First pass of rendering engine rewrite.

The (chickadee graphics gpu) module now handles most of the low-level
OpenGL object creation/deletion/binding.  The (chickadee graphics
engine) module handles the with-graphics-state stuff via a render
context object.  There's lots of stuff that isn't great, but it's the
first step towards a graphics backend agnostic rendering layer.

6 files changed, 104 insertions, 12 deletions

diff --git a/examples/model.scm b/examples/model.scm
index 4fa42c7..35aceb5 100644
--- a/examples/model.scm
+++ b/examples/model.scm
@@ -26,7 +26,7 @@
   (reset-position))
 
 (define (draw alpha)
-  (with-projection projection
+  (with-graphics-state ((projection projection))
     (draw-model model
                 #:model-matrix model-matrix
                 #:view-matrix view-matrix
diff --git a/examples/path.scm b/examples/path.scm
index 44cabdb..ef9bf8f 100644
--- a/examples/path.scm
+++ b/examples/path.scm
@@ -4,7 +4,8 @@
              (chickadee graphics text)
              (chickadee math)
              (chickadee math vector)
-             (chickadee scripting))
+             (chickadee scripting)
+             (ice-9 format))
 
 (set! *random-state* (random-state-from-platform))
 
diff --git a/examples/sprite-batch.scm b/examples/sprite-batch.scm
index e62d1e4..cf79565 100644
--- a/examples/sprite-batch.scm
+++ b/examples/sprite-batch.scm
@@ -3,6 +3,7 @@
              (chickadee math rect)
              (chickadee math vector)
              (chickadee graphics color)
+             (chickadee graphics path)
              (chickadee graphics sprite)
              (chickadee graphics text)
              (chickadee graphics texture)
@@ -28,22 +29,28 @@
 (define matrix (make-identity-matrix4))
 
 (define (stats-message)
-  (format #f "sprites: ~d   fps: ~1,2f"
+  (format #f "sprites: ~d  fps: ~1,2f"
           num-sprites
           (/ 1.0 avg-frame-time)))
-
+(define stats-text-pos (vec2 8.0 462.0))
 (define stats-text (stats-message))
+(define stats-background
+  (with-style ((fill-color tango-light-plum))
+    (fill
+     (rounded-rectangle (vec2- stats-text-pos (vec2 4.0 4.0))
+                        212.0 18.0 #:radius 4.0))))
+(define stats-canvas (make-empty-canvas))
 
 (define (load)
   (set! *random-state* (random-state-from-platform))
   (set! texture (load-image "images/shot.png"))
   (set! batch (make-sprite-batch texture #:capacity num-sprites))
+  (set-canvas-painter! stats-canvas stats-background)
   (script
    (forever
     (sleep 60)
     (set! stats-text (pk 'stats (stats-message))))))
 
-(define stats-text-pos (vec2 4.0 464.0))
 (define (draw alpha)
   (sprite-batch-clear! batch)
   (for-each (match-lambda
@@ -53,7 +60,8 @@
               (sprite-batch-add* batch r matrix)))
             sprites)
   (draw-sprite-batch batch)
-  (draw-text stats-text stats-text-pos #:color black)
+  (draw-canvas stats-canvas)
+  (draw-text stats-text stats-text-pos #:color tango-aluminium-6)
   (let ((current-time (elapsed-time)))
     (set! avg-frame-time
           (+ (* (- current-time start-time) 0.1)
diff --git a/examples/sprite.scm b/examples/sprite.scm
index 24b7a24..753be4d 100644
--- a/examples/sprite.scm
+++ b/examples/sprite.scm
@@ -8,10 +8,11 @@
 (define sprite #f)
 
 (define (load)
-  (pk (blending-factor-src 2))
   (set! sprite (load-image "images/chickadee.png")))
 
 (define (draw alpha)
-  (draw-sprite sprite (vec2 256.0 176.0)))
+  (draw-sprite sprite (vec2 256.0 176.0))
+  ;;(abort-game)
+  )
 
 (run-game #:load load #:draw draw)
diff --git a/examples/text.scm b/examples/text.scm
index be79edc..81e4021 100644
--- a/examples/text.scm
+++ b/examples/text.scm
@@ -7,7 +7,7 @@
 (define avg-frame-time 16.0)
 (define stats-text "")
 (define stats-position (vec2 4.0 704.0))
-(define position (vec2 140.0 0.0))
+(define position (vec2 140.0 240.0))
 (define text "The quick brown fox jumps over the lazy dog.\nFive hexing wizard bots jump quickly.")
 
 (define (stats-message)
@@ -40,6 +40,4 @@
           #:key-press key-press
           #:load load
           #:update update
-          #:window-title "text rendering"
-          #:window-width 1280
-          #:window-height 720)
+          #:window-title "text rendering")
diff --git a/examples/triangle.scm b/examples/triangle.scm
new file mode 100644
index 0000000..2debc85
--- /dev/null
+++ b/examples/triangle.scm
@@ -0,0 +1,84 @@
+(use-modules (chickadee)
+             (chickadee math vector)
+             (chickadee graphics buffer)
+             (chickadee graphics engine)
+             (chickadee graphics shader))
+
+(use-modules (gl enums))
+
+(define vertex-array #f)
+(define shader #f)
+
+(define (load)
+  (define verts
+    (make-buffer #f32(0.0 0.0
+                          640.0 0.0
+                          320.0 480.0)))
+  (define colors
+    (make-buffer #f32(1.0 0.0 0.0 1.0
+                          0.0 1.0 0.0 1.0
+                          0.0 0.0 1.0 1.0)))
+  ;; This isn't necessary for a single triangle, but we're doing it
+  ;; anyway just to exercise that code.
+  (define indices (make-buffer #u32(0 1 2) #:target 'index))
+  (set! vertex-array
+        (make-vertex-array
+         #:indices (make-vertex-attribute
+                    #:buffer indices
+                    #:type 'scalar
+                    #:component-type 'unsigned-int)
+         #:attributes `((0 . ,(make-vertex-attribute
+                               #:buffer verts
+                               #:type 'vec2
+                               #:component-type 'float))
+                        (1 . ,(make-vertex-attribute
+                               #:buffer colors
+                               #:type 'color
+                               #:component-type 'float)))))
+  (set! shader (strings->shader
+                "
+#ifdef GLSL330
+layout (location = 0) in vec2 position;
+layout (location = 1) in vec4 color;
+#elif defined(GLSL130)
+in vec2 position;
+in vec4 color;
+#elif defined(GLSL120)
+attribute vec2 position;
+attribute vec4 color;
+#endif
+#ifdef GLSL120
+varying vec4 fragColor;
+#else
+out vec4 fragColor;
+#endif
+uniform mat4 mvp;
+
+void main(void) {
+    fragColor = color;
+    gl_Position = mvp * vec4(position, 0.0, 1.0);
+}
+"
+                "
+#ifdef GLSL120
+varying vec4 fragColor;
+#else
+in vec4 fragColor;
+ #endif
+#ifdef GLSL330
+out vec4 outFragColor;
+#endif
+
+void main (void) {
+#ifdef GLSL330
+    outFragColor = fragColor;
+#else
+    gl_FragColor = fragColor;
+#endif
+}
+")))
+
+(define (draw alpha)
+  (shader-apply shader vertex-array #:mvp (current-projection)))
+
+(run-game #:load load #:draw draw)