frontColor * texture2D(mgl_Texture0, gl_PointCoord);
   gl_FragColor = frontColor;
+
+  if( pointSmooth > 0.5 ) {
+      // smooth (AA)
+      const float border = 0.90; // take/give 10% for AA
+
+      // origin to 0/0, [-1/-1 .. 1/1]
+      vec2 pointPos = 2.0 * gl_PointCoord - 1.0 ;
+      float r = length( pointPos ); // one-circle sqrt(x * x + y * y), range: in-circle [0..1], out >1
+      float r1 = 1.0 - ( step(border, r) * 10.0 * ( r - border ) ) ; // [0..1]
+      #ifndef TEST
+          if( r1 < 0.0 ) {
+            discard;
+          }
+      #endif
+
+      #ifndef TEST
+          gl_FragColor.a *= r1;
+      #else
+          gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
+          gl_FragColor.r = r1 < 0.0 ? 1.0 : 0.0;
+          gl_FragColor.g = r > 1.0 ? 1.0 : 0.0;
+          gl_FragColor.b = r > border ? 1.0 : 0.0;
+      #endif
+  }
 }
 
diff --git a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.vp b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.vp
index 6d6a3a982..64732dc9e 100644
--- a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.vp
+++ b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/FixedFuncPoints.vp
@@ -9,17 +9,26 @@
 
 void main(void)
 {
-  if(mgl_ColorEnabled>0) {
-    frontColor=mgl_Color;
+  if( mgl_ColorEnabled > 0 ) {
+    frontColor = mgl_Color;
   } else {
-    frontColor=mgl_ColorStatic;
+    frontColor = mgl_ColorStatic;
   }
 
-  // FIXME: ES2 .. doesn't work, but even on desktop 
-  //        no big points!
-  // gl_PointSize = mgl_PointParams1[0];
-  gl_PointSize = 1.0;
+  vec4 eyeCoord = mgl_PMVMatrix[1] * mgl_Vertex;
+  gl_Position = mgl_PMVMatrix[0] * eyeCoord;
 
-  gl_Position = mgl_PMVMatrix[0] * mgl_PMVMatrix[1] * vec4(mgl_Vertex.xyz, 1.0);
+  float dist = distance(eyeCoord, vec4(0.0, 0.0, 0.0, 1.0));
+  float atten = sqrt( 1.0 / ( pointDistanceConstantAtten +
+                              ( pointDistanceLinearAtten +
+                                pointDistanceQuadraticAtten * dist
+                              ) * dist
+                            )
+                    );
+  float size = clamp(pointSize * atten, pointSizeMin, pointSizeMax);
+  gl_PointSize = max(size, pointFadeThresholdSize);
+
+  float fade = min(size, pointFadeThresholdSize) / pointFadeThresholdSize;
+  frontColor.a *= fade * fade;
 }
 
diff --git a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/mgl_uniform.glsl b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/mgl_uniform.glsl
index fd24a953d..5029e4bd8 100644
--- a/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/mgl_uniform.glsl
+++ b/src/jogl/classes/jogamp/opengl/util/glsl/fixedfunc/shaders/mgl_uniform.glsl
@@ -11,8 +11,19 @@ uniform LOWP    int     mgl_ColorEnabled;
 uniform         vec4    mgl_ColorStatic;
 uniform LOWP    int     mgl_AlphaTestFunc;
 uniform         float   mgl_AlphaTestRef;
-uniform MEDIUMP float   mgl_PointParams1[4]; // sz, smooth, attnMinSz, attnMaxSz
-uniform MEDIUMP float   mgl_PointParams2[4]; // attnCoeff(3), attnAlphaTs
+
+// [0].rgba: size, smooth, attnMinSz, attnMaxSz
+// [1].rgba: attnCoeff(3), attnFadeTs
+uniform MEDIUMP vec4    mgl_PointParams[2];
+
+#define pointSize                   (mgl_PointParams[0].r)
+#define pointSmooth                 (mgl_PointParams[0].g)
+#define pointSizeMin                (mgl_PointParams[0].b)
+#define pointSizeMax                (mgl_PointParams[0].a)
+#define pointDistanceConstantAtten  (mgl_PointParams[1].r)
+#define pointDistanceLinearAtten    (mgl_PointParams[1].g)
+#define pointDistanceQuadraticAtten (mgl_PointParams[1].b)
+#define pointFadeThresholdSize      (mgl_PointParams[1].a)
 
 // uniform LOWP int    mgl_CullFace; // ES2 supports CullFace implicit ..
 #if MAX_TEXTURE_UNITS > 0