diff options
| -rw-r--r-- | chickadee/graphics/path.scm | 72 |
1 files changed, 68 insertions, 4 deletions
diff --git a/chickadee/graphics/path.scm b/chickadee/graphics/path.scm index f97ca4a..f6bfcdb 100644 --- a/chickadee/graphics/path.scm +++ b/chickadee/graphics/path.scm @@ -1221,9 +1221,74 @@ ;;; Rendering ;;; +(define-vertex-shader stroke-vertex + ((in vec2 position) + (in vec2 tex) + (in float stroke-length) + (out vec2 frag-tex) + (out float frag-stroke-length) + (uniform mat4 mvp) + (uniform vec4 color)) + ;; Short-circuit because the fragments will just be discarded + ;; anyway. + (if (<= (-> color w) 0.0) + (outputs + (vertex:position (vec4 0.0 0.0 0.0 1.0))) + (outputs + (vertex:position (* mvp (vec4 (-> position x) (-> position y) 0.0 1.0))) + (frag-tex tex) + (frag-stroke-length stroke-length)))) + +(define-fragment-shader stroke-fragment + ((in vec2 frag-tex) + (in float frag-stroke-length) + (out vec4 frag-color) + (uniform vec4 color) + (uniform float feather) + (uniform int stroke-closed) + (uniform float stroke-width) + (uniform int stroke-cap) + (uniform float stroke-miter-limit)) + (if (<= (-> color w) 0.0) + (outputs) + (let* ((infinity (/ 1.0 0.0)) + (hw (/ stroke-width 2.0)) + (u (-> frag-tex x)) + (v (-> frag-tex y)) + (dx (if (< u 0.0) (abs u) (- u frag-stroke-length))) + (dy (abs v)) + ;; Signed distance function that applies end cap styles. + (d (if (or (< u 0.0) (> u frag-stroke-length)) + (case stroke-cap + ((0) ; none + infinity) + ((1) ; butt (hehe) + (max (- (+ dx hw) (* 2.0 feather)) dy)) + ((2) ; square + (max dx dy)) + ((3) ; round + (sqrt (+ (* dx dx) (* dy dy)))) + ((4) ; triangle out + (+ dx dy)) + ((5) ; triangle in + (max dy (- hw (+ feather dx) dy))) + (else ; unknown + 0.0)) + dy)) + (color* (if (<= d hw) + color + (vec4 (-> color x) + (-> color y) + (-> color z) + (* (-> color w) + (- 1.0 (/ (- d hw) feather))))))) + (if (<= (-> color w) 0.0) + (outputs) + (outputs + (frag-color color*)))))) + (define-graphics-variable stroke-shader - (load-shader (scope-datadir "shaders/path-stroke-vert.glsl") - (scope-datadir "shaders/path-stroke-frag.glsl"))) + (compile-shader stroke-vertex stroke-fragment)) (define-vertex-shader fill-vertex ((in vec2 position) @@ -1258,8 +1323,7 @@ 0.0 1.0))) (mix color end-color t))))) (if (<= (-> color w) 0.0) - (outputs - (frag-color (vec4 1.0 1.0 1.0 1.0))) + (outputs) (outputs (frag-color (case mode |