[Bf-blender-cvs] [f276b08714d] greasepencil-object: Convert colors to linear for OpenGL render

[Antonio Vazquez]

Commit: f276b08714d9281a9ae80728b31ffd9a2b03e19e
Author: Antonio Vazquez
Date:   Sun Feb 4 20:05:45 2018 +0100
Branches: greasepencil-object
https://developer.blender.org/rBf276b08714d9281a9ae80728b31ffd9a2b03e19e

Convert colors to linear for OpenGL render

This is a workaround to convert the colors to linear space instead of sRGB for opengl render.

This can change in the future, but now this fix is required in order to produce the renders of Hero open movie.

===================================================================

M	source/blender/draw/engines/gpencil/gpencil_geom.c

===================================================================

diff --git a/source/blender/draw/engines/gpencil/gpencil_geom.c b/source/blender/draw/engines/gpencil/gpencil_geom.c
index c540440a34f..fdc75142f51 100644
--- a/source/blender/draw/engines/gpencil/gpencil_geom.c
+++ b/source/blender/draw/engines/gpencil/gpencil_geom.c
@@ -50,6 +50,22 @@
 
 #include "gpencil_engine.h"
 
+/* helper to convert color space to linear */
+static void gpencil_linear_colorspace(const float color[4], float r_color[4])
+{
+	const char *display_device;
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	Scene *scene = draw_ctx->scene;
+
+	display_device = scene->display_settings.display_device;
+	if ((DRW_state_is_image_render()) && (strcmp(display_device, "sRGB") == 0)) {
+		srgb_to_linearrgb_v4(r_color, color);
+	}
+	else {
+		copy_v4_v4(r_color, color);
+	}
+}
+
 /* set stroke point to vbo */
 static void gpencil_set_stroke_point(
         Gwn_VertBuf *vbo, float matrix[4][4], const bGPDspoint *pt, int idx,
@@ -58,12 +74,15 @@ static void gpencil_set_stroke_point(
         const float ink[4])
 {
 	float viewfpt[3];
-	
+	float space_color[4];
+
 	float alpha = ink[3] * pt->strength;
 	CLAMP(alpha, GPENCIL_STRENGTH_MIN, 1.0f);
 	float col[4];
 	ARRAY_SET_ITEMS(col, ink[0], ink[1], ink[2], alpha);
-	GWN_vertbuf_attr_set(vbo, color_id, idx, col);
+
+	gpencil_linear_colorspace(col, space_color);
+	GWN_vertbuf_attr_set(vbo, color_id, idx, space_color);
 
 	/* the thickness of the stroke must be affected by zoom, so a pixel scale is calculated */
 	mul_v3_m4v3(viewfpt, matrix, &pt->x);
@@ -92,6 +111,7 @@ Gwn_Batch *DRW_gpencil_get_point_geom(bGPDstroke *gps, short thickness, const fl
 	int idx = 0;
 	float alpha;
 	float col[4];
+	float space_color[4];
 
 	for (int i = 0; i < gps->totpoints; i++, pt++) {
 		/* set point */
@@ -101,7 +121,8 @@ Gwn_Batch *DRW_gpencil_get_point_geom(bGPDstroke *gps, short thickness, const fl
 
 		float thick = max_ff(pt->pressure * thickness, 1.0f);
 
-		GWN_vertbuf_attr_set(vbo, color_id, idx, col);
+		gpencil_linear_colorspace(col, space_color);
+		GWN_vertbuf_attr_set(vbo, color_id, idx, space_color);
 		GWN_vertbuf_attr_set(vbo, size_id, idx, &thick);
 		GWN_vertbuf_attr_set(vbo, pos_id, idx, &pt->x);
 		++idx;
@@ -586,6 +607,9 @@ static void gpencil_set_fill_point(
 Gwn_Batch *DRW_gpencil_get_fill_geom(bGPDstroke *gps, const float color[4])
 {
 	BLI_assert(gps->totpoints >= 3);
+	
+	float space_color[4];
+	gpencil_linear_colorspace(color, space_color);
 
 	/* Calculate triangles cache for filling area (must be done only after changes) */
 	if ((gps->flag & GP_STROKE_RECALC_CACHES) || (gps->tot_triangles == 0) || (gps->triangles == NULL)) {
@@ -610,7 +634,7 @@ Gwn_Batch *DRW_gpencil_get_fill_geom(bGPDstroke *gps, const float color[4])
 	for (int i = 0; i < gps->tot_triangles; i++, stroke_triangle++) {
 		for (int j = 0; j < 3; j++) {
 			gpencil_set_fill_point(
-			        vbo, idx, &gps->points[stroke_triangle->verts[j]], color, stroke_triangle->uv[j],
+			        vbo, idx, &gps->points[stroke_triangle->verts[j]], space_color, stroke_triangle->uv[j],
 			        pos_id, color_id, text_id);
 			++idx;
 		}