public SimpleCanvas(int view_width, int view_height)
{
FillColor = Color.Black;
StrokeColor = Color.Black;
//dimension
_view_width = view_width;
_view_height = view_height;
_max = Math.Max(view_width, view_height);
//------------
//matrix
////square viewport
_orthoView = MyMat4.ortho(0, _max, 0, _max, 0, 1);
_flipVerticalView = MyMat4.scale(1, -1) * MyMat4.translate(new OpenTK.Vector3(0, -_max, 0));
_orthoAndFlip = _orthoView * _flipVerticalView;
//-----------------------------------------------------------------------
//shader
_shaderRes = new CanvasToShaderSharedResource();
_shaderRes.OrthoView = _orthoView;
//
_fillShader = new GlyphFillShader(_shaderRes);
//------------
//tools
Tesselate.Tesselator tt = new Tesselate.Tesselator();
_tessTool = new TessTool(tt);
_curveFlattener = new SimpleCurveFlattener();
ClearColor = Color.White;
//--------
//set blend mode
GL.Enable(EnableCap.Blend);
GL.BlendFunc(BlendingFactorSrc.SrcAlpha, BlendingFactorDest.OneMinusSrcAlpha);
}
public GlyphFillShader(CanvasToShaderSharedResource canvasShareResource)
: base(canvasShareResource)
{
//----------------
//vertex shader source
string vs = @"
attribute vec2 a_position;
uniform mat4 u_mvpMatrix;
uniform vec4 u_solidColor;
uniform vec2 u_2d_offset;
varying vec4 v_color;
void main()
{
gl_Position = u_mvpMatrix* vec4(a_position[0] +u_2d_offset[0],a_position[1]+ u_2d_offset[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");
u_2d_offset = shaderProgram.GetUniform2("u_2d_offset");
}
public ShaderBase(CanvasToShaderSharedResource canvasShareResource)
{
_canvasShareResource = canvasShareResource;
}
