Reduce unnecessary COW on Vector by make writing explicit

This commit makes operator[] on Vector const and adds a write proxy to it.  From
now on writes to Vectors need to happen through the .write proxy. So for
instance:

Vector<int> vec;
vec.push_back(10);
std::cout << vec[0] << std::endl;
vec.write[0] = 20;

Failing to use the .write proxy will cause a compilation error.

In addition COWable datatypes can now embed a CowData pointer to their data.
This means that String, CharString, and VMap no longer use or derive from
Vector.

_ALWAYS_INLINE_ and _FORCE_INLINE_ are now equivalent for debug and non-debug
builds. This is a lot faster for Vector in the editor and while running tests.
The reason why this difference used to exist is because force-inlined methods
used to give a bad debugging experience. After extensive testing with modern
compilers this is no longer the case.

3 files changed, 9 insertions, 9 deletions

diff --git a/servers/audio/effects/audio_effect_chorus.cpp b/servers/audio/effects/audio_effect_chorus.cpp
index f2f554a09b..fd9e3311e7 100644
--- a/servers/audio/effects/audio_effect_chorus.cpp
+++ b/servers/audio/effects/audio_effect_chorus.cpp
@@ -53,7 +53,7 @@ void AudioEffectChorusInstance::_process_chunk(const AudioFrame *p_src_frames, A
 
 	//fill ringbuffer
 	for (int i = 0; i < p_frame_count; i++) {
-		audio_buffer[(buffer_pos + i) & buffer_mask] = p_src_frames[i];
+		audio_buffer.write[(buffer_pos + i) & buffer_mask] = p_src_frames[i];
 		p_dst_frames[i] = p_src_frames[i] * base->dry;
 	}
 
@@ -175,7 +175,7 @@ Ref<AudioEffectInstance> AudioEffectChorus::instance() {
 	ins->buffer_pos = 0;
 	ins->audio_buffer.resize(ringbuff_size);
 	for (int i = 0; i < ringbuff_size; i++) {
-		ins->audio_buffer[i] = AudioFrame(0, 0);
+		ins->audio_buffer.write[i] = AudioFrame(0, 0);
 	}
 
 	return ins;
diff --git a/servers/audio/effects/audio_effect_eq.cpp b/servers/audio/effects/audio_effect_eq.cpp
index a30fca4e8d..cf8f7d3e16 100644
--- a/servers/audio/effects/audio_effect_eq.cpp
+++ b/servers/audio/effects/audio_effect_eq.cpp
@@ -70,7 +70,7 @@ Ref<AudioEffectInstance> AudioEffectEQ::instance() {
 	for (int i = 0; i < 2; i++) {
 		ins->bands[i].resize(eq.get_band_count());
 		for (int j = 0; j < ins->bands[i].size(); j++) {
-			ins->bands[i][j] = eq.get_band_processor(j);
+			ins->bands[i].write[j] = eq.get_band_processor(j);
 		}
 	}
 
@@ -79,7 +79,7 @@ Ref<AudioEffectInstance> AudioEffectEQ::instance() {
 
 void AudioEffectEQ::set_band_gain_db(int p_band, float p_volume) {
 	ERR_FAIL_INDEX(p_band, gain.size());
-	gain[p_band] = p_volume;
+	gain.write[p_band] = p_volume;
 }
 
 float AudioEffectEQ::get_band_gain_db(int p_band) const {
@@ -134,7 +134,7 @@ AudioEffectEQ::AudioEffectEQ(EQ::Preset p_preset) {
 	eq.set_preset_band_mode(p_preset);
 	gain.resize(eq.get_band_count());
 	for (int i = 0; i < gain.size(); i++) {
-		gain[i] = 0.0;
+		gain.write[i] = 0.0;
 		String name = "band_db/" + itos(eq.get_band_frequency(i)) + "_hz";
 		prop_band_map[name] = i;
 		band_names.push_back(name);
diff --git a/servers/audio/effects/eq.cpp b/servers/audio/effects/eq.cpp
index 9ef41191f5..b15fc7ecf4 100644
--- a/servers/audio/effects/eq.cpp
+++ b/servers/audio/effects/eq.cpp
@@ -108,9 +108,9 @@ void EQ::recalculate_band_coefficients() {
 
 		ERR_CONTINUE(roots == 0);
 
-		band[i].c1 = 2.0 * ((0.5 - r1) / 2.0);
-		band[i].c2 = 2.0 * r1;
-		band[i].c3 = 2.0 * (0.5 + r1) * cos(th);
+		band.write[i].c1 = 2.0 * ((0.5 - r1) / 2.0);
+		band.write[i].c2 = 2.0 * r1;
+		band.write[i].c3 = 2.0 * (0.5 + r1) * cos(th);
 		//printf("band %i, coefs = %f,%f,%f\n",i,(float)bands[i].c1,(float)bands[i].c2,(float)bands[i].c3);
 	}
 }
@@ -180,7 +180,7 @@ void EQ::set_bands(const Vector<float> &p_bands) {
 	band.resize(p_bands.size());
 	for (int i = 0; i < p_bands.size(); i++) {
 
-		band[i].freq = p_bands[i];
+		band.write[i].freq = p_bands[i];
 	}
 
 	recalculate_band_coefficients();