Fix T46189, draw style for waveforms occludes sequence strip text.

Used old (2.49 era) filled style for drawing here, with white color and
alpha blending.
Also changed drawing to do linear interpolation between samples instead
of ugly square wave in high zoom.
This could be improved upon, with real waveform drawing in higher zoom
levels, but I'll leave this for later since it may need some hacking on
audaspace level.

1 files changed, 24 insertions, 22 deletions

diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index 114e8d657d8..642c55df13f 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -198,7 +198,7 @@ static void drawseqwave(const bContext *C, SpaceSeq *sseq, Scene *scene, Sequenc
 		float yscale = (y2 - y1) / 2;
 		float samplestep;
 		float startsample, endsample;
-		float value;
+		float value1, value2;
 		bSound *sound = seq->sound;
 		
 		SoundWaveform *waveform;
@@ -238,35 +238,37 @@ static void drawseqwave(const bContext *C, SpaceSeq *sseq, Scene *scene, Sequenc
 		if (length > floor((waveform->length - startsample) / samplestep))
 			length = floor((waveform->length - startsample) / samplestep);
 
-		glBegin(GL_LINE_STRIP);
+		glColor4f(1.0f, 1.0f, 1.0f, 0.5);
+		glEnable(GL_BLEND);
+		glBegin(GL_TRIANGLE_STRIP);
 		for (i = 0; i < length; i++) {
-			pos = startsample + i * samplestep;
-
-			value = waveform->data[pos * 3];
-
-			for (j = pos + 1; (j < waveform->length) && (j < pos + samplestep); j++) {
-				if (value > waveform->data[j * 3])
-					value = waveform->data[j * 3];
-			}
-
-			glVertex2f(x1 + i * stepsize, ymid + value * yscale);
-		}
-		glEnd();
+			float sampleoffset = startsample + i * samplestep;
+			pos = sampleoffset;
 
-		glBegin(GL_LINE_STRIP);
-		for (i = 0; i < length; i++) {
-			pos = startsample + i * samplestep;
+			value1 = waveform->data[pos * 3];
+			value2 = waveform->data[pos * 3 + 1];
 
-			value = waveform->data[pos * 3 + 1];
+			if (samplestep >= 2.0f) {
+				for (j = pos + 1; (j < waveform->length) && (j < pos + samplestep); j++) {
+					if (value1 > waveform->data[j * 3])
+						value1 = waveform->data[j * 3];
 
-			for (j = pos + 1; (j < waveform->length) && (j < pos + samplestep); j++) {
-				if (value < waveform->data[j * 3 + 1])
-					value = waveform->data[j * 3 + 1];
+					if (value2 < waveform->data[j * 3 + 1])
+						value2 = waveform->data[j * 3 + 1];
+				}
+			}
+			else {
+				float f = sampleoffset - pos;
+				value1 = (1.0f - f) * value1 + f * waveform->data[pos * 3 + 3];
+				value2 = (1.0f - f) * value2 + f * waveform->data[pos * 3 + 4];
 			}
 
-			glVertex2f(x1 + i * stepsize, ymid + value * yscale);
+			/* max(value, -1) ensures that no sound gets drawn as a line */
+			glVertex2f(x1 + i * stepsize, ymid + value1 * yscale);
+			glVertex2f(x1 + i * stepsize, ymid + value2 * yscale);
 		}
 		glEnd();
+		glDisable(GL_BLEND);
 	}
 }