diff options
| -rw-r--r-- | chickadee/render/buffer.scm | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/chickadee/render/buffer.scm b/chickadee/render/buffer.scm index 686197c..83a2925 100644 --- a/chickadee/render/buffer.scm +++ b/chickadee/render/buffer.scm @@ -66,6 +66,7 @@ typed-buffer-min typed-buffer-sparse typed-buffer-data + typed-buffer-divisor map-typed-buffer! unmap-typed-buffer! with-mapped-typed-buffer @@ -221,7 +222,7 @@ vertex buffer data back to the GPU." (define-record-type <typed-buffer> (%make-typed-buffer name buffer offset component-type - normalized? length type max min sparse) + normalized? length type max min sparse divisor) typed-buffer? (name typed-buffer-name) (buffer typed-buffer->buffer) @@ -232,7 +233,8 @@ vertex buffer data back to the GPU." (type typed-buffer-type) (max typed-buffer-max) (min typed-buffer-min) - (sparse typed-buffer-sparse)) + (sparse typed-buffer-sparse) + (divisor typed-buffer-divisor)) ; for instanced rendering (define (typed-buffer-stride typed-buffer) (or (buffer-stride (typed-buffer->buffer typed-buffer)) @@ -260,9 +262,10 @@ vertex buffer data back to the GPU." component-type)) max min - sparse) + sparse + divisor) (%make-typed-buffer name buffer offset component-type - normalized? length type max min sparse)) + normalized? length type max min sparse divisor)) (define (type-size type) (match type @@ -285,11 +288,14 @@ vertex buffer data back to the GPU." (define* (make-streaming-typed-buffer type component-type length #:key (name "anonymous") (target 'vertex) - data) + data + divisor) "Return a new typed buffer to hold LENGTH elements of TYPE whose components are comprised of COMPONENT-TYPE values. The underlying untyped buffer is configured for GPU streaming. Optonally, a NAME can -be specified for the buffer." +be specified for the buffer. If the buffer will be used for instanced +rendering, the DIVISOR argument must be used to specify the rate at +which attributes advance when rendering multiple instances." (let* ((buffer-length (* length (type-size type) (component-type-size component-type))) (buffer (if data @@ -305,7 +311,8 @@ be specified for the buffer." #:buffer buffer #:type type #:component-type component-type - #:length length))) + #:length length + #:divisor divisor))) (define (display-typed-buffer typed-buffer port) (format port "#<typed-buffer name: ~s buffer: ~a type: ~s component-type: ~s length: ~d offset: ~d>" @@ -353,7 +360,10 @@ be specified for the buffer." (typed-buffer-type-gl typed-buffer) (typed-buffer-normalized? typed-buffer) (typed-buffer-stride typed-buffer) - (make-pointer (typed-buffer-offset typed-buffer))))) + (make-pointer (typed-buffer-offset typed-buffer))) + (let ((divisor (typed-buffer-divisor typed-buffer))) + (when divisor + (gl-vertex-attrib-divisor attribute-index divisor))))) ;; TODO: Handle 4-byte alignment rule for the types that need it. (define (typed-buffer->vector typed-buffer) |