From 97cc7d9137b3c808ce3f56f675d1b95413245e3f Mon Sep 17 00:00:00 2001
From: bjorn <mail@bjornbyt.es>
Date: Tue, 20 Jun 2023 21:42:44 -0700
Subject: [PATCH] Fix issue with blend shape compute shader;

It was only copying the raw vertex data for the first blend shape,
not the first blend shape in each group.
---
 etc/shaders/blender.comp        | 3 ++-
 src/modules/graphics/graphics.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/etc/shaders/blender.comp b/etc/shaders/blender.comp
index b50f5aad..5b7b6569 100644
--- a/etc/shaders/blender.comp
+++ b/etc/shaders/blender.comp
@@ -10,6 +10,7 @@ layout(push_constant) uniform PushConstants {
   uint vertexCount;
   uint blendShapeCount;
   uint baseBlendVertex;
+  bool first;
 };
 
 struct ModelVertex {
@@ -36,7 +37,7 @@ void lovrmain() {
   uint vertexIndex = baseVertex + GlobalThreadID.x;
   uint blendVertexIndex = baseBlendVertex + GlobalThreadID.x;
 
-  ModelVertex vertex = baseBlendVertex == 0 ? rawVertices[vertexIndex] : vertices[vertexIndex];
+  ModelVertex vertex = first ? rawVertices[vertexIndex] : vertices[vertexIndex];
 
   for (uint i = 0; i < blendShapeCount; i++, blendVertexIndex += vertexCount) {
     float weight = weights[i / 4][i % 4];
diff --git a/src/modules/graphics/graphics.c b/src/modules/graphics/graphics.c
index 6ae6e1ad..81b57295 100644
--- a/src/modules/graphics/graphics.c
+++ b/src/modules/graphics/graphics.c
@@ -4206,6 +4206,7 @@ static void lovrModelAnimateVertices(Model* model) {
 
       for (uint32_t j = 0; j < group->count; j += chunkSize) {
         uint32_t count = MIN(group->count - j, chunkSize);
+        bool first = j == 0;
 
         MappedBuffer mapped = mapBuffer(&state.streamBuffers, chunkSize * sizeof(float), state.limits.uniformBufferAlign);
         memcpy(mapped.pointer, model->blendShapeWeights + group->index + j, count * sizeof(float));
@@ -4215,7 +4216,7 @@ static void lovrModelAnimateVertices(Model* model) {
         gpu_bundle_info bundleInfo = { layout, bindings, COUNTOF(bindings) };
         gpu_bundle_write(&bundle, &bundleInfo, 1);
 
-        uint32_t constants[] = { group->vertexIndex, group->vertexCount, count, blendBufferCursor };
+        uint32_t constants[] = { group->vertexIndex, group->vertexCount, count, blendBufferCursor, first };
         uint32_t subgroupSize = state.device.subgroupSize;
 
         gpu_push_constants(state.stream, shader->gpu, constants, sizeof(constants));