1 files changed, 47 insertions, 0 deletions
diff --git a/libglitter_create_render_context.c b/libglitter_create_render_context.c
new file mode 100644
index 0000000..53b0705
--- /dev/null
+++ b/libglitter_create_render_context.c
@@ -0,0 +1,47 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+LIBGLITTER_RENDER_CONTEXT *
+libglitter_create_render_context(size_t noutputs, size_t rowsize, size_t widthmul, size_t heightmul,
+                                 const uint8_t *cellmap, const uint8_t *ncellvalues)
+{
+	struct libglitter_render_context *this;
+	size_t i;
+
+	this = calloc(1, sizeof(*this));
+	if (!this)
+		return NULL;
+
+	this->cellmap = cellmap;
+	this->ncellvalues = ncellvalues;
+	this->noutputs = noutputs;
+	this->widthmul = widthmul;
+	this->heightmul = heightmul;
+	
+	this->cellweights_double = calloc(noutputs, sizeof(*this->cellweights_double));
+	if (!this->cellweights_double)
+		goto fail;
+	this->cellweights_float = calloc(noutputs, sizeof(*this->cellweights_float));
+	if (!this->cellweights_float)
+		goto fail;
+
+	this->render_method =
+		(noutputs == 3 && widthmul == 3 && heightmul == 1) ? RENDER_METHOD_VSTRIPS :
+		(noutputs == 3 && widthmul == 1 && heightmul == 3) ? RENDER_METHOD_HSTRIPS :
+		(noutputs == 3 && ncellvalues[0] <= 2 && ncellvalues[1] <= 2 && ncellvalues[2] <= 2) ? RENDER_METHOD_SIMPLE :
+		RENDER_METHOD_GENERIC;
+
+	for (i = 0; i < noutputs; i++) {
+		this->cellweights_double[i] = 1 / (double)ncellvalues[i];
+		this->cellweights_float[i] = 1 / (float)ncellvalues[i];
+	}
+
+	libglitter_update_render_context(this, rowsize);
+
+	return this;
+
+fail:
+	libglitter_free_render_context(this);
+	return NULL;
+}