Fix beziers on GPU.

We can now render an SVG correctly(ish)! Woah!

diff --git a/src/bezier.cpp b/src/bezier.cpp
index c71d0a9..f0e1f4d 100644 (file)
--- a/src/bezier.cpp
+++ b/src/bezier.cpp
@@ -34,7 +34,7 @@ int Factorial(int n)
  */
 int BinomialCoeff(int n, int k)
 {
-       return Factorial(n) / Factorial(k) / Factorial(n-k);
+       return Factorial(n) / (Factorial(k) * Factorial(n-k));
 }
 
 /**

diff --git a/src/objectrenderer.cpp b/src/objectrenderer.cpp
index 76955a6..8b3b7e4 100644 (file)
--- a/src/objectrenderer.cpp
+++ b/src/objectrenderer.cpp
@@ -281,8 +281,8 @@ void BezierRenderer::PrepareBezierGPUBuffer(const Objects& objects)
        {
                GPUBezierCoeffs coeffs = {
                        Float(bez->x0), Float(bez->y0),
-                       Float(bez->x1 - bez->x0), Float(bez->y1 - bez->y0),
-                       Float(bez->x2 - bez->x0), Float(bez->y2 - bez->y0)
+                       Float(bez->x1), Float(bez->y1),
+                       Float(bez->x2), Float(bez->y2)
                        };
                builder.Add(coeffs);
        }

diff --git a/src/shaders/bezier_texbuf_geom.glsl b/src/shaders/bezier_texbuf_geom.glsl
index 56dddbe..bb9a219 100644 (file)
--- a/src/shaders/bezier_texbuf_geom.glsl
+++ b/src/shaders/bezier_texbuf_geom.glsl
@@ -19,9 +19,9 @@ void main()
 {
        int bezierid = texelFetch(bezier_id_buffer_texture, objectid[0]).r;
        vec2 boundssize = gl_in[1].gl_Position.xy - gl_in[0].gl_Position.xy;
-       vec2 coeff0 = texelFetch(bezier_buffer_texture, bezierid*3).rg + gl_in[0].gl_Position.xy ;
-       vec2 coeff1 = texelFetch(bezier_buffer_texture, bezierid*3+1).rg * boundssize + gl_in[0].gl_Position.xy;
-       vec2 coeff2 = texelFetch(bezier_buffer_texture, bezierid*3+2).rg * boundssize + gl_in[0].gl_Position.xy;
+       vec2 coeff0 = texelFetch(bezier_buffer_texture, bezierid*3).rg;
+       vec2 coeff1 = texelFetch(bezier_buffer_texture, bezierid*3+1).rg;
+       vec2 coeff2 = texelFetch(bezier_buffer_texture, bezierid*3+2).rg;
        vec2 boundspxsize = pixsize[0];
        int blen = clamp(int(abs(boundspxsize.x)),2,100);
        float invblen = 1.0f/float(blen);
@@ -32,7 +32,7 @@ void main()
                float bernstein0 = t*t;
                float bernstein1 = 2*t*oneminust;
                float bernstein2 = oneminust*oneminust;
-               gl_Position = vec4(coeff0*bernstein0 + coeff1*bernstein1 + coeff2*bernstein2, 0.0, 1.0);
+               gl_Position = vec4((coeff0*bernstein0 + coeff1*bernstein1 + coeff2*bernstein2) * boundssize + gl_in[0].gl_Position.xy, 0.0, 1.0);
                EmitVertex();
                
        }