prepare for patchbay effects

src/engine/effect.h

@@ -0,0 +1,189 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2023 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _EFFECT_H
+#define _EFFECT_H
+
+#include <stdlib.h>
+#include "../ta-utils.h"
+
+class DivEngine;
+
+class DivEffect {
+  protected:
+    DivEngine* parent;
+  public:
+    /**
+     * fill a buffer with sound data.
+     * @param in pointers to input buffers.
+     * @param out pointers to output buffers.
+     * @param len the amount of samples in input and output.
+     */
+    virtual void acquire(float** in, float** out, size_t len);
+
+    /**
+     * reset the state of this effect.
+     */
+    virtual void reset();
+
+    /**
+     * get the number of inputs this effect requests.
+     * @return number of inputs. SHALL NOT be less than zero.
+     */
+    virtual int getInputCount();
+
+    /**
+     * get the number of outputs this effect provides.
+     * @return number of outputs. SHALL NOT be less than one.
+     */
+    virtual int getOutputCount();
+
+    /**
+     * called when the sample rate changes.
+     * @param rate the new sample rate.
+     */
+    virtual void rateChanged(double rate);
+
+    /**
+     * get the value of a parameter.
+     * @param param parameter ID.
+     * @return a String with the value.
+     * @throws std::out_of_range if the parameter ID is out of range.
+     */
+    virtual String getParam(size_t param);
+
+    /**
+     * set the value of a parameter.
+     * @param param parameter ID.
+     * @param value the value.
+     * @return whether the parameter was set successfully.
+     */
+    virtual bool setParam(size_t param, String value);
+
+    /**
+     * get a list of parameters.
+     * @return a C string with a list of parameters, or NULL if there are none.
+     * PARAMETER TYPES
+     * 
+     * Parameter
+     *   id:type:name:description:[...]
+     *   type may be one of the following:
+     *   - s: string
+     *   - i: integer
+     *   - I: integer slider
+     *   - r: integer list (radio button)
+     *   - R: integer list (combo box)
+     *   - h: integer hex
+     *   - f: float
+     *   - F: float slider
+     *   - d: double
+     *   - D: double slider
+     *   - b: boolean (checkbox)
+     *   - t: boolean (toggle button)
+     *   - x: X/Y integer
+     *   - X: X/Y float
+     *   - c: color (RGB)
+     *   - C: color (RGBA)
+     *   - B: button
+     *
+     * SameLine
+     *   !s
+     *
+     * Separator
+     *   ---
+     *
+     * Indent/Unindent
+     *   > Indent
+     *   < Unindent
+     *
+     * TreeNode
+     *   >> Begin
+     *   << End
+     *
+     * Tabs
+     *   >TABBAR   BeginTabBar
+     *   >TAB:name Begin
+     *   <TAB      End
+     *   <TABBAR   EndTabBar
+     *
+     * Text
+     *   TEXT:text (static text)
+     *   TEXTF:id (dynamic text)
+     *
+     * NOTES
+     *
+     * use a new line to separate parameters.
+     * use `\:` if you need a colon.
+     */
+    virtual const char* getParams();
+
+    /**
+     * get the number of parameters.
+     * @return count.
+     */
+    virtual size_t getParamCount();
+
+    /**
+     * get a dynamic text.
+     * @param id the text ID.
+     * @return a String with the text.
+     * @throws std::out_of_range if the text ID is out of range.
+     */
+    virtual String getDynamicText(size_t id);
+
+    /**
+     * load effect data.
+     * @param version effect data version. may be zero.
+     * @param data effect data. may be NULL.
+     * @param len effect data length. may be zero.
+     * @return whether loading was successful.
+     */
+    virtual bool load(unsigned short version, const unsigned char* data, size_t len);
+
+    /**
+     * save effect data.
+     * @param version effect data version.
+     * @param len effect data length.
+     * @return a pointer to effect data. this must be de-allocated manually.
+     *         may also return NULL if it can't save.
+     */
+    virtual unsigned char* save(unsigned short* version, size_t* len);
+
+    /**
+     * initialize this DivEffect.
+     * @param parent the parent DivEngine.
+     * @param version effect data version. may be zero.
+     * @param data effect data. may be NULL.
+     * @param len effect data length. may be zero.
+     * @return whether initialization was successful.
+     */
+    virtual bool init(DivEngine* parent, double rate, unsigned short version, const unsigned char* data, size_t len);
+
+    /**
+     * quit the DivEffect.
+     */
+    virtual void quit();
+
+    virtual ~DivEffect();
+};
+
+// additional notes:
+// - we don't have a GUI API yet, but that will be added when I make the plugin bridge.
+
+#endif