Renamed text_sdf.frag to text.frag and removed text_greyscale_frag.

Cleaned up setup of osgText::ShaderTechnique adding a NO_SHADER_TECHNIQUE option.
This commit is contained in:
Robert Osfield 2017-10-23 16:07:24 +01:00
parent 4b295c46d1
commit 55a1764712
6 changed files with 272 additions and 317 deletions

View File

@ -40,6 +40,7 @@ class GlyphTexture;
enum ShaderTechnique enum ShaderTechnique
{ {
NO_TEXT_SHADER = 0x0,
GREYSCALE = 0x1, GREYSCALE = 0x1,
SIGNED_DISTANCE_FIELD = 0x2, SIGNED_DISTANCE_FIELD = 0x2,
ALL_FEATURES = GREYSCALE | SIGNED_DISTANCE_FIELD ALL_FEATURES = GREYSCALE | SIGNED_DISTANCE_FIELD

View File

@ -173,7 +173,7 @@ void GlyphTexture::copyGlyphImage(Glyph* glyph, Glyph::TextureInfo* info)
{ {
_image->dirty(); _image->dirty();
if (_shaderTechnique==GREYSCALE) if (_shaderTechnique<=GREYSCALE)
{ {
// OSG_NOTICE<<"GlyphTexture::copyGlyphImage() greyscale copying. glyphTexture="<<this<<", glyph="<<glyph->getGlyphCode()<<std::endl; // OSG_NOTICE<<"GlyphTexture::copyGlyphImage() greyscale copying. glyphTexture="<<this<<", glyph="<<glyph->getGlyphCode()<<std::endl;
// make sure the glyph image settings and the target image are consisent before copying. // make sure the glyph image settings and the target image are consisent before copying.
@ -414,22 +414,13 @@ osg::Image* GlyphTexture::createImage()
_image = new osg::Image; _image = new osg::Image;
GLenum imageFormat = (_shaderTechnique==GREYSCALE) ? OSGTEXT_GLYPH_ALPHA_FORMAT : OSGTEXT_GLYPH_SDF_FORMAT; GLenum imageFormat = (_shaderTechnique<=GREYSCALE) ? OSGTEXT_GLYPH_ALPHA_FORMAT : OSGTEXT_GLYPH_SDF_FORMAT;
GLenum internalFormat = (_shaderTechnique==GREYSCALE) ? OSGTEXT_GLYPH_ALPHA_INTERNALFORMAT : OSGTEXT_GLYPH_SDF_INTERNALFORMAT; GLenum internalFormat = (_shaderTechnique<=GREYSCALE) ? OSGTEXT_GLYPH_ALPHA_INTERNALFORMAT : OSGTEXT_GLYPH_SDF_INTERNALFORMAT;
_image->allocateImage(getTextureWidth(), getTextureHeight(), 1, imageFormat, GL_UNSIGNED_BYTE); _image->allocateImage(getTextureWidth(), getTextureHeight(), 1, imageFormat, GL_UNSIGNED_BYTE);
_image->setInternalTextureFormat(internalFormat); _image->setInternalTextureFormat(internalFormat);
memset(_image->data(), 0, _image->getTotalSizeInBytes()); memset(_image->data(), 0, _image->getTotalSizeInBytes());
for(GlyphRefList::iterator itr = _glyphs.begin();
itr != _glyphs.end();
++itr)
{
Glyph* glyph = itr->get();
// copyGlyphImage(glyph); // TODO!!!!!
OSG_NOTICE<<"GlyphTexture::createImage() need to implement copy"<<std::endl;
}
} }
return _image.get(); return _image.get();

View File

@ -56,6 +56,10 @@ Text::Text():
{ {
_shaderTechnique = GREYSCALE; _shaderTechnique = GREYSCALE;
} }
else if ((ptr = getenv("OSG_NO_TEXT_SHADER")) != 0)
{
_shaderTechnique = NO_TEXT_SHADER;
}
assignStateSet(); assignStateSet();
} }
@ -139,7 +143,6 @@ osg::StateSet* Text::createStateSet()
} }
} }
if (_shaderTechnique!=GREYSCALE)
{ {
ss<<std::fixed<<std::setprecision(1); ss<<std::fixed<<std::setprecision(1);
@ -151,7 +154,10 @@ osg::StateSet* Text::createStateSet()
ss.str(""); ss.str("");
ss << float(activeFont->getTextureWidthHint()); ss << float(activeFont->getTextureWidthHint());
defineList["TEXTURE_DIMENSION"] = osg::StateSet::DefinePair(ss.str(), osg::StateAttribute::ON); defineList["TEXTURE_DIMENSION"] = osg::StateSet::DefinePair(ss.str(), osg::StateAttribute::ON);
}
if (_shaderTechnique>GREYSCALE)
{
defineList["SIGNED_DISTNACE_FIELD"] = osg::StateSet::DefinePair("1", osg::StateAttribute::ON); defineList["SIGNED_DISTNACE_FIELD"] = osg::StateSet::DefinePair("1", osg::StateAttribute::ON);
} }
@ -200,7 +206,7 @@ osg::StateSet* Text::createStateSet()
#if defined(OSG_GL_FIXED_FUNCTION_AVAILABLE) #if defined(OSG_GL_FIXED_FUNCTION_AVAILABLE)
osg::DisplaySettings::ShaderHint shaderHint = osg::DisplaySettings::instance()->getShaderHint(); osg::DisplaySettings::ShaderHint shaderHint = osg::DisplaySettings::instance()->getShaderHint();
if (_shaderTechnique==GREYSCALE && shaderHint==osg::DisplaySettings::SHADER_NONE) if (_shaderTechnique==NO_TEXT_SHADER && shaderHint==osg::DisplaySettings::SHADER_NONE)
{ {
OSG_NOTICE<<"Font::Font() Fixed function pipeline"<<std::endl; OSG_NOTICE<<"Font::Font() Fixed function pipeline"<<std::endl;
@ -222,19 +228,11 @@ osg::StateSet* Text::createStateSet()
program->addShader(osgDB::readRefShaderFileWithFallback(osg::Shader::VERTEX, "shaders/text.vert", text_vert)); program->addShader(osgDB::readRefShaderFileWithFallback(osg::Shader::VERTEX, "shaders/text.vert", text_vert));
} }
if (_shaderTechnique==GREYSCALE)
{ {
OSG_NOTICE<<"Using shaders/text_greyscale.frag"<<std::endl; OSG_NOTICE<<"Using shaders/text.frag"<<std::endl;
#include "shaders/text_greyscale_frag.cpp" #include "shaders/text_frag.cpp"
program->addShader(osgDB::readRefShaderFileWithFallback(osg::Shader::FRAGMENT, "shaders/text_greyscale.frag", text_greyscale_frag)); program->addShader(osgDB::readRefShaderFileWithFallback(osg::Shader::FRAGMENT, "shaders/text.frag", text_frag));
}
else
{
OSG_NOTICE<<"Using shaders/text_sdf.frag"<<std::endl;
#include "shaders/text_sdf_frag.cpp"
program->addShader(osgDB::readRefShaderFileWithFallback(osg::Shader::FRAGMENT, "shaders/text_sdf.frag", text_sdf_frag));
} }
return stateset.release(); return stateset.release();

View File

@ -0,0 +1,257 @@
char text_frag[] = "$OSG_GLSL_VERSION\n"
"\n"
"#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE, SIGNED_DISTNACE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)\n"
"\n"
"#ifdef GL_ES\n"
" #extension GL_OES_standard_derivatives : enable\n"
" #ifndef GL_OES_standard_derivatives\n"
" #undef SIGNED_DISTNACE_FIELD\n"
" #endif\n"
"#endif\n"
"\n"
"#if !defined(GL_ES)\n"
" #if __VERSION__>=400\n"
" #define osg_TextureQueryLOD textureQueryLod\n"
" #else\n"
" #extension GL_ARB_texture_query_lod : enable\n"
" #ifdef GL_ARB_texture_query_lod\n"
" #define osg_TextureQueryLOD textureQueryLOD\n"
" #endif\n"
" #endif\n"
"#endif\n"
"\n"
"$OSG_PRECISION_FLOAT\n"
"\n"
"#if __VERSION__>=130\n"
" #define TEXTURE texture\n"
" #define TEXTURELOD textureLod\n"
" out vec4 osg_FragColor;\n"
"#else\n"
" #define TEXTURE texture2D\n"
" #define TEXTURELOD texture2DLod\n"
" #define osg_FragColor gl_FragColor\n"
"#endif\n"
"\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"
"\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_DISTNACE_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"
"vec4 distanceFieldColorSample(float edge_distance, float blend_width, float blend_half_width)\n"
"{\n"
"#ifdef OUTLINE\n"
" float outline_width = OUTLINE*0.5;\n"
" if (edge_distance>blend_half_width)\n"
" {\n"
" return vertexColor;\n"
" }\n"
" else if (edge_distance>-blend_half_width)\n"
" {\n"
" return mix(vertexColor, BACKDROP_COLOR, smoothstep(0.0, 1.0, (blend_half_width-edge_distance)/(blend_width)));\n"
" }\n"
" else if (edge_distance>(blend_half_width-outline_width))\n"
" {\n"
" return BACKDROP_COLOR;\n"
" }\n"
" else if (edge_distance>-(outline_width+blend_half_width))\n"
" {\n"
" return vec4(BACKDROP_COLOR.rgb, ((blend_half_width+outline_width+edge_distance)/blend_width));\n"
" }\n"
" else\n"
" {\n"
" return vec4(0.0, 0.0, 0.0, 0.0);\n"
" }\n"
"#else\n"
" if (edge_distance>blend_half_width)\n"
" {\n"
" return vertexColor;\n"
" }\n"
" else if (edge_distance>-blend_half_width)\n"
" {\n"
" return vec4(vertexColor.rgb, smoothstep(1.0, 0.0, (blend_half_width-edge_distance)/(blend_width)));\n"
" }\n"
" else\n"
" {\n"
" return vec4(0.0, 0.0, 0.0, 0.0);\n"
" }\n"
"#endif\n"
"}\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 scale = 1.0/numSamples;\n"
" vec4 total_color = vec4(0.0,0.0,0.0,0.0);\n"
"\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"
" #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"
" #endif\n"
"\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"
" vec4 c = distanceFieldColorSample(distanceFromEdge(pos), blend_width, blend_half_width);\n"
" total_color = total_color + c * c.a;\n"
" pos += delta_tx;\n"
" }\n"
" origin += delta_ty;\n"
" }\n"
"\n"
" total_color.rgb /= total_color.a;\n"
" total_color.a *= scale;\n"
"\n"
" return total_color;\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);\n"
"\n"
" float background_alpha = 1.0;\n"
"\n"
" for(float i=0.0; i<numSamples; ++i)\n"
" {\n"
" for(float j=0.0; j<numSamples; ++j)\n"
" {\n"
" float local_alpha = TEXTURE(glyphTexture, origin + vec2(i*delta_tc, j*delta_tc)).ALPHA;\n"
" outline_alpha = max(outline_alpha, local_alpha);\n"
" background_alpha = background_alpha * (1.0-local_alpha);\n"
" }\n"
" }\n"
"\n"
" #ifdef osg_TextureQueryLOD\n"
" float mipmapLevel = osg_TextureQueryLOD(glyphTexture, src_texCoord).x;\n"
" if (mipmapLevel<1.0)\n"
" {\n"
" outline_alpha = mix(1.0-background_alpha, outline_alpha, mipmapLevel/1.0);\n"
" }\n"
" #endif\n"
"\n"
" if (outline_alpha<alpha) outline_alpha = alpha;\n"
" if (outline_alpha>1.0) 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 = 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"
" vec4 color = mix(shadow_color, glyph_color, glyph_color.a);\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";

View File

@ -1,35 +0,0 @@
char text_greyscale_frag[] = "$OSG_GLSL_VERSION\n"
"$OSG_PRECISION_FLOAT\n"
"\n"
"#pragma import_defines( BACKDROP_COLOR, OUTLINE, ALPHA )\n"
"\n"
"#if __VERSION__>=130\n"
" #define TEXTURE texture\n"
" out vec4 osg_FragColor;\n"
"#else\n"
" #define TEXTURE texture2D\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 ALPHA\n"
" #if !defined(GL_ES) && __VERSION__>=130\n"
" #define ALPHA r\n"
" #else\n"
" #define ALPHA a\n"
" #endif\n"
"#endif\n"
"\n"
"void main(void)\n"
"{\n"
" float alpha = TEXTURE(glyphTexture, texCoord).ALPHA;\n"
"\n"
" if (alpha==0.0) discard;\n"
"\n"
" osg_FragColor = vec4(vertexColor.rgb, alpha);\n"
"}\n"
"\n";

View File

@ -1,257 +0,0 @@
char text_sdf_frag[] = "$OSG_GLSL_VERSION\n"
"\n"
"#pragma import_defines( BACKDROP_COLOR, SHADOW, OUTLINE, SIGNED_DISTNACE_FIELD, TEXTURE_DIMENSION, GLYPH_DIMENSION)\n"
"\n"
"#ifdef GL_ES\n"
" #extension GL_OES_standard_derivatives : enable\n"
" #ifndef GL_OES_standard_derivatives\n"
" #undef SIGNED_DISTNACE_FIELD\n"
" #endif\n"
"#endif\n"
"\n"
"#if !defined(GL_ES)\n"
" #if __VERSION__>=400\n"
" #define osg_TextureQueryLOD textureQueryLod\n"
" #else\n"
" #extension GL_ARB_texture_query_lod : enable\n"
" #ifdef GL_ARB_texture_query_lod\n"
" #define osg_TextureQueryLOD textureQueryLOD\n"
" #endif\n"
" #endif\n"
"#endif\n"
"\n"
"$OSG_PRECISION_FLOAT\n"
"\n"
"#if __VERSION__>=130\n"
" #define TEXTURE texture\n"
" #define TEXTURELOD textureLod\n"
" out vec4 osg_FragColor;\n"
"#else\n"
" #define TEXTURE texture2D\n"
" #define TEXTURELOD texture2DLod\n"
" #define osg_FragColor gl_FragColor\n"
"#endif\n"
"\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"
"\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_DISTNACE_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"
"vec4 distanceFieldColorSample(float edge_distance, float blend_width, float blend_half_width)\n"
"{\n"
"#ifdef OUTLINE\n"
" float outline_width = OUTLINE*0.5;\n"
" if (edge_distance>blend_half_width)\n"
" {\n"
" return vertexColor;\n"
" }\n"
" else if (edge_distance>-blend_half_width)\n"
" {\n"
" return mix(vertexColor, BACKDROP_COLOR, smoothstep(0.0, 1.0, (blend_half_width-edge_distance)/(blend_width)));\n"
" }\n"
" else if (edge_distance>(blend_half_width-outline_width))\n"
" {\n"
" return BACKDROP_COLOR;\n"
" }\n"
" else if (edge_distance>-(outline_width+blend_half_width))\n"
" {\n"
" return vec4(BACKDROP_COLOR.rgb, ((blend_half_width+outline_width+edge_distance)/blend_width));\n"
" }\n"
" else\n"
" {\n"
" return vec4(0.0, 0.0, 0.0, 0.0);\n"
" }\n"
"#else\n"
" if (edge_distance>blend_half_width)\n"
" {\n"
" return vertexColor;\n"
" }\n"
" else if (edge_distance>-blend_half_width)\n"
" {\n"
" return vec4(vertexColor.rgb, smoothstep(1.0, 0.0, (blend_half_width-edge_distance)/(blend_width)));\n"
" }\n"
" else\n"
" {\n"
" return vec4(0.0, 0.0, 0.0, 0.0);\n"
" }\n"
"#endif\n"
"}\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 scale = 1.0/numSamples;\n"
" vec4 total_color = vec4(0.0,0.0,0.0,0.0);\n"
"\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"
" #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"
" #endif\n"
"\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"
" vec4 c = distanceFieldColorSample(distanceFromEdge(pos), blend_width, blend_half_width);\n"
" total_color = total_color + c * c.a;\n"
" pos += delta_tx;\n"
" }\n"
" origin += delta_ty;\n"
" }\n"
"\n"
" total_color.rgb /= total_color.a;\n"
" total_color.a *= scale;\n"
"\n"
" return total_color;\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);\n"
"\n"
" float background_alpha = 1.0;\n"
"\n"
" for(float i=0.0; i<numSamples; ++i)\n"
" {\n"
" for(float j=0.0; j<numSamples; ++j)\n"
" {\n"
" float local_alpha = TEXTURE(glyphTexture, origin + vec2(i*delta_tc, j*delta_tc)).ALPHA;\n"
" outline_alpha = max(outline_alpha, local_alpha);\n"
" background_alpha = background_alpha * (1.0-local_alpha);\n"
" }\n"
" }\n"
"\n"
" #ifdef osg_TextureQueryLOD\n"
" float mipmapLevel = osg_TextureQueryLOD(glyphTexture, src_texCoord).x;\n"
" if (mipmapLevel<1.0)\n"
" {\n"
" outline_alpha = mix(1.0-background_alpha, outline_alpha, mipmapLevel/1.0);\n"
" }\n"
" #endif\n"
"\n"
" if (outline_alpha<alpha) outline_alpha = alpha;\n"
" if (outline_alpha>1.0) 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 = 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"
" vec4 color = mix(shadow_color, glyph_color, glyph_color.a);\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";