solstice

commit cda569edf64c3f5aa8ba48d9882359757ea05902
parent b4d0c653d6d4256757a88649f8e5961257cc92c5
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed,  4 Jan 2017 11:15:04 +0100

Basic version of the Solstice rendering functionnality

Diffstat:
M
src/solstice_draw.c
 | 
58
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 58 insertions(+), 0 deletions(-)
diff --git a/src/solstice_draw.c b/src/solstice_draw.c
@@ -15,8 +15,48 @@
 
 #include "solstice_c.h"
 
+#include <rsys/image.h>
 #include <solstice/ssol.h>
 
+#define SCREEN_GAMMA 2.2
+
+/*******************************************************************************
+ * Helper function
+ ******************************************************************************/
+/* Assume that the pixel format of the src is DOUBLE3 in gray scale while the
+ * pixel format of dst is UBYTE */
+static void
+tone_map(const double* src, unsigned char* dst,  const size_t count)
+{
+  size_t i;
+  ASSERT(src && dst && count);
+  FOR_EACH(i, 0, count) {
+    double val;
+    val = pow(src[i*3/*#channels*/], 1/SCREEN_GAMMA);/* Gamma correction */
+    val = CLAMP(val, 0, 1);
+    dst[i] =  (unsigned char)((val * 255) + 0.5/*round*/);
+  }
+}
+
+static void
+tone_map_image(const struct ssol_image* img, unsigned char* dst)
+{
+  struct ssol_image_layout layout;
+  size_t irow = 0;
+  void* mem;
+  ASSERT(img && dst);
+
+  SSOL(image_get_layout(img, &layout));
+  ASSERT(layout.pixel_format == SSOL_PIXEL_DOUBLE3);
+
+  SSOL(image_map(img, &mem));
+  FOR_EACH(irow, 0, layout.height) {
+    const void* src_row = ((char*)mem) + layout.offset + irow * layout.row_pitch;
+    unsigned char* dst_row = dst + irow * layout.width;
+    tone_map(src_row, dst_row, layout.width);
+  }
+}
+
 /*******************************************************************************
  * Local functions
  ******************************************************************************/
@@ -24,10 +64,17 @@ res_T
 solstice_draw(struct solstice* solstice)
 {
   struct ssol_image_layout layout;
+  unsigned char* ubytes = NULL;
   res_T res = RES_OK;
   ASSERT(solstice);
 
   SSOL(image_get_layout(solstice->framebuffer, &layout));
+  ubytes = MEM_ALLOC(solstice->allocator, layout.width*layout.height);
+  if(!ubytes) {
+    fprintf(stderr, "Could not allocate the 8-bits image buffer.\n");
+    res = RES_MEM_ERR;
+    goto error;
+  }
 
   res = ssol_draw(solstice->scene, solstice->camera, layout.width,
     layout.height, ssol_image_write, solstice->framebuffer);
@@ -36,8 +83,19 @@ solstice_draw(struct solstice* solstice)
     goto error;
   }
 
+  tone_map_image(solstice->framebuffer, ubytes);
+  res = image_ppm_write_stream(solstice->output, (int)layout.width,
+    (int)layout.height, 1, ubytes);
+  if(res != RES_OK) {
+    fprintf(stderr,
+      "Could not write the rendered image to the output stream.\n");
+    goto error;
+  }
+
 exit:
+  if(ubytes) MEM_RM(solstice->allocator, ubytes);
   return res;
 error:
   goto exit;
 }
+