Color Management, Stage 2: Switch color pipeline to use OpenColorIO

Replace old color pipeline which was supporting linear/sRGB color spaces
only with OpenColorIO-based pipeline.

This introduces two configurable color spaces:

- Input color space for images and movie clips. This space is used to convert
  images/movies from color space in which file is saved to Blender's linear
  space (for float images, byte images are not internally converted, only input
  space is stored for such images and used later).

  This setting could be found in image/clip data block settings.

- Display color space which defines space in which particular display is working.

  This settings could be found in scene's Color Management panel.

When render result is being displayed on the screen, apart from converting image
to display space, some additional conversions could happen.

This conversions are:

- View, which defines tone curve applying before display transformation.
  These are different ways to view the image on the same display device.
  For example it could be used to emulate film view on sRGB display.

- Exposure affects on image exposure before tone map is applied.

- Gamma is post-display gamma correction, could be used to match particular
  display gamma.

- RGB curves are user-defined curves which are applying before display
  transformation, could be used for different purposes.

All this settings by default are only applying on render result and does not
affect on other images. If some particular image needs to be affected by this
transformation, "View as Render" setting of image data block should be set to
truth. Movie clips are always affected by all display transformations.

This commit also introduces configurable color space in which sequencer is
working. This setting could be found in scene's Color Management panel and
it should be used if such stuff as grading needs to be done in color space
different from sRGB (i.e. when Film view on sRGB display is use, using VD16
space as sequencer's internal space would make grading working in space
which is close to the space using for display).

Some technical notes:

- Image buffer's float buffer is now always in linear space, even if it was
  created from 16bit byte images.

- Space of byte buffer is stored in image buffer's rect_colorspace property.

- Profile of image buffer was removed since it's not longer meaningful.

- OpenGL and GLSL is supposed to always work in sRGB space. It is possible
  to support other spaces, but it's quite large project which isn't so
  much important.

- Legacy Color Management option disabled is emulated by using None display.
  It could have some regressions, but there's no clear way to avoid them.

- If OpenColorIO is disabled on build time, it should make blender behaving
  in the same way as previous release with color management enabled.

More details could be found at this page (more details would be added soon):
http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.64/Color_Management

--
Thanks to Xavier Thomas, Lukas Toene for initial work on OpenColorIO
integration and to Brecht van Lommel for some further development and code/
usecase review!

1 files changed, 76 insertions, 51 deletions

diff --git a/source/blender/editors/space_image/image_draw.c b/source/blender/editors/space_image/image_draw.c
index e293264c021..638a2ac6681 100644
--- a/source/blender/editors/space_image/image_draw.c
+++ b/source/blender/editors/space_image/image_draw.c
@@ -51,6 +51,7 @@
 
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
+#include "IMB_colormanagement.h"
 
 #include "BKE_context.h"
 #include "BKE_global.h"
@@ -70,6 +71,8 @@
 #include "UI_resources.h"
 #include "UI_view2d.h"
 
+#include "WM_api.h"
+#include "WM_types.h"
 
 #include "RE_pipeline.h"
 
@@ -77,27 +80,6 @@
 
 #define HEADER_HEIGHT 18
 
-static void image_verify_buffer_float(Image *ima, ImBuf *ibuf, int color_manage)
-{
-	/* detect if we need to redo the curve map.
-	 * ibuf->rect is zero for compositor and render results after change 
-	 * convert to 32 bits always... drawing float rects isn't supported well (atis)
-	 *
-	 * NOTE: if float buffer changes, we have to manually remove the rect
-	 */
-
-	if (ibuf->rect_float && (ibuf->rect == NULL || (ibuf->userflags & IB_RECT_INVALID)) ) {
-		if (color_manage) {
-			if (ima && ima->source == IMA_SRC_VIEWER)
-				ibuf->profile = IB_PROFILE_LINEAR_RGB;
-		}
-		else
-			ibuf->profile = IB_PROFILE_NONE;
-
-		IMB_rect_from_float(ibuf);
-	}
-}
-
 static void draw_render_info(Scene *scene, Image *ima, ARegion *ar)
 {
 	RenderResult *rr;
@@ -112,7 +94,7 @@ static void draw_render_info(Scene *scene, Image *ima, ARegion *ar)
 }
 
 /* used by node view too */
-void ED_image_draw_info(ARegion *ar, int color_manage, int channels, int x, int y,
+void ED_image_draw_info(Scene *scene, ARegion *ar, int color_manage, int use_default_view, int channels, int x, int y,
                         const unsigned char cp[4], const float fp[4], int *zp, float *zpf)
 {
 	char str[256];
@@ -209,6 +191,20 @@ void ED_image_draw_info(ARegion *ar, int color_manage, int channels, int x, int
 			BLF_draw_ascii(blf_mono_font, str, sizeof(str));
 			dx += BLF_width(blf_mono_font, str);
 		}
+
+		if (color_manage && channels == 4) {
+			float pixel[4];
+
+			if (use_default_view)
+				IMB_colormanagement_pixel_to_display_space_v4(pixel, fp,  NULL, &scene->display_settings);
+			else
+				IMB_colormanagement_pixel_to_display_space_v4(pixel, fp,  &scene->view_settings, &scene->display_settings);
+
+			BLI_snprintf(str, sizeof(str), "  |  CM  R:%-.4f  G:%-.4f  B:%-.4f", pixel[0], pixel[1], pixel[2]);
+			BLF_position(blf_mono_font, dx, 6, 0);
+			BLF_draw_ascii(blf_mono_font, str, sizeof(str));
+			dx += BLF_width(blf_mono_font, str);
+		}
 	}
 	
 	/* color rectangle */
@@ -252,11 +248,15 @@ void ED_image_draw_info(ARegion *ar, int color_manage, int channels, int x, int
 	}
 
 	if (color_manage) {
-		linearrgb_to_srgb_v4(finalcol, col);
+		if (use_default_view)
+			IMB_colormanagement_pixel_to_display_space_v4(finalcol, col,  NULL, &scene->display_settings);
+		else
+			IMB_colormanagement_pixel_to_display_space_v4(finalcol, col,  &scene->view_settings, &scene->display_settings);
 	}
 	else {
 		copy_v4_v4(finalcol, col);
 	}
+
 	glDisable(GL_BLEND);
 	glColor3fv(finalcol);
 	dx += 5;
@@ -418,10 +418,9 @@ static void sima_draw_zbuffloat_pixels(Scene *scene, float x1, float y1, int rec
 	MEM_freeN(rectf);
 }
 
-static void draw_image_buffer(SpaceImage *sima, ARegion *ar, Scene *scene, Image *ima, ImBuf *ibuf, float fx, float fy, float zoomx, float zoomy)
+static void draw_image_buffer(const bContext *C, SpaceImage *sima, ARegion *ar, Scene *scene, ImBuf *ibuf, float fx, float fy, float zoomx, float zoomy)
 {
 	int x, y;
-	int color_manage = scene->r.color_mgt_flag & R_COLOR_MANAGEMENT;
 
 	/* set zoom */
 	glPixelZoom(zoomx, zoomy);
@@ -445,6 +444,9 @@ static void draw_image_buffer(SpaceImage *sima, ARegion *ar, Scene *scene, Image
 			sima_draw_zbuffloat_pixels(scene, x, y, ibuf->x, ibuf->y, ibuf->rect_float);
 	}
 	else {
+		unsigned char *display_buffer;
+		void *cache_handle;
+
 		if (sima->flag & SI_USE_ALPHA) {
 			fdrawcheckerboard(x, y, x + ibuf->x * zoomx, y + ibuf->y * zoomy);
 
@@ -452,17 +454,17 @@ static void draw_image_buffer(SpaceImage *sima, ARegion *ar, Scene *scene, Image
 			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 		}
 
-		/* we don't draw floats buffers directly but
-		 * convert them, and optionally apply curves */
-		image_verify_buffer_float(ima, ibuf, color_manage);
+		display_buffer = IMB_display_buffer_acquire_ctx(C, ibuf, &cache_handle);
 
-		if (ibuf->rect)
-			glaDrawPixelsSafe(x, y, ibuf->x, ibuf->y, ibuf->x, GL_RGBA, GL_UNSIGNED_BYTE, ibuf->rect);
+		if (display_buffer)
+			glaDrawPixelsSafe(x, y, ibuf->x, ibuf->y, ibuf->x, GL_RGBA, GL_UNSIGNED_BYTE, display_buffer);
 #if 0
 		else
 			glaDrawPixelsSafe(x, y, ibuf->x, ibuf->y, ibuf->x, GL_RGBA, GL_FLOAT, ibuf->rect_float);
 #endif
-		
+
+		IMB_display_buffer_release(cache_handle);
+
 		if (sima->flag & SI_USE_ALPHA)
 			glDisable(GL_BLEND);
 	}
@@ -471,14 +473,14 @@ static void draw_image_buffer(SpaceImage *sima, ARegion *ar, Scene *scene, Image
 	glPixelZoom(1.0f, 1.0f);
 }
 
-static unsigned int *get_part_from_ibuf(ImBuf *ibuf, short startx, short starty, short endx, short endy)
+static unsigned int *get_part_from_buffer(unsigned int *buffer, int width, short startx, short starty, short endx, short endy)
 {
 	unsigned int *rt, *rp, *rectmain;
 	short y, heigth, len;
 
 	/* the right offset in rectot */
 
-	rt = ibuf->rect + (starty * ibuf->x + startx);
+	rt = buffer + (starty * width + startx);
 
 	len = (endx - startx);
 	heigth = (endy - starty);
@@ -487,7 +489,7 @@ static unsigned int *get_part_from_ibuf(ImBuf *ibuf, short startx, short starty,
 	
 	for (y = 0; y < heigth; y++) {
 		memcpy(rp, rt, len * 4);
-		rt += ibuf->x;
+		rt += width;
 		rp += len;
 	}
 	return rectmain;
@@ -495,28 +497,34 @@ static unsigned int *get_part_from_ibuf(ImBuf *ibuf, short startx, short starty,
 
 static void draw_image_buffer_tiled(SpaceImage *sima, ARegion *ar, Scene *scene, Image *ima, ImBuf *ibuf, float fx, float fy, float zoomx, float zoomy)
 {
+	unsigned char *display_buffer;
 	unsigned int *rect;
 	int dx, dy, sx, sy, x, y;
-	int color_manage = scene->r.color_mgt_flag & R_COLOR_MANAGEMENT;
+	void *cache_handle;
 
 	/* verify valid values, just leave this a while */
 	if (ima->xrep < 1) return;
 	if (ima->yrep < 1) return;
-	
+
+	if (ima->flag & IMA_VIEW_AS_RENDER)
+		display_buffer = IMB_display_buffer_acquire(ibuf, &scene->view_settings, &scene->display_settings, &cache_handle);
+	else
+		display_buffer = IMB_display_buffer_acquire(ibuf, NULL, &scene->display_settings, &cache_handle);
+
+	if (!display_buffer)
+		return;
+
 	glPixelZoom(zoomx, zoomy);
 
 	if (sima->curtile >= ima->xrep * ima->yrep)
 		sima->curtile = ima->xrep * ima->yrep - 1;
 	
-	/* create char buffer from float if needed */
-	image_verify_buffer_float(ima, ibuf, color_manage);
-
 	/* retrieve part of image buffer */
 	dx = ibuf->x / ima->xrep;
 	dy = ibuf->y / ima->yrep;
 	sx = (sima->curtile % ima->xrep) * dx;
 	sy = (sima->curtile / ima->xrep) * dy;
-	rect = get_part_from_ibuf(ibuf, sx, sy, sx + dx, sy + dy);
+	rect = get_part_from_buffer((unsigned int*)display_buffer, ibuf->x, sx, sy, sx + dx, sy + dy);
 	
 	/* draw repeated */
 	for (sy = 0; sy + dy <= ibuf->y; sy += dy) {
@@ -529,10 +537,12 @@ static void draw_image_buffer_tiled(SpaceImage *sima, ARegion *ar, Scene *scene,
 
 	glPixelZoom(1.0f, 1.0f);
 
+	IMB_display_buffer_release(cache_handle);
+
 	MEM_freeN(rect);
 }
 
-static void draw_image_buffer_repeated(SpaceImage *sima, ARegion *ar, Scene *scene, Image *ima, ImBuf *ibuf, float zoomx, float zoomy)
+static void draw_image_buffer_repeated(const bContext *C, SpaceImage *sima, ARegion *ar, Scene *scene, Image *ima, ImBuf *ibuf, float zoomx, float zoomy)
 {
 	const double time_current = PIL_check_seconds_timer();
 
@@ -549,7 +559,7 @@ static void draw_image_buffer_repeated(SpaceImage *sima, ARegion *ar, Scene *sce
 			if (ima && (ima->tpageflag & IMA_TILES))
 				draw_image_buffer_tiled(sima, ar, scene, ima, ibuf, x, y, zoomx, zoomy);
 			else
-				draw_image_buffer(sima, ar, scene, ima, ibuf, x, y, zoomx, zoomy);
+				draw_image_buffer(C, sima, ar, scene, ibuf, x, y, zoomx, zoomy);
 
 			/* only draw until running out of time */
 			if ((PIL_check_seconds_timer() - time_current) > 0.25)
@@ -632,22 +642,35 @@ static void draw_image_view_tool(Scene *scene)
 }
 #endif
 
-static unsigned char *get_alpha_clone_image(Scene *scene, int *width, int *height)
+static unsigned char *get_alpha_clone_image(const bContext *C, Scene *scene, int *width, int *height)
 {
 	Brush *brush = paint_brush(&scene->toolsettings->imapaint.paint);
 	ImBuf *ibuf;
 	unsigned int size, alpha;
+	unsigned char *display_buffer;
 	unsigned char *rect, *cp;
+	void *cache_handle;
 
 	if (!brush || !brush->clone.image)
 		return NULL;
 	
 	ibuf = BKE_image_get_ibuf(brush->clone.image, NULL);
 
-	if (!ibuf || !ibuf->rect)
+	if (!ibuf)
 		return NULL;
 
-	rect = MEM_dupallocN(ibuf->rect);
+	display_buffer = IMB_display_buffer_acquire_ctx(C, ibuf, &cache_handle);
+
+	if (!display_buffer) {
+		IMB_display_buffer_release(cache_handle);
+
+		return NULL;
+	}
+
+	rect = MEM_dupallocN(display_buffer);
+
+	IMB_display_buffer_release(cache_handle);
+
 	if (!rect)
 		return NULL;
 
@@ -666,7 +689,7 @@ static unsigned char *get_alpha_clone_image(Scene *scene, int *width, int *heigh
 	return rect;
 }
 
-static void draw_image_paint_helpers(ARegion *ar, Scene *scene, float zoomx, float zoomy)
+static void draw_image_paint_helpers(const bContext *C, ARegion *ar, Scene *scene, float zoomx, float zoomy)
 {
 	Brush *brush;
 	int x, y, w, h;
@@ -677,7 +700,7 @@ static void draw_image_paint_helpers(ARegion *ar, Scene *scene, float zoomx, flo
 	if (brush && (brush->imagepaint_tool == PAINT_TOOL_CLONE)) {
 		/* this is not very efficient, but glDrawPixels doesn't allow
 		 * drawing with alpha */
-		clonerect = get_alpha_clone_image(scene, &w, &h);
+		clonerect = get_alpha_clone_image(C, scene, &w, &h);
 
 		if (clonerect) {
 			UI_view2d_to_region_no_clip(&ar->v2d, brush->clone.offset[0], brush->clone.offset[1], &x, &y);
@@ -698,8 +721,10 @@ static void draw_image_paint_helpers(ARegion *ar, Scene *scene, float zoomx, flo
 
 /* draw main image area */
 
-void draw_image_main(SpaceImage *sima, ARegion *ar, Scene *scene)
+void draw_image_main(const bContext *C, ARegion *ar)
 {
+	SpaceImage *sima = CTX_wm_space_image(C);
+	Scene *scene = CTX_data_scene(C);
 	Image *ima;
 	ImBuf *ibuf;
 	float zoomx, zoomy;
@@ -748,15 +773,15 @@ void draw_image_main(SpaceImage *sima, ARegion *ar, Scene *scene)
 	if (ibuf == NULL)
 		ED_region_grid_draw(ar, zoomx, zoomy);
 	else if (sima->flag & SI_DRAW_TILE)
-		draw_image_buffer_repeated(sima, ar, scene, ima, ibuf, zoomx, zoomy);
+		draw_image_buffer_repeated(C, sima, ar, scene, ima, ibuf, zoomx, zoomy);
 	else if (ima && (ima->tpageflag & IMA_TILES))
 		draw_image_buffer_tiled(sima, ar, scene, ima, ibuf, 0.0f, 0.0, zoomx, zoomy);
 	else
-		draw_image_buffer(sima, ar, scene, ima, ibuf, 0.0f, 0.0f, zoomx, zoomy);
+		draw_image_buffer(C, sima, ar, scene, ibuf, 0.0f, 0.0f, zoomx, zoomy);
 
 	/* paint helpers */
 	if (sima->mode == SI_MODE_PAINT)
-		draw_image_paint_helpers(ar, scene, zoomx, zoomy);
+		draw_image_paint_helpers(C, ar, scene, zoomx, zoomy);
 
 
 	/* XXX integrate this code */