content_cao: Support texture animation for upright_sprite (#10020)

3 files changed, 41 insertions, 3 deletions

diff --git a/src/client/content_cao.cpp b/src/client/content_cao.cpp
index 4f949f6b0..88688d18c 100644
--- a/src/client/content_cao.cpp
+++ b/src/client/content_cao.cpp
@@ -1176,6 +1176,7 @@ void GenericCAO::updateTexturePos()
 		int row = m_tx_basepos.Y;
 		int col = m_tx_basepos.X;
 
+		// Yawpitch goes rightwards
 		if (m_tx_select_horiz_by_yawpitch) {
 			if (cam_to_entity.Y > 0.75)
 				col += 5;
@@ -1206,6 +1207,27 @@ void GenericCAO::updateTexturePos()
 		float tys = m_tx_size.Y;
 		setBillboardTextureMatrix(m_spritenode, txs, tys, col, row);
 	}
+
+	else if (m_meshnode) {
+		if (m_prop.visual == "upright_sprite") {
+			int row = m_tx_basepos.Y;
+			int col = m_tx_basepos.X;
+
+			// Animation goes downwards
+			row += m_anim_frame;
+
+			const auto &tx = m_tx_size;
+			v2f t[4] = { // cf. vertices in GenericCAO::addToScene()
+				tx * v2f(col+1, row+1),
+				tx * v2f(col, row+1),
+				tx * v2f(col, row),
+				tx * v2f(col+1, row),
+			};
+			auto mesh = m_meshnode->getMesh();
+			setMeshBufferTextureCoords(mesh->getMeshBuffer(0), t, 4);
+			setMeshBufferTextureCoords(mesh->getMeshBuffer(1), t, 4);
+		}
+	}
 }
 
 // Do not pass by reference, see header.
@@ -1247,7 +1269,7 @@ void GenericCAO::updateTextures(std::string mod)
 		}
 	}
 
-	if (m_animated_meshnode) {
+	else if (m_animated_meshnode) {
 		if (m_prop.visual == "mesh") {
 			for (u32 i = 0; i < m_prop.textures.size() &&
 					i < m_animated_meshnode->getMaterialCount(); ++i) {
@@ -1296,8 +1318,8 @@ void GenericCAO::updateTextures(std::string mod)
 			}
 		}
 	}
-	if(m_meshnode)
-	{
+
+	else if (m_meshnode) {
 		if(m_prop.visual == "cube")
 		{
 			for (u32 i = 0; i < 6; ++i)
diff --git a/src/client/mesh.cpp b/src/client/mesh.cpp
index e1ec22068..2400a374c 100644
--- a/src/client/mesh.cpp
+++ b/src/client/mesh.cpp
@@ -203,6 +203,15 @@ void setMeshColor(scene::IMesh *mesh, const video::SColor &color)
 		setMeshBufferColor(mesh->getMeshBuffer(j), color);
 }
 
+void setMeshBufferTextureCoords(scene::IMeshBuffer *buf, const v2f *uv, u32 count)
+{
+	const u32 stride = getVertexPitchFromType(buf->getVertexType());
+	assert(buf->getVertexCount() >= count);
+	u8 *vertices = (u8 *) buf->getVertices();
+	for (u32 i = 0; i < count; i++)
+		((video::S3DVertex*) (vertices + i * stride))->TCoords = uv[i];
+}
+
 template <typename F>
 static void applyToMesh(scene::IMesh *mesh, const F &fn)
 {
diff --git a/src/client/mesh.h b/src/client/mesh.h
index 103c61e45..dbc091a06 100644
--- a/src/client/mesh.h
+++ b/src/client/mesh.h
@@ -58,6 +58,13 @@ void setMeshBufferColor(scene::IMeshBuffer *buf, const video::SColor &color);
 */
 void setMeshColor(scene::IMesh *mesh, const video::SColor &color);
 
+
+/*
+	Sets texture coords for vertices in the mesh buffer.
+	`uv[]` must have `count` elements
+*/
+void setMeshBufferTextureCoords(scene::IMeshBuffer *buf, const v2f *uv, u32 count);
+
 /*
 	Set a constant color for an animated mesh
 */