graphics: Add color mask support.

3 files changed, 64 insertions, 7 deletions

diff --git a/chickadee/graphics.scm b/chickadee/graphics.scm
index bfa1139..10ff18f 100644
--- a/chickadee/graphics.scm
+++ b/chickadee/graphics.scm
@@ -25,6 +25,7 @@
   #:use-module (chickadee math matrix)
   #:use-module (chickadee graphics gpu)
   #:use-module (chickadee graphics blend)
+  #:use-module (chickadee graphics color)
   #:use-module (chickadee graphics framebuffer)
   #:use-module (chickadee graphics shader)
   #:use-module (chickadee graphics texture)
@@ -39,6 +40,7 @@
             current-texture
             current-projection
             current-multisample
+            current-color-mask
             with-viewport
             with-framebuffer
             with-blend-mode
@@ -47,6 +49,7 @@
             with-texture
             with-projection
             with-multisample
+            with-color-mask
             clear-screen
             gpu-apply
             gpu-apply*
@@ -55,7 +58,8 @@
 
 (define-record-type <render-context>
   (make-render-context viewport framebuffer blend-mode depth-test
-                       stencil-test projection multisample? textures)
+                       stencil-test projection multisample? color-mask
+                       textures)
   render-context?
   (viewport render-context-viewport set-render-context-viewport!)
   (framebuffer render-context-framebuffer set-render-context-framebuffer!)
@@ -64,6 +68,7 @@
   (stencil-test render-context-stencil-test set-render-context-stencil-test!)
   (projection render-context-projection set-render-context-projection!)
   (multisample? render-context-multisample? set-render-context-multisample!)
+  (color-mask render-context-color-mask set-render-context-color-mask!)
   (textures render-context-textures))
 
 (define render-context
@@ -74,6 +79,7 @@
                        #f
                        (make-identity-matrix4)
                        #f
+                       default-color-mask
                        (make-vector 32 null-texture)))
 
 (define (current-viewport)
@@ -100,6 +106,9 @@
 (define (current-multisample)
   (render-context-multisample? render-context))
 
+(define (current-color-mask)
+  (render-context-color-mask render-context))
+
 (define-syntax-rule (with (getter setter value) body ...)
   (let ((prev (getter render-context)))
     (setter render-context value)
@@ -154,6 +163,10 @@
   (with (render-context-multisample? set-render-context-multisample! multisample?)
         body ...))
 
+(define-syntax-rule (with-color-mask color-mask body ...)
+  (with (render-context-color-mask set-render-context-color-mask! color-mask)
+        body ...))
+
 (define (keyword->string kw)
   (symbol->string (keyword->symbol kw)))
 
@@ -179,6 +192,7 @@
     (set-gpu-depth-test! gpu (current-depth-test))
     (set-gpu-stencil-test! gpu (current-stencil-test))
     (set-gpu-multisample! gpu (current-multisample))
+    (set-gpu-color-mask! gpu (current-color-mask))
     (set-gpu-shader! gpu shader)
     (let loop ((i 0))
       (when (< i 32)
diff --git a/chickadee/graphics/color.scm b/chickadee/graphics/color.scm
index 497ecd3..2e1bf43 100644
--- a/chickadee/graphics/color.scm
+++ b/chickadee/graphics/color.scm
@@ -22,10 +22,11 @@
 ;;; Code:
 
 (define-module (chickadee graphics color)
+  #:use-module (chickadee graphics gl)
+  #:use-module (chickadee math)
   #:use-module (ice-9 match)
   #:use-module (srfi srfi-9)
   #:use-module (srfi srfi-1)
-  #:use-module (chickadee math)
   #:export (make-color
             color?
             color-r color-g color-b color-a
@@ -41,7 +42,17 @@
             tango-light-plum tango-plum tango-dark-plum
             tango-light-scarlet-red tango-scarlet-red tango-dark-scarlet-red
             tango-aluminium-1 tango-aluminium-2 tango-aluminium-3
-            tango-aluminium-4 tango-aluminium-5 tango-aluminium-6))
+            tango-aluminium-4 tango-aluminium-5 tango-aluminium-6
+
+            make-color-mask
+            default-color-mask
+            null-color-mask
+            color-mask?
+            color-mask-red?
+            color-mask-green?
+            color-mask-blue?
+            color-mask-alpha?
+            apply-color-mask))
 
 (define-record-type <color>
   (wrap-color bv)
@@ -171,6 +182,7 @@ a color object."
   (color+ (color* start (- 1.0 alpha))
           (color* end alpha)))
 
+
 ;;;
 ;;; Pre-defined Colors
 ;;;
@@ -215,3 +227,25 @@ a color object."
 (define tango-aluminium-4 (rgb #x888a85))
 (define tango-aluminium-5 (rgb #x555753))
 (define tango-aluminium-6 (rgb #x2e3436))
+
+
+;;;
+;;; Color Masks
+;;;
+
+(define-record-type <color-mask>
+  (make-color-mask red? green? blue? alpha?)
+  color-mask?
+  (red? color-mask-red?)
+  (green? color-mask-green?)
+  (blue? color-mask-blue?)
+  (alpha? color-mask-alpha?))
+
+(define default-color-mask (make-color-mask #t #t #t #t))
+(define null-color-mask (make-color-mask #f #f #f #f))
+
+(define (apply-color-mask mask)
+  (gl-color-mask (color-mask-red? mask)
+                 (color-mask-green? mask)
+                 (color-mask-blue? mask)
+                 (color-mask-alpha? mask)))
diff --git a/chickadee/graphics/gpu.scm b/chickadee/graphics/gpu.scm
index 7a70d7e..16f5554 100644
--- a/chickadee/graphics/gpu.scm
+++ b/chickadee/graphics/gpu.scm
@@ -47,6 +47,7 @@
             gpu-vertex-array
             gpu-viewport
             gpu-multisample
+            gpu-color-mask
             set-gpu-blend-mode!
             set-gpu-depth-test!
             set-gpu-stencil-test!
@@ -56,7 +57,8 @@
             set-gpu-vertex-buffer!
             set-gpu-vertex-array!
             set-gpu-viewport!
-            set-gpu-multisample!))
+            set-gpu-multisample!
+            set-gpu-color-mask!))
 
 
 ;;;
@@ -114,7 +116,8 @@ from the GPU's memory."
              vertex-buffer
              vertex-array
              viewport
-             multisample)
+             multisample
+             color-mask)
   gpu?
   (gl-context gpu-gl-context)
   (gl-version gpu-gl-version)
@@ -129,7 +132,8 @@ from the GPU's memory."
   (vertex-buffer %gpu-vertex-buffer)
   (vertex-array %gpu-vertex-array)
   (viewport %gpu-viewport)
-  (multisample %gpu-multisample))
+  (multisample %gpu-multisample)
+  (color-mask %gpu-color-mask))
 
 (define current-gpu (make-parameter #f))
 
@@ -157,6 +161,7 @@ from the GPU's memory."
         (shader-module (resolve-interface '(chickadee graphics shader)))
         (texture-module (resolve-interface '(chickadee graphics texture)))
         (viewport-module (resolve-interface '(chickadee graphics viewport)))
+        (color-module (resolve-interface '(chickadee graphics color)))
         (gl-version (extract-version (string-name version)))
         (glsl-version (extract-version (version-2-0 shading-language-version))))
     ;; Create state for 32 texture units.
@@ -187,7 +192,9 @@ from the GPU's memory."
                                (module-ref buffer-module 'null-vertex-array))
                (make-gpu-state (module-ref viewport-module 'apply-viewport)
                                (module-ref viewport-module 'null-viewport))
-               (make-gpu-state apply-multisample #f))))
+               (make-gpu-state apply-multisample #f)
+               (make-gpu-state (module-ref color-module 'apply-color-mask)
+                               (module-ref color-module 'default-color-mask)))))
 
 (define-syntax-rule (define-gpu-getter name ref)
   (define (name gpu)
@@ -202,6 +209,7 @@ from the GPU's memory."
 (define-gpu-getter gpu-vertex-array %gpu-vertex-array)
 (define-gpu-getter gpu-viewport %gpu-viewport)
 (define-gpu-getter gpu-multisample %gpu-multisample)
+(define-gpu-getter gpu-color-mask %gpu-color-mask)
 
 (define-syntax-rule (define-gpu-setter name ref)
   (define (name gpu x)
@@ -216,6 +224,7 @@ from the GPU's memory."
 (define-gpu-setter set-gpu-vertex-array! %gpu-vertex-array)
 (define-gpu-setter set-gpu-viewport! %gpu-viewport)
 (define-gpu-setter set-gpu-multisample! %gpu-multisample)
+(define-gpu-setter set-gpu-color-mask! %gpu-color-mask)
 
 (define (gpu-texture gpu texture-unit)
   (gpu-state-ref (vector-ref (gpu-textures gpu) texture-unit)))