Allow looped animation to be used safely with old clients

fixes #12657

diff --git a/src/client/particles.cpp b/src/client/particles.cpp
index 95d3c20216e43b21ce4c634ea430f5bd85d8c21a..85baee7cd21d75c7c38e82e8da2b0b66868cb762 100644 (file)
--- a/src/client/particles.cpp
+++ b/src/client/particles.cpp
@@ -555,6 +555,7 @@ void ParticleSpawner::spawnParticle(ClientEnvironment *env, float radius,
 
        // synchronize animation length with particle life if desired
        if (pp.animation.type != TAT_NONE) {
+               // FIXME: this should be moved into a TileAnimationParams class method
                if (pp.animation.type == TAT_VERTICAL_FRAMES &&
                        pp.animation.vertical_frames.length < 0) {
                        auto& a = pp.animation.vertical_frames;

diff --git a/src/particles.cpp b/src/particles.cpp
index 19b3418b7139e05e0199865315dc6250270caf26..e495ecd0395459ac31e44ae426d5f7c9dac6e7d0 100644 (file)
--- a/src/particles.cpp
+++ b/src/particles.cpp
@@ -127,7 +127,7 @@ void ParticleParameters::serialize(std::ostream &os, u16 protocol_ver) const
        os << serializeString32(texture.string);
        writeU8(os, vertical);
        writeU8(os, collision_removal);
-       animation.serialize(os, 6); /* NOT the protocol ver */
+       animation.serialize(os, protocol_ver);
        writeU8(os, glow);
        writeU8(os, object_collision);
        writeU16(os, node.param0);
@@ -160,7 +160,7 @@ void ParticleParameters::deSerialize(std::istream &is, u16 protocol_ver)
        texture.string     = deSerializeString32(is);
        vertical           = readU8(is);
        collision_removal  = readU8(is);
-       animation.deSerialize(is, 6); /* NOT the protocol ver */
+       animation.deSerialize(is, protocol_ver);
        glow               = readU8(is);
        object_collision   = readU8(is);
 

diff --git a/src/tileanimation.cpp b/src/tileanimation.cpp
index a79a36e5796629743a776d01aa2e1910e5705205..025d27d91054b81df9745f06a7670c5466c82d82 100644 (file)
--- a/src/tileanimation.cpp
+++ b/src/tileanimation.cpp
@@ -19,21 +19,27 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "tileanimation.h"
 #include "util/serialize.h"
 
-void TileAnimationParams::serialize(std::ostream &os, u16 protocol_version) const
+void TileAnimationParams::serialize(std::ostream &os, u16 protocol_ver) const
 {
+       // The particle code overloads the length parameter so that negative numbers
+       // indicate an extra feature which old clients don't understand (crash).
+       // In hindsight it would have been better to use an extra parameter for this
+       // but we're stuck with this now.
+       const bool need_abs = protocol_ver < 40;
+
        writeU8(os, type);
        if (type == TAT_VERTICAL_FRAMES) {
                writeU16(os, vertical_frames.aspect_w);
                writeU16(os, vertical_frames.aspect_h);
-               writeF32(os, vertical_frames.length);
+               writeF32(os, need_abs ? fabs(vertical_frames.length) : vertical_frames.length);
        } else if (type == TAT_SHEET_2D) {
                writeU8(os, sheet_2d.frames_w);
                writeU8(os, sheet_2d.frames_h);
-               writeF32(os, sheet_2d.frame_length);
+               writeF32(os, need_abs ? fabs(sheet_2d.frame_length) : sheet_2d.frame_length);
        }
 }
 
-void TileAnimationParams::deSerialize(std::istream &is, u16 protocol_version)
+void TileAnimationParams::deSerialize(std::istream &is, u16 protocol_ver)
 {
        type = (TileAnimationType) readU8(is);
 

diff --git a/src/tileanimation.h b/src/tileanimation.h
index 0449de0b8bb28f1e08149b2fa1ed9acc7558e1a6..45b91655ec104304eb07b9401f4cf3bad52afdbd 100644 (file)
--- a/src/tileanimation.h
+++ b/src/tileanimation.h
@@ -50,8 +50,8 @@ struct TileAnimationParams
                } sheet_2d;
        };
 
-       void serialize(std::ostream &os, u16 protocol_version) const;
-       void deSerialize(std::istream &is, u16 protocol_version);
+       void serialize(std::ostream &os, u16 protocol_ver) const;
+       void deSerialize(std::istream &is, u16 protocol_ver);
        void determineParams(v2u32 texture_size, int *frame_count, int *frame_length_ms,
                        v2u32 *frame_size) const;
        void getTextureModifer(std::ostream &os, v2u32 texture_size, int frame) const;