fix for float projection painting, now updating correctly.

This fix also allows for partial update of the image, speeding up painting. 
The different code path implemented will be used to upload high resolution images to OpenGL when onion branch is merged.
Due to conversion of float textures to/from sRGB, corrections made to brush color sampling to take account of the image profile. This is not 100% correct yet as texture images used for projection painting strokes are not converted to/from sRGB yet(This has been decided due to loss of precision for 8-bit formats). It will have to do for now, though.

last-minute update, exr image loading is broken, will fix asap

2 files changed, 134 insertions, 0 deletions

diff --git a/source/blender/imbuf/IMB_imbuf.h b/source/blender/imbuf/IMB_imbuf.h
index 1eefc58d4de..5d61452e149 100644
--- a/source/blender/imbuf/IMB_imbuf.h
+++ b/source/blender/imbuf/IMB_imbuf.h
@@ -327,7 +327,12 @@ int imb_get_anim_type(const char *name);
  */
 void IMB_de_interlace(struct ImBuf *ibuf);
 void IMB_interlace(struct ImBuf *ibuf);
+
+/* create char buffer, color corrected if necessary, for ImBufs that lack one */ 
 void IMB_rect_from_float(struct ImBuf *ibuf);
+/* create char buffer for part of the image, color corrected if necessary,
+   Changed part will be stored in buffer. This is expected to be used for texture painting updates */ 
+void IMB_partial_rect_from_float(struct ImBuf *ibuf, float *buffer, int x, int y, int w, int h);
 void IMB_float_from_rect(struct ImBuf *ibuf);
 void IMB_float_from_rect_simple(struct ImBuf *ibuf); /* no profile conversion */
 /* note, check that the conversion exists, only some are supported */
diff --git a/source/blender/imbuf/intern/divers.c b/source/blender/imbuf/intern/divers.c
index 6b35d7df397..90ee2692cf0 100644
--- a/source/blender/imbuf/intern/divers.c
+++ b/source/blender/imbuf/intern/divers.c
@@ -197,6 +197,135 @@ void IMB_rect_from_float(struct ImBuf *ibuf)
 	ibuf->userflags &= ~IB_RECT_INVALID;
 }
 
+ 
+
+/* converts from linear float to sRGB byte for part of the texture, buffer will hold the changed part */
+void IMB_partial_rect_from_float(struct ImBuf *ibuf,float *buffer, int x, int y, int w, int h)
+{
+	/* indices to source and destination image pixels */
+	float *srcFloatPxl;
+	unsigned char *dstBytePxl;
+	/* buffer index will fill buffer */
+	float *bufferIndex;
+
+	/* convenience pointers to start of image buffers */
+	float *init_srcFloatPxl = (float *)ibuf->rect_float;
+	unsigned char *init_dstBytePxl = (unsigned char *) ibuf->rect;
+
+	/* Dithering factor */
+	float dither= ibuf->dither / 255.0f;
+	/* respective attributes of image */
+	short profile= ibuf->profile;
+	int channels= ibuf->channels;
+	
+	int i, j;
+	
+	/*
+		if called -only- from GPU_paint_update_image this test will never fail
+		but leaving it here for better or worse
+	*/
+	if(init_srcFloatPxl==NULL || (buffer == NULL)){
+		return;
+	}
+	if(init_dstBytePxl==NULL) {
+		imb_addrectImBuf(ibuf);
+		init_dstBytePxl = (unsigned char *) ibuf->rect;
+	}
+	if(channels==1) {
+			for (j = 0; j < h; j++){
+				bufferIndex = buffer + w*j*4;
+				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x);
+				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl++, bufferIndex+=4) {
+					dstBytePxl[1]= dstBytePxl[2]= dstBytePxl[3]= dstBytePxl[0] = FTOCHAR(srcFloatPxl[0]);
+					bufferIndex[0] = bufferIndex[1] = bufferIndex[2] = bufferIndex[3] = srcFloatPxl[0];
+				}
+			}
+	}
+	else if (profile == IB_PROFILE_LINEAR_RGB) {
+		if(channels == 3) {
+			for (j = 0; j < h; j++){
+				bufferIndex = buffer + w*j*4;
+				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*3;
+				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=3, bufferIndex += 4) {
+					linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
+					F3TOCHAR4(bufferIndex, dstBytePxl);
+					bufferIndex[3]= 1.0;
+				}
+			}
+		}
+		else if (channels == 4) {
+			if (dither != 0.f) {
+				for (j = 0; j < h; j++){
+					bufferIndex = buffer + w*j*4;
+					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
+					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
+						const float d = (BLI_frand()-0.5f)*dither;
+						linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
+						bufferIndex[3] = srcFloatPxl[3];
+						add_v4_fl(bufferIndex, d);
+						F4TOCHAR4(bufferIndex, dstBytePxl);
+					}
+				}
+			} else {
+				for (j = 0; j < h; j++){
+					bufferIndex = buffer + w*j*4;
+					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
+					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
+						linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
+						bufferIndex[3]= srcFloatPxl[3];
+						F4TOCHAR4(bufferIndex, dstBytePxl);
+					}
+				}
+			}
+		}
+	}
+	else if(ELEM(profile, IB_PROFILE_NONE, IB_PROFILE_SRGB)) {
+		if(channels==3) {
+			for (j = 0; j < h; j++){
+				bufferIndex = buffer + w*j*4;
+				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*3;
+				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=3, bufferIndex+=4) {
+					copy_v3_v3(bufferIndex, srcFloatPxl);
+					F3TOCHAR4(bufferIndex, dstBytePxl);
+					bufferIndex[3] = 1.0;
+				}
+			}
+		}
+		else {
+			if (dither != 0.f) {
+				for (j = 0; j < h; j++){
+					bufferIndex = buffer + w*j*4;
+					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
+					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
+						const float d = (BLI_frand()-0.5f)*dither;
+						copy_v4_v4(bufferIndex, srcFloatPxl);
+						add_v4_fl(bufferIndex,d);
+						F4TOCHAR4(bufferIndex, dstBytePxl);
+					}
+				}
+			} else {
+				for (j = 0; j < h; j++){
+					bufferIndex = buffer + w*j*4;
+					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
+					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
+					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
+						copy_v4_v4(bufferIndex, srcFloatPxl);
+						F4TOCHAR4(bufferIndex, dstBytePxl);
+					}
+				}
+			}
+		}
+	}
+	/* ensure user flag is reset */
+	ibuf->userflags &= ~IB_RECT_INVALID;
+}
+
 static void imb_float_from_rect_nonlinear(struct ImBuf *ibuf, float *fbuf)
 {
 	float *tof = fbuf;