Port particle shader to Seagull.

1 files changed, 120 insertions, 79 deletions

diff --git a/chickadee/graphics/particles.scm b/chickadee/graphics/particles.scm
index d8bd1b2..6801c39 100644
--- a/chickadee/graphics/particles.scm
+++ b/chickadee/graphics/particles.scm
@@ -29,6 +29,7 @@
   #:use-module (chickadee graphics color)
   #:use-module (chickadee graphics engine)
   #:use-module (chickadee graphics shader)
+  #:use-module (chickadee graphics seagull)
   #:use-module (chickadee graphics texture)
   #:export (make-particle-emitter
             particle-emitter?
@@ -87,82 +88,121 @@ indefinitely."
   particle-vertex-set!
   particle-vertex-append!
   (position vec2)
+  (life int)
   (velocity vec2)
-  (acceleration vec2)
-  (life int))
+  (acceleration vec2))
+
+(define-vertex-shader particles-vertex
+  ((in vec2 position)
+   (in vec2 tex)
+   (in vec2 offset)
+   (in float life)
+   (out vec2 frag-tex)
+   (out float frag-t)
+   (uniform mat4 mvp)
+   (uniform int lifetime)
+   (uniform int animation-rows)
+   (uniform int animation-columns))
+  (let* ((p (+ position offset))
+         (t (/ life lifetime))
+         (num-tiles (* animation-rows animation-columns))
+         (tile (float->int (* num-tiles (- 1.0 t))))
+         (tx (/ (mod tile animation-columns)
+                animation-columns))
+         (ty (/ (int->float (/ tile animation-columns))
+                animation-columns))
+         (tw (/ 1.0 animation-columns))
+         (th (/ 1.0 animation-rows)))
+    (outputs
+     (vertex:position (* mvp (vec4 (-> p x) (-> p y) 0.0 1.0)))
+     (frag-tex (+ (vec2 tx ty) (* tex (vec2 tw th))))
+     (frag-t t))))
+
+(define-fragment-shader particles-fragment
+  ((in vec2 frag-tex)
+   (in float frag-t)
+   (out vec4 frag-color)
+   (uniform sampler-2d color-texture)
+   (uniform vec4 start-color)
+   (uniform vec4 end-color))
+  (outputs
+   (frag-color (* (mix end-color start-color frag-t)
+                  (texture-2d color-texture frag-tex)))))
 
 (define-graphics-variable particles-shader
-  (strings->shader
-   "
-#ifdef GLSL330
-layout (location = 0) in vec2 position;
-layout (location = 1) in vec2 tex;
-layout (location = 2) in vec2 offset;
-layout (location = 3) in vec2 velocity;
-layout (location = 4) in vec2 acceleration;
-layout (location = 5) in float life;
-#elif defined(GLSL130)
-in vec2 position;
-in vec2 tex;
-in vec2 offset;
-in vec2 velocity;
-in vec2 acceleration;
-in float life;
-#elif defined(GLSL120)
-attribute vec2 position;
-attribute vec2 tex;
-attribute vec2 offset;
-attribute vec2 velocity;
-attribute vec2 acceleration;
-attribute float life;
-#endif
-#ifdef GLSL120
-varying vec2 fragTex;
-varying float t;
-#else
-out vec2 fragTex;
-out float t;
-#endif
-uniform mat4 mvp;
-uniform int lifetime;
-uniform int animationRows;
-uniform int animationColumns;
-
-void main(void) {
-    t = life / lifetime;
-    int numTiles = animationRows * animationColumns;
-    int tile = int(numTiles * (1.0 - t));
-    float tx = float(mod(tile, animationColumns)) / animationColumns;
-    float ty = float(tile / animationColumns) / animationRows;
-    float tw = 1.0 / animationColumns;
-    float th = 1.0 / animationRows;
-    fragTex = vec2(tx, ty) + tex * vec2(tw, th);
-    gl_Position = mvp * vec4(position.xy + offset, 0.0, 1.0);
-}
-"
-   "
-#ifdef GLSL120
-varying vec2 fragTex;
-varying float t;
-#else
-in vec2 fragTex;
-in float t;
-#endif
-#ifdef GLSL330
-out vec4 fragColor;
-#endif
-uniform sampler2D color_texture;
-uniform vec4 startColor;
-uniform vec4 endColor;
-
-void main (void) {
-#ifdef GLSL330
-    fragColor = mix(endColor, startColor, t) * texture(color_texture, fragTex);
-#else
-    gl_FragColor = mix(endColor, startColor, t) * texture2D(color_texture, fragTex);
-#endif
-}
-"))
+  (compile-shader particles-vertex particles-fragment)
+;;   (strings->shader
+;;    "
+;; #ifdef GLSL330
+;; layout (location = 0) in vec2 position;
+;; layout (location = 1) in vec2 tex;
+;; layout (location = 2) in vec2 offset;
+;; layout (location = 3) in vec2 velocity;
+;; layout (location = 4) in vec2 acceleration;
+;; layout (location = 5) in float life;
+;; #elif defined(GLSL130)
+;; in vec2 position;
+;; in vec2 tex;
+;; in vec2 offset;
+;; in vec2 velocity;
+;; in vec2 acceleration;
+;; in float life;
+;; #elif defined(GLSL120)
+;; attribute vec2 position;
+;; attribute vec2 tex;
+;; attribute vec2 offset;
+;; attribute vec2 velocity;
+;; attribute vec2 acceleration;
+;; attribute float life;
+;; #endif
+;; #ifdef GLSL120
+;; varying vec2 fragTex;
+;; varying float t;
+;; #else
+;; out vec2 fragTex;
+;; out float t;
+;; #endif
+;; uniform mat4 mvp;
+;; uniform int lifetime;
+;; uniform int animationRows;
+;; uniform int animationColumns;
+
+;; void main(void) {
+;;     t = life / lifetime;
+;;     int numTiles = animationRows * animationColumns;
+;;     int tile = int(numTiles * (1.0 - t));
+;;     float tx = float(mod(tile, animationColumns)) / animationColumns;
+;;     float ty = float(tile / animationColumns) / animationRows;
+;;     float tw = 1.0 / animationColumns;
+;;     float th = 1.0 / animationRows;
+;;     fragTex = vec2(tx, ty) + tex * vec2(tw, th);
+;;     gl_Position = mvp * vec4(position.xy + offset, 0.0, 1.0);
+;; }
+;; "
+;;    "
+;; #ifdef GLSL120
+;; varying vec2 fragTex;
+;; varying float t;
+;; #else
+;; in vec2 fragTex;
+;; in float t;
+;; #endif
+;; #ifdef GLSL330
+;; out vec4 fragColor;
+;; #endif
+;; uniform sampler2D color_texture;
+;; uniform vec4 startColor;
+;; uniform vec4 endColor;
+
+;; void main (void) {
+;; #ifdef GLSL330
+;;     fragColor = mix(endColor, startColor, t) * texture(color_texture, fragTex);
+;; #else
+;;     gl_FragColor = mix(endColor, startColor, t) * texture2D(color_texture, fragTex);
+;; #endif
+;; }
+;; ")
+  )
 
 (define-graphics-variable mvp-matrix (make-null-matrix4))
 
@@ -317,12 +357,13 @@ default.
          (float-set! bytevector-ieee-single-native-set!)
          (int-ref bytevector-s32-native-ref)
          (int-set! bytevector-s32-native-set!)
+         (x-offset 0)
          (y-offset 4)
-         (dx-offset 8)
-         (dy-offset 12)
-         (ddx-offset 16)
-         (ddy-offset 20)
-         (life-offset 24))
+         (life-offset 8)
+         (dx-offset 12)
+         (dy-offset 16)
+         (ddx-offset 20)
+         (ddy-offset 24))
     (let* ((bv (particles-bv particles))
            (stride (geometry-type-stride <particle-vertex>))
            (capacity (particles-capacity particles)))
@@ -336,7 +377,7 @@ default.
                   (let ((new-size (- size 1)))
                     (bytevector-copy! bv (* new-size stride) bv offset stride)
                     (loop i new-size))
-                  (let ((x (float-ref bv offset))
+                  (let ((x (float-ref bv (+ offset x-offset)))
                         (y (float-ref bv (+ offset y-offset)))
                         (dx (float-ref bv (+ offset dx-offset)))
                         (dy (float-ref bv (+ offset dy-offset)))