char osgText_Text_frag[] = "$OSG_GLSL_VERSION\n" "\n" "#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE)\n" "#pragma import_defines( SIGNED_DISTANCE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)\n" "\n" "#ifdef GL_ES\n" " #extension GL_OES_standard_derivatives : enable\n" " #ifndef GL_OES_standard_derivatives\n" " #undef SIGNED_DISTANCE_FIELD\n" " #endif\n" "#endif\n" "\n" "#if !defined(GL_ES)\n" " #if __VERSION__>=400\n" " #define osg_TextureQueryLOD textureQueryLod\n" " #else\n" " #extension GL_ARB_texture_query_lod : enable\n" " #ifdef GL_ARB_texture_query_lod\n" " #define osg_TextureQueryLOD textureQueryLOD\n" " #endif\n" " #endif\n" "#endif\n" "\n" "#if __VERSION__>=130\n" " #define TEXTURE texture\n" "#else\n" " #define TEXTURE texture2D\n" "#endif\n" "\n" "#if __VERSION__>=130\n" " #define TEXTURELOD textureLod\n" "#else\n" " #ifdef GL_ES\n" " #extension GL_EXT_shader_texture_lod : enable\n" " #ifdef GL_EXT_shader_texture_lod\n" " #define TEXTURELOD texture2DLodEXT\n" " #else\n" " #define TEXTURELOD texture2DLod\n" " #endif\n" " #else\n" " #define TEXTURELOD texture2DLod\n" " #endif\n" "#endif\n" "\n" "#if !defined(GL_ES) && __VERSION__>=130\n" " #define ALPHA r\n" " #define SDF g\n" "#else\n" " #define ALPHA a\n" " #define SDF r\n" "#endif\n" "\n" "$OSG_PRECISION_FLOAT\n" "\n" "#if __VERSION__>=130\n" " out vec4 osg_FragColor;\n" "#else\n" " #define osg_FragColor gl_FragColor\n" "#endif\n" "\n" "uniform sampler2D glyphTexture;\n" "\n" "$OSG_VARYING_IN vec2 texCoord;\n" "$OSG_VARYING_IN vec4 vertexColor;\n" "\n" "#ifndef TEXTURE_DIMENSION\n" "const float TEXTURE_DIMENSION = 1024.0;\n" "#endif\n" "\n" "#ifndef GLYPH_DIMENSION\n" "const float GLYPH_DIMENSION = 32.0;\n" "#endif\n" "\n" "#ifdef SIGNED_DISTANCE_FIELD\n" "\n" "float distanceFromEdge(vec2 tc)\n" "{\n" " float center_alpha = TEXTURELOD(glyphTexture, tc, 0.0).SDF;\n" " if (center_alpha==0.0) return -1.0;\n" "\n" " //float distance_scale = (1.0/4.0)*1.41;\n" " float distance_scale = (1.0/6.0)*1.41;\n" " //float distance_scale = (1.0/8.0)*1.41;\n" "\n" " return (center_alpha-0.5)*distance_scale;\n" "}\n" "\n" "#ifdef OUTLINE\n" "vec2 colorCoeff(float edge_distance, float blend_width, float blend_half_width)\n" "{\n" " float outline_width = OUTLINE*0.5;\n" " if (edge_distance>blend_half_width)\n" " {\n" " return vec2(1.0, 0.0);\n" " }\n" " else if (edge_distance>-blend_half_width)\n" " {\n" " float f = smoothstep(0.0, 1.0, (blend_half_width-edge_distance)/(blend_width));\n" " return vec2(1.0 - f, f);\n" " }\n" " else if (edge_distance>(blend_half_width-outline_width))\n" " {\n" " return vec2(0.0, 1.0);\n" " }\n" " else if (edge_distance>-(outline_width+blend_half_width))\n" " {\n" " return vec2(0.0, smoothstep(0.0, 1.0, (blend_half_width+outline_width+edge_distance)/blend_width));\n" " }\n" " else\n" " {\n" " return vec2(0.0, 0.0);\n" " }\n" "}\n" "#else\n" "float colorCoeff(float edge_distance, float blend_width, float blend_half_width)\n" "{\n" " if (edge_distance>blend_half_width)\n" " {\n" " return 1.0;\n" " }\n" " else if (edge_distance>-blend_half_width)\n" " {\n" " return smoothstep(1.0, 0.0, (blend_half_width-edge_distance)/(blend_width));\n" " }\n" " else\n" " {\n" " return 0.0;\n" " }\n" "}\n" "#endif\n" "\n" "vec4 textColor(vec2 src_texCoord)\n" "{\n" " float sample_distance_scale = 0.75;\n" " vec2 dx = dFdx(src_texCoord)*sample_distance_scale;\n" " vec2 dy = dFdy(src_texCoord)*sample_distance_scale;\n" "\n" "\n" " float distance_across_pixel = length(dx+dy)*(TEXTURE_DIMENSION/GLYPH_DIMENSION);\n" "\n" " // compute the appropriate number of samples required to avoid aliasing.\n" " int maxNumSamplesAcrossSide = 4;\n" "\n" " int numSamplesX = int(TEXTURE_DIMENSION * length(dx));\n" " int numSamplesY = int(TEXTURE_DIMENSION * length(dy));\n" " if (numSamplesX<2) numSamplesX = 2;\n" " if (numSamplesY<2) numSamplesY = 2;\n" " if (numSamplesX>maxNumSamplesAcrossSide) numSamplesX = maxNumSamplesAcrossSide;\n" " if (numSamplesY>maxNumSamplesAcrossSide) numSamplesY = maxNumSamplesAcrossSide;\n" "\n" "\n" " vec2 delta_tx = dx/float(numSamplesX-1);\n" " vec2 delta_ty = dy/float(numSamplesY-1);\n" "\n" " float numSamples = float(numSamplesX)*float(numSamplesY);\n" " float blend_width = 1.5*distance_across_pixel/numSamples;\n" " float blend_half_width = blend_width*0.5;\n" "\n" " // check whether fragment is wholly within or outwith glyph body+outline\n" " float cd = distanceFromEdge(src_texCoord); // central distance (distance from center to edge)\n" " if (cd-blend_half_width>distance_across_pixel) return vertexColor; // pixel fully within glyph body\n" "\n" " #ifdef OUTLINE\n" " float outline_width = OUTLINE*0.5;\n" " if ((-cd-outline_width-blend_half_width)>distance_across_pixel) return vec4(0.0, 0.0, 0.0, 0.0); // pixel fully outside outline+glyph body\n" " vec2 color_coeff = vec2(0.0, 0.0);\n" " #else\n" " if (-cd-blend_half_width>distance_across_pixel) return vec4(0.0, 0.0, 0.0, 0.0); // pixel fully outside glyph body\n" " float color_coeff = 0.0;\n" " #endif\n" "\n" " // use multi-sampling to provide high quality antialised fragments\n" " vec2 origin = src_texCoord - dx*0.5 - dy*0.5;\n" " for(;numSamplesY>0; --numSamplesY)\n" " {\n" " vec2 pos = origin;\n" " int numX = numSamplesX;\n" " for(;numX>0; --numX)\n" " {\n" " #ifdef OUTLINE\n" " color_coeff += colorCoeff(distanceFromEdge(pos), blend_width, blend_half_width);\n" " #else\n" " color_coeff += colorCoeff(distanceFromEdge(pos), blend_width, blend_half_width);\n" " #endif\n" " pos += delta_tx;\n" " }\n" " origin += delta_ty;\n" " }\n" " color_coeff /= numSamples;\n" " \n" " #ifdef OUTLINE\n" " float vertex_alpha = vertexColor.a * color_coeff.x;\n" " float outline_alpha = BACKDROP_COLOR.a * color_coeff.y;\n" " float total_alpha = vertex_alpha + outline_alpha;\n" "\n" " if (total_alpha <= 0.0) return vec4(0.0, 0.0, 0.0, 0.0);\n" "\n" " return vec4(vertexColor.rgb * (vertex_alpha / total_alpha) + BACKDROP_COLOR.rgb * (outline_alpha / total_alpha), total_alpha);\n" " #else\n" " return vec4(vertexColor.rgb, vertexColor.a * color_coeff);\n" " #endif\n" "}\n" "\n" "#else\n" "\n" "vec4 textColor(vec2 src_texCoord)\n" "{\n" "\n" "#ifdef OUTLINE\n" "\n" " float alpha = TEXTURE(glyphTexture, src_texCoord).ALPHA;\n" " float delta_tc = 1.6*OUTLINE*GLYPH_DIMENSION/TEXTURE_DIMENSION;\n" "\n" " float outline_alpha = alpha;\n" " vec2 origin = src_texCoord-vec2(delta_tc*0.5, delta_tc*0.5);\n" "\n" " float numSamples = 3.0;\n" " delta_tc = delta_tc/(numSamples-1.0);\n" "\n" " float background_alpha = 1.0;\n" "\n" " for(float i=0.0; i1.0) outline_alpha = 1.0;\n" "\n" " if (outline_alpha==0.0) return vec4(0.0, 0.0, 0.0, 0.0); // outside glyph and outline\n" "\n" " vec4 color = mix(BACKDROP_COLOR, vertexColor, smoothstep(0.0, 1.0, alpha));\n" " color.a = vertexColor.a * smoothstep(0.0, 1.0, outline_alpha);\n" "\n" " return color;\n" "\n" "#else\n" "\n" " float alpha = TEXTURE(glyphTexture, src_texCoord).ALPHA;\n" " if (alpha==0.0) vec4(0.0, 0.0, 0.0, 0.0);\n" " return vec4(vertexColor.rgb, vertexColor.a * alpha);\n" "\n" "#endif\n" "}\n" "\n" "#endif\n" "\n" "\n" "void main(void)\n" "{\n" " if (texCoord.x<0.0 && texCoord.y<0.0)\n" " {\n" " osg_FragColor = vertexColor;\n" " return;\n" " }\n" "\n" "#ifdef SHADOW\n" " float scale = -1.0*GLYPH_DIMENSION/TEXTURE_DIMENSION;\n" " vec2 delta_tc = SHADOW*scale;\n" " vec4 shadow_color = textColor(texCoord+delta_tc);\n" " shadow_color.rgb = BACKDROP_COLOR.rgb;\n" "\n" " vec4 glyph_color = textColor(texCoord);\n" "\n" " // lower the alpha_power value the greater the staturation, no need to be so aggressive with SDF than GREYSCALE\n" " #if SIGNED_DISTANCE_FIELD\n" " float alpha_power = 0.6;\n" " #else\n" " float alpha_power = 0.5;\n" " #endif\n" "\n" " // over saturate the alpha values to make sure the font and it's shadow are clear\n" " shadow_color.a = pow(shadow_color.a, alpha_power);\n" " glyph_color.a = pow(glyph_color.a, alpha_power);\n" " vec4 color = mix(shadow_color, glyph_color, glyph_color.a);\n" "\n" "#else\n" " vec4 color = textColor(texCoord);\n" "#endif\n" "\n" " if (color.a==0.0) discard;\n" "\n" " osg_FragColor = color;\n" "}\n" "\n";