implement generic controller

6 files changed, 194 insertions, 141 deletions

diff --git a/.gitignore b/.gitignore
index 24b0cb0..c78dfd9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,5 +3,7 @@
 *.sublime-workspace
 
 # general files
+controller
+controller-static
 *.o
 *~
diff --git a/Makefile b/Makefile
index bb9ca92..f1d4d1c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,17 +1,25 @@
 TARGET=controller
 
-all: $(TARGET) $(TARGET)-static
+CC=gcc
+CFLAGS=-std=gnu99 -Wall -O2
+
+LD=gcc
+LDFLAGS=-O2
 
+SOURCES=$(wildcard *.c)
+OBJECTS=$(addsuffix .o, $(basename $(SOURCES)))
 
-$(TARGET): $(TARGET).o
-	gcc -Wall -o $@ $< `sdl2-config --libs`
 
-$(TARGET)-static: $(TARGET).o
-	gcc -Wall -o $@ $< `sdl2-config --static-libs`
+all: $(TARGET) $(TARGET)-static
+
+$(TARGET): $(OBJECTS)
+	$(LD) $(LDFLAGS) -o $@ $^ `sdl2-config --libs`
 
+$(TARGET)-static: $(OBJECTS)
+	$(LD) $(LDFLAGS) -o $@ $^ `sdl2-config --static-libs`
 
 %.o: %.c
-	gcc -Wall `sdl2-config --cflags` -o $@ -c $<
+	$(CC) $(CFLAGS) `sdl2-config --cflags` -o $@ -c $<
 
 clean:
 	rm -f *.o
diff --git a/controller.c b/controller.c
deleted file mode 100644
index c5be026..0000000
--- a/controller.c
+++ /dev/null
@@ -1,135 +0,0 @@
-#include <stdio.h>
-#include <stdbool.h>
-#include "SDL.h"
-
-void joystick_open(int id, SDL_Joystick* joystick) {
-
-    joystick=SDL_JoystickOpen(id);
-  
-    if(joystick) {
-        fprintf(stderr, "Opened joystick %d\n", id);
-        fprintf(stderr, "Name: %s\n", SDL_JoystickName(joystick));
-        fprintf(stderr, "Number of axes: %d\n", SDL_JoystickNumAxes(joystick));
-        fprintf(stderr, "Number of buttons: %d\n", SDL_JoystickNumButtons(joystick));
-        fprintf(stderr, "Number of balls: %d\n", SDL_JoystickNumBalls(joystick));
-    } else {
-        fprintf(stderr, "Couldn't open joystick %d\n", id);
-    }
-}
-
-void joystick_close(SDL_Joystick* joystick) {
-    if (SDL_JoystickGetAttached(joystick)) {
-        SDL_JoystickClose(joystick);
-    }
-}
-
-int main(int argc, char *argv[]) { 
-
-    //initialize joystick library
-    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) < 0) {
-        fprintf(stderr, "Couldn't initialize SDL joystick: %s\n", SDL_GetError());
-        exit(1);
-    }
-
-    //id of controlling joystick
-    int joystick_id = 0;
-
-    int throttle = 0;
-
-    //pointer to joystick in use
-    SDL_Joystick* joystick = NULL;
-
-    //event loop
-    SDL_Event e;
-    bool cont = true;
-    while (cont) {
-
-        while( SDL_WaitEventTimeout(&e, 500)) {
-            switch( e.type ) {
-
-            case SDL_JOYDEVICEADDED:
-                if (e.jdevice.which == joystick_id) {
-                    fprintf(stderr, "Joystick connected\n");
-                    joystick_open(joystick_id, joystick);
-                }
-                break;
-
-            case SDL_JOYDEVICEREMOVED:
-                if (e.jdevice.which == joystick_id) {
-                    fprintf(stderr, "Joystick disconnected\n");
-                    joystick_close(joystick);
-                }
-                break;
-
-            case SDL_JOYAXISMOTION:
-                fprintf(stderr, "axis event\n");
-                fprintf(stderr, "%d\n", e.jaxis.value);
-                break;
-            case SDL_JOYHATMOTION:
-                fprintf(stderr, "hat event\n");
-                break;
-
-            case SDL_JOYBUTTONDOWN:
-                switch (e.jbutton.button) {
-                case 0:
-                    throttle = 12;
-                    break;
-                case 4:
-                    throttle -= 1;
-                    break;
-                case 5:
-                    throttle += 1;
-                    break;
-                case 6:
-                    throttle -= 25;
-                    break;
-                case 7:
-                    throttle += 25;
-                    break;
-                default:
-                    break;
-                }
-
-                fprintf(stderr, "button down\n");
-                break;
-
-            case SDL_JOYBUTTONUP:
-                fprintf(stderr, "button up\n");
-                break;
-
-            case SDL_QUIT:
-                cont = false;
-                break;
-
-            default:
-                fprintf(stderr,"Unsupported event type: %d\n", e.type);
-                break;
-            }
-
-            if (throttle < 0) {
-                throttle = 0;
-            }
-            if (throttle > 255) {
-                throttle = 255;
-            }
-            unsigned char tc = (unsigned char) throttle;
-            fprintf(stderr, "%u\n", tc);
-            printf("%u\n", tc);
-            fflush(stdout);
-
-        }
-
-        unsigned char tc = (unsigned char) throttle;
-        //fwrite(&tc, 1, 1, stdout);
-        //fflush(stdout);
-        printf("%u\n", tc);
-        fflush(stdout);
-
-        
-
-        //print_control_data(&c);
-        //printf("--\n");
-    }
-
-    return 0;
-}
\ No newline at end of file
diff --git a/controller.h b/controller.h
new file mode 100644
index 0000000..0f81c66
--- /dev/null
+++ b/controller.h
@@ -0,0 +1,40 @@
+#ifndef CONTROLLER_H
+#define CONTROLLER_H
+
+#include <stdbool.h>
+#include <stddef.h>
+
+#define AXIS_MIN -32768
+#define AXIS_MAX 32767
+#define CHANNELS 5
+
+typedef unsigned char channel_t;
+
+inline channel_t axis_to_channel(int value) {
+	long centered = (long) value - AXIS_MIN;
+	return (channel_t) (centered * 255 / (AXIS_MAX - AXIS_MIN));
+}
+
+inline channel_t channel_clamp(channel_t channel, channel_t min, channel_t max) {
+    channel_t upper = (channel < max) ? channel : max;
+    return (min < upper) ? upper : min;
+}
+
+inline void channel_increase(channel_t* channels, size_t channel_index, channel_t step, channel_t min, channel_t max) {
+    channel_t current = channels[channel_index];
+    channel_t next = channel_clamp(current + step, min, max);
+    channels[channel_index] = next;
+}
+
+inline void channel_decrease(channel_t* channels, size_t channel_index, channel_t step, channel_t min, channel_t max) {
+	channel_t current = channels[channel_index];
+    channel_t next = channel_clamp(current - step, min, max);
+    channels[channel_index] = next;
+}
+
+void channel_reset(channel_t* channels);
+void event_axis(channel_t* channels, int axis, int value);
+void event_button(channel_t* channels, int button, bool value);
+
+
+#endif
\ No newline at end of file
diff --git a/generic.c b/generic.c
new file mode 100644
index 0000000..8c32a97
--- /dev/null
+++ b/generic.c
@@ -0,0 +1,41 @@
+#include "controller.h"
+
+#define CHANNEL_THROTTLE 0
+
+#define THROTTLE_MIN 12
+#define THROTTLE_MAX 255
+
+void channel_reset(channel_t* channels) {
+	channels[0] = THROTTLE_MIN;
+	channels[1] = 127;
+	channels[2] = 127;
+	channels[3] = 127;
+	channels[4] = 127;
+}
+void event_axis(channel_t* channels, int axis, int value) {
+	channels[axis+1] = axis_to_channel(value);
+}
+void event_button(channel_t* channels, int button, bool value) {
+	if (value) {
+		switch(button) {
+		case 0:
+			channel_reset(channels);
+			break;
+		case 4:
+			channel_decrease(channels, CHANNEL_THROTTLE, 1, THROTTLE_MIN, THROTTLE_MAX);
+			break;
+		case 5:
+			channel_increase(channels, CHANNEL_THROTTLE, 1, THROTTLE_MIN, THROTTLE_MAX);
+			break;
+		case 6:
+			channel_decrease(channels, CHANNEL_THROTTLE, 10, THROTTLE_MIN, THROTTLE_MAX);
+			break;
+		case 7:
+			channel_increase(channels, CHANNEL_THROTTLE, 10, THROTTLE_MIN, THROTTLE_MAX);
+			break;
+		default:
+			break;
+		}
+
+	}
+}
\ No newline at end of file
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..ff0673a
--- /dev/null
+++ b/main.c
@@ -0,0 +1,97 @@
+#include <stdio.h>
+#include <SDL.h>
+#include "controller.h"
+
+static int run(int joystick_id, int timeout, bool debug);
+static void print_channels(channel_t* channels, bool debug);
+
+int main(int argc, char *argv[]) { 
+
+    //initialize joystick library
+    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) < 0) {
+        fprintf(stderr, "Couldn't initialize SDL joystick subsystem: %s\n", SDL_GetError());
+        exit(1);
+    }
+
+    run(0, 500, true);
+
+   
+    return 0;
+}
+
+static int run(int joystick_id, int timeout, bool debug) {
+
+    channel_t channels[CHANNELS];
+    channel_reset(channels);
+
+    //pointer to joystick in use
+    SDL_Joystick* joystick = NULL;
+
+    //event loop
+    SDL_Event e;
+    bool cont = true;
+    while (cont) {
+
+        if(SDL_WaitEventTimeout(&e, timeout)) {
+            switch( e.type ) {
+
+            case SDL_JOYDEVICEADDED:
+                if (e.jdevice.which == joystick_id) {
+                    fprintf(stderr, "Joystick %d connected\n", e.jdevice.which);
+                    joystick=SDL_JoystickOpen(e.jdevice.which);
+                    if(joystick) {
+                        fprintf(stderr, "Opened joystick %d\n", e.jdevice.which);
+                        fprintf(stderr, "Name: %s\n", SDL_JoystickName(joystick));
+                        fprintf(stderr, "Number of axes: %d\n", SDL_JoystickNumAxes(joystick));
+                        fprintf(stderr, "Number of buttons: %d\n", SDL_JoystickNumButtons(joystick));
+                        fprintf(stderr, "Number of balls: %d\n", SDL_JoystickNumBalls(joystick));
+                    } else {
+                        fprintf(stderr, "Couldn't open joystick %d\n", e.jdevice.which);
+                    }
+                }
+                break;
+
+            case SDL_JOYDEVICEREMOVED:
+                if (e.jdevice.which == joystick_id) {
+                    if (SDL_JoystickGetAttached(joystick)) {
+                        SDL_JoystickClose(joystick);
+                    }
+                    fprintf(stderr, "Joystick %d disconnected\n", e.jdevice.which);
+                }
+                break;
+
+            case SDL_JOYAXISMOTION:
+                event_axis(channels, e.jaxis.axis, e.jaxis.value);
+                break;
+
+            case SDL_JOYBUTTONDOWN:
+                event_button(channels, e.jbutton.button, true);
+                break;
+                
+            case SDL_JOYBUTTONUP:
+                event_button(channels, e.jbutton.button, false);
+                break;
+
+            case SDL_QUIT:
+                cont = false;
+                break;
+
+            default:
+                fprintf(stderr,"Unsupported event type: %d\n", e.type);
+                break;
+            }
+            
+        }
+        print_channels(channels, debug);
+    }
+    return 0;
+}
+
+void print_channels(channel_t* channels, bool debug) {
+    for(size_t i=0; i < CHANNELS; ++i) {
+        fprintf(stdout, "%u\n", channels[i]);
+        fprintf(stderr, "channel %zu: %u\n", i, channels[i]);
+    }
+    fflush(stdout);
+    fflush(stderr);
+}
\ No newline at end of file