public BasicFillShader(CanvasToShaderSharedResource canvasShareResource)
: base(canvasShareResource)
{
//----------------
//vertex shader source
string vs = @"
attribute vec2 a_position;
uniform mat4 u_mvpMatrix;
uniform vec4 u_solidColor;
varying vec4 v_color;
void main()
{
gl_Position = u_mvpMatrix* vec4(a_position[0],a_position[1],0,1);
v_color= u_solidColor;
}
";
//fragment source
string fs = @"
precision mediump float;
varying vec4 v_color;
void main()
{
gl_FragColor = v_color;
}
";
if (!shaderProgram.Build(vs, fs))
{
throw new NotSupportedException();
}
a_position = shaderProgram.GetAttrV2f("a_position");
u_matrix = shaderProgram.GetUniformMat4("u_mvpMatrix");
u_solidColor = shaderProgram.GetUniform4("u_solidColor");
}
protected override void OnProgramBuilt()
{
_u_color = shaderProgram.GetUniform4("u_color");
_u_buffer = shaderProgram.GetUniform1("u_buffer");
_u_gamma = shaderProgram.GetUniform1("u_gamma");
}
public InvertAlphaLineSmoothShader(CanvasToShaderSharedResource canvasShareResource)
: base(canvasShareResource)
{
//-------------------------------------------------------------------------------
string vs = @"
attribute vec4 a_position;
uniform mat4 u_mvpMatrix;
uniform vec4 u_solidColor;
uniform float u_linewidth;
varying vec4 v_color;
varying float v_distance;
varying float p0;
void main()
{
float rad = a_position[3];
v_distance= a_position[2];
float n_x = sin(rad);
float n_y = cos(rad);
vec4 delta;
if(v_distance <1.0){
delta = vec4(-n_x * u_linewidth,n_y * u_linewidth,0,0);
}else{
delta = vec4(n_x * u_linewidth,-n_y * u_linewidth,0,0);
}
if(u_linewidth <= 0.5){
p0 = 0.5;
}else if(u_linewidth <=1.0){
p0 = 0.45;
}else if(u_linewidth>1.0 && u_linewidth<3.0){
p0 = 0.25;
}else{
p0= 0.1;
}
vec4 pos = vec4(a_position[0],a_position[1],0,1) + delta;
gl_Position = u_mvpMatrix* pos;
v_color= u_solidColor;
}
";
//fragment source
//this is invert fragment shader ***
//so we
string fs = @"
precision mediump float;
varying vec4 v_color;
varying float v_distance;
varying float p0;
void main()
{
float d0= v_distance;
float p1= 1.0-p0;
float factor= 1.0 /p0;
if(d0 < p0){
gl_FragColor = vec4(v_color[0],v_color[1],v_color[2], 1.0 -(v_color[3] *(d0 * factor)));
}else if(d0> p1){
gl_FragColor= vec4(v_color[0],v_color[1],v_color[2],1.0-(v_color[3] *((1.0-d0)* factor)));
}
else{
gl_FragColor = vec4(0,0,0,0);
}
}
";
//---------------------
if (!shaderProgram.Build(vs, fs))
{
return;
}
//-----------------------
a_position = shaderProgram.GetAttrV4f("a_position");
u_matrix = shaderProgram.GetUniformMat4("u_mvpMatrix");
u_solidColor = shaderProgram.GetUniform4("u_solidColor");
u_linewidth = shaderProgram.GetUniform1("u_linewidth");
_strokeColor = Drawing.Color.Black;
}
protected override void OnProgramBuilt()
{
_bgColor = shaderProgram.GetUniform4("bgColor");
_fgColor = shaderProgram.GetUniform4("fgColor");
}
internal void AssignStrokeColorToVar(OpenTK.Graphics.ES20.ShaderUniformVar4 color)
{
color.SetValue(_stroke_r, _stroke_g, _stroke_b, _stroke_a);
}