tweak line drawing

2012-06-19 17:14:41 +02:00
parent e7c5831302
commit 4d663ca810
3 changed files with 109 additions and 44 deletions
--- a/src/org/mapsforge/android/glrenderer/Shaders.java
+++ b/src/org/mapsforge/android/glrenderer/Shaders.java
@@ -16,26 +16,60 @@
 package org.mapsforge.android.glrenderer;

 class Shaders {
-	final static String gLineVertexShader = "" + "precision mediump float; \n" + "uniform mat4 u_center;"
-			+ "uniform float u_width;" + "attribute vec4 a_position;" + "attribute vec2 a_st;" + "varying vec2 v_st;"
-			+ "void main() {" + "  gl_Position = u_center * a_position;" + "  v_st = a_st;" + "}";
+	final static String gLineVertexShader = ""
+			+ "precision highp float; \n"
+			+ "uniform mat4 u_center;"
+			+ "uniform float u_width;"
+			+ "attribute vec4 a_position;"
+			+ "attribute vec2 a_st;"
+			+ "varying vec2 v_st;"
+			+ "void main() {"
+			+ "  gl_Position = u_center * a_position;"
+			+ "  v_st = a_st;" + "}";

-	final static String gLineFragmentShader = "" + "#extension GL_OES_standard_derivatives : enable\n"
-			+ "precision mediump float;" + "uniform float u_width;" + "uniform int u_mode;" + "uniform vec4 u_color;"
-			+ "const float zero = 0.0;" + "const int standard = 0;" + "const int fixed_width = 2;"
-			+ "varying vec2 v_st;" + "void main() {" + "   gl_FragColor = u_color;" + "   float fuzz = fwidth(v_st.s);"
-			+ "   float len = abs(v_st.s) - u_width;" + "   if (u_mode != fixed_width) {"
-			+ "      if (v_st.t != zero){ " + "         fuzz = max(fuzz, fwidth(v_st.t));"
-			+ "         len = length(v_st) - u_width;" + "      } " +
-			// branching is not recommended...
-			// "      if (- fuzz > len)  " +
-			// "         gl_FragColor = u_color;" +
-			// "       if (len < -fuzz)" +
-			// "         discard;" +
-			// "      else " +
-			"      if (len > -fuzz)" + "         gl_FragColor *= smoothstep(fuzz , -fuzz , len);" + "    } else { " +
-			// just guesswork.. looks ok for fixed line width >= 0.5
-			"      if (len > -fuzz)" + "         gl_FragColor *= smoothstep(fuzz*0.5, -fuzz, len);" + "    }" + "}";
+	final static String gLineFragmentShader = ""
+			+ "#extension GL_OES_standard_derivatives : enable\n"
+			+ "precision mediump float;"
+			+ "uniform float u_width;"
+			+ "uniform int u_mode;"
+			+ "uniform vec4 u_color;"
+			+ "const float zero = 0.0;"
+			+ "const int standard = 0;"
+			+ "const int fixed_width = 2;"
+			+ "const vec4 blank = vec4(1.0, 0.0, 0.0, 1.0);"
+			+ "const vec4 blank2 = vec4(0.0, 1.0, 0.0, 1.0);"
+			+ "varying vec2 v_st;"
+			+ "void main() {"
+			+ "   if (u_mode != fixed_width) {"
+			// + "       gl_FragColor = u_color;"
+			// + "      float fuzz;"
+			// + "      float len;"
+			+ "      if (v_st.t == zero){ "
+			// + "         fuzz = - sqrt(dFdx(v_st.s) * dFdx(v_st.s) + dFdy(v_st.s) * dFdy(v_st.s));"
+			+ "         float fuzz = -fwidth(v_st.s) * 1.5;"
+			+ "          float len = abs(v_st.s) - u_width;"
+			// + "        if (len < fuzz)"
+			+ "         gl_FragColor = u_color * smoothstep(zero, fuzz, len);"
+			+ "      } else {"
+			+ "         float fuzz = -max(fwidth(v_st.s), fwidth(v_st.t)) * 1.5;"
+			+ "         float len = length(v_st) - u_width;"
+			// + "        if (len < fuzz)"
+			+ "         gl_FragColor = u_color * smoothstep(zero, fuzz, len);"
+			+ "      } "
+			// + "      if (len > zero)"
+			// + "         gl_FragColor = blank;"
+			// + "         discard;"
+			// + "         gl_FragColor = u_color;"
+			// + "     else if (len < fuzz)"
+			// + "         gl_FragColor = blank2;"
+			// + "      else "
+			+ "    } else { "
+			+ "      float fuzz = fwidth(v_st.s);"
+			// + "      gl_FragColor = u_color * smoothstep(fuzz, zero, abs(v_st.s) - u_width + fuzz);"
+			// + "         fuzz = - sqrt(dFdx(v_st.s) * dFdx(v_st.s) + dFdy(v_st.s) * dFdy(v_st.s)) * 1.5;"
+			+ "         gl_FragColor = u_color * smoothstep(fuzz*0.5, -fuzz, abs(v_st.s) - u_width);"
+			+ "    }"
+			+ "}";

 	// final static String gLineFragmentShader = "" +
 	// "#extension GL_OES_standard_derivatives : enable\n" +
@@ -48,16 +82,36 @@ class Shaders {
 	// "        gl_FragColor = u_color;" +
 	// "}";

-	final static String gLineFragmentShaderSimple = "" + "precision mediump float;" + "uniform vec4 u_color;"
-			+ "uniform float u_width;" + "varying vec2 v_st;" + "void main() {" + "   vec4 color = u_color;"
-			+ "   float len;" + "   if (v_st.t == 0.0) " + "     len = abs(v_st.s);" + "   else "
-			+ "      len = length(v_st);" + "   if (len > 0.4) {"
-			+ "   color = u_color * (smoothstep(0.2, 1.0, (u_width + 0.3) - len));" + "}" + "    gl_FragColor = color;"
+	final static String gLineFragmentShaderSimple = ""
+			+ "precision mediump float;"
+			+ "uniform vec4 u_color;"
+			+ "uniform float u_width;"
+			+ "varying vec2 v_st;"
+			+ "void main() {"
+			+ "   vec4 color = u_color;"
+			+ "   float len;"
+			+ "   if (v_st.t == 0.0) "
+			+ "     len = abs(v_st.s);"
+			+ "   else "
+			+ "      len = length(v_st);"
+			+ "   if (len > 0.4) {"
+			+ "   color = u_color * (smoothstep(0.2, 1.0, (u_width + 0.3) - len));"
+			+ "}"
+			+ "    gl_FragColor = color;"
 			+ "}";

-	final static String gPolygonVertexShader = "" + "precision mediump float; \n" + "uniform mat4 u_center;\n"
-			+ "attribute vec4 a_position;" + "void main() {" + "  gl_Position = u_center * a_position;" + "}";
+	final static String gPolygonVertexShader = ""
+			+ "precision mediump float; \n"
+			+ "uniform mat4 u_center;\n"
+			+ "attribute vec4 a_position;"
+			+ "void main() {"
+			+ "  gl_Position = u_center * a_position;"
+			+ "}";

-	final static String gPolygonFragmentShader = "" + "precision mediump float;" + "uniform vec4 u_color;"
-			+ "void main() {" + "  gl_FragColor = u_color;" + "}";
+	final static String gPolygonFragmentShader = ""
+			+ "precision mediump float;"
+			+ "uniform vec4 u_color;"
+			+ "void main() {"
+			+ "  gl_FragColor = u_color;"
+			+ "}";
 }