1 files changed, 212 insertions, 4 deletions
diff --git a/apps/plugins/lib/gray_core.c b/apps/plugins/lib/gray_core.c
index 6cc33e05da..ef41e7e215 100644
--- a/apps/plugins/lib/gray_core.c
+++ b/apps/plugins/lib/gray_core.c
@@ -33,7 +33,117 @@ struct plugin_api *_gray_rb = NULL; /* global api struct pointer */
 struct _gray_info _gray_info;       /* global info structure */
 #ifndef SIMULATOR
 short _gray_random_buffer;          /* buffer for random number generator */
+#if CONFIG_LCD == LCD_SSD1815
+/* measured and interpolated curve */
+static const unsigned char lcdlinear[256] = {
+      0,   3,   5,   8,  11,  13,  16,  18,
+     21,  23,  26,  28,  31,  33,  36,  38,
+     40,  42,  45,  47,  49,  51,  53,  55,
+     57,  59,  60,  62,  64,  66,  67,  69,
+     70,  72,  73,  74,  76,  77,  78,  79,
+     81,  82,  83,  84,  85,  86,  87,  88,
+     88,  89,  90,  91,  92,  92,  93,  94,
+     95,  95,  96,  97,  97,  98,  99,  99,
+    100, 101, 102, 102, 103, 104, 104, 105,
+    106, 106, 107, 107, 108, 109, 109, 110,
+    111, 111, 112, 113, 113, 114, 114, 115,
+    116, 116, 117, 117, 118, 119, 119, 120,
+    120, 121, 121, 122, 122, 123, 123, 124,
+    124, 125, 125, 126, 126, 127, 127, 128,
+    128, 128, 129, 129, 130, 130, 131, 131,
+    132, 132, 133, 133, 133, 134, 134, 135,
+    135, 136, 136, 137, 137, 138, 138, 138,
+    139, 139, 140, 140, 141, 141, 142, 142,
+    143, 143, 144, 144, 145, 145, 146, 146,
+    147, 147, 148, 148, 148, 149, 149, 150,
+    150, 151, 151, 152, 152, 153, 153, 153,
+    154, 154, 155, 155, 156, 156, 157, 157,
+    158, 158, 158, 159, 159, 160, 160, 161,
+    161, 162, 162, 163, 163, 164, 164, 165,
+    165, 166, 167, 167, 168, 168, 169, 169,
+    170, 171, 171, 172, 173, 173, 174, 175,
+    176, 176, 177, 178, 179, 180, 181, 181,
+    182, 183, 184, 185, 186, 188, 189, 190,
+    191, 192, 194, 195, 196, 198, 199, 201,
+    202, 204, 205, 207, 209, 211, 213, 215,
+    217, 219, 222, 224, 226, 229, 231, 234,
+    236, 239, 242, 244, 247, 250, 252, 255
+};
+#elif CONFIG_LCD == LCD_S1D15E06
+/* measured and interpolated curve */
+static const unsigned char lcdlinear[256] = {
+      0,   5,  11,  16,  21,  27,  32,  37,
+     42,  47,  51,  56,  60,  64,  68,  72,
+     75,  78,  81,  84,  87,  89,  91,  93,
+     95,  96,  98,  99, 101, 102, 103, 104,
+    105, 106, 107, 108, 109, 110, 111, 111,
+    112, 113, 113, 114, 115, 115, 116, 117,
+    117, 118, 118, 119, 119, 120, 120, 121,
+    121, 122, 122, 123, 123, 124, 124, 125,
+    125, 126, 126, 127, 127, 127, 128, 128,
+    129, 129, 130, 130, 131, 131, 132, 132,
+    133, 133, 134, 134, 135, 135, 136, 136,
+    137, 137, 138, 138, 138, 139, 139, 140,
+    140, 141, 141, 141, 142, 142, 143, 143,
+    143, 144, 144, 145, 145, 145, 146, 146,
+    146, 147, 147, 147, 148, 148, 149, 149,
+    149, 150, 150, 150, 151, 151, 151, 152,
+    152, 153, 153, 153, 154, 154, 155, 155,
+    155, 156, 156, 157, 157, 157, 158, 158,
+    159, 159, 159, 160, 160, 161, 161, 162,
+    162, 162, 163, 163, 164, 164, 164, 165,
+    165, 166, 166, 167, 167, 167, 168, 168,
+    169, 169, 170, 170, 170, 171, 171, 172,
+    172, 173, 173, 174, 174, 175, 175, 176,
+    176, 177, 177, 178, 178, 179, 179, 180,
+    180, 181, 182, 182, 183, 184, 184, 185,
+    186, 186, 187, 188, 188, 189, 190, 191,
+    191, 192, 193, 194, 195, 196, 196, 197,
+    198, 199, 200, 201, 202, 203, 204, 205,
+    206, 207, 208, 209, 210, 211, 213, 214,
+    215, 216, 218, 219, 220, 222, 223, 225,
+    227, 228, 230, 232, 233, 235, 237, 239,
+    241, 243, 245, 247, 249, 251, 253, 255
+};
 #endif
+#else /* SIMULATOR */
+/* undo a (generic) PC display gamma of 2.0 to simulate target behaviour */
+static const unsigned char lcdlinear[256] = {
+      0,  16,  23,  28,  32,  36,  39,  42,
+     45,  48,  50,  53,  55,  58,  60,  62,
+     64,  66,  68,  70,  71,  73,  75,  77,
+     78,  80,  81,  83,  84,  86,  87,  89,
+     90,  92,  93,  94,  96,  97,  98, 100,
+    101, 102, 103, 105, 106, 107, 108, 109,
+    111, 112, 113, 114, 115, 116, 117, 118,
+    119, 121, 122, 123, 124, 125, 126, 127,
+    128, 129, 130, 131, 132, 133, 134, 135,
+    135, 136, 137, 138, 139, 140, 141, 142,
+    143, 144, 145, 145, 146, 147, 148, 149,
+    150, 151, 151, 152, 153, 154, 155, 156,
+    156, 157, 158, 159, 160, 160, 161, 162,
+    163, 164, 164, 165, 166, 167, 167, 168,
+    169, 170, 170, 171, 172, 173, 173, 174,
+    175, 176, 176, 177, 178, 179, 179, 180,
+    181, 181, 182, 183, 183, 184, 185, 186,
+    186, 187, 188, 188, 189, 190, 190, 191,
+    192, 192, 193, 194, 194, 195, 196, 196,
+    197, 198, 198, 199, 199, 200, 201, 201,
+    202, 203, 203, 204, 204, 205, 206, 206,
+    207, 208, 208, 209, 209, 210, 211, 211,
+    212, 212, 213, 214, 214, 215, 215, 216,
+    217, 217, 218, 218, 219, 220, 220, 221,
+    221, 222, 222, 223, 224, 224, 225, 225,
+    226, 226, 227, 228, 228, 229, 229, 230,
+    230, 231, 231, 232, 233, 233, 234, 234,
+    235, 235, 236, 236, 237, 237, 238, 238,
+    239, 240, 240, 241, 241, 242, 242, 243,
+    243, 244, 244, 245, 245, 246, 246, 247,
+    247, 248, 248, 249, 249, 250, 250, 251,
+    251, 252, 252, 253, 253, 254, 254, 255
+};
+#endif /* SIMULATOR */
 /* Prototypes */
 static inline void _deferred_update(void) __attribute__ ((always_inline));
@@ -84,6 +194,75 @@ static void _timer_isr(void)
 }
 #endif /* !SIMULATOR */
+/* fixed point exp() */
+static int exp_s16p16(int x)
+{
+    int t;
+    int y = 0x00010000;
+    
+    if (x == 0)
+    {
+        return y;
+    }
+    else if (x > 0)
+    {
+        t = x - 0x58b91; if (t >= 0) x = t, y <<= 8;
+        t = x - 0x2c5c8; if (t >= 0) x = t, y <<= 4;
+        t = x - 0x162e4; if (t >= 0) x = t, y <<= 2;
+        t = x - 0x0b172; if (t >= 0) x = t, y <<= 1;
+    }
+    else
+    {
+        t = x + 0x58b91; if (t < 0) x = t, y >>= 8;
+        t = x + 0x2c5c8; if (t < 0) x = t, y >>= 4;
+        t = x + 0x162e4; if (t < 0) x = t, y >>= 2;
+        t = x + 0x0b172; if (t < 0) x = t, y >>= 1;
+        x += 0x0b172;                      y >>= 1;
+    }
+    t = x - 0x067cd; if (t >= 0) x = t, y += y >> 1;
+    t = x - 0x03920; if (t >= 0) x = t, y += y >> 2;
+    t = x - 0x01e27; if (t >= 0) x = t, y += y >> 3;
+    t = x - 0x00f85; if (t >= 0) x = t, y += y >> 4;
+    t = x - 0x007e1; if (t >= 0) x = t, y += y >> 5;
+    t = x - 0x003f8; if (t >= 0) x = t, y += y >> 6;
+    t = x - 0x001fe; if (t >= 0) x = t, y += y >> 7;
+    if (x & 0x100)               y += y >> 8;
+    if (x & 0x080)               y += y >> 9;
+    if (x & 0x040)               y += y >> 10;
+    if (x & 0x020)               y += y >> 11;
+    if (x & 0x010)               y += y >> 12;
+    if (x & 0x008)               y += y >> 13;
+    if (x & 0x004)               y += y >> 14;
+    if (x & 0x002)               y += y >> 15;
+    if (x & 0x001)               y += y >> 16;
+    return y;
+}
+/* fixed point log() */
+int log_s16p16(int x)
+{
+    int t;
+    int y = 0xa65af;
+    if (x < 0x00008000) x <<=16,                        y -= 0xb1721;
+    if (x < 0x00800000) x <<= 8,                        y -= 0x58b91;
+    if (x < 0x08000000) x <<= 4,                        y -= 0x2c5c8;
+    if (x < 0x20000000) x <<= 2,                        y -= 0x162e4;
+    if (x < 0x40000000) x <<= 1,                        y -= 0x0b172;
+    t = x + (x >> 1); if ((t & 0x80000000) == 0) x = t, y -= 0x067cd;
+    t = x + (x >> 2); if ((t & 0x80000000) == 0) x = t, y -= 0x03920;
+    t = x + (x >> 3); if ((t & 0x80000000) == 0) x = t, y -= 0x01e27;
+    t = x + (x >> 4); if ((t & 0x80000000) == 0) x = t, y -= 0x00f85;
+    t = x + (x >> 5); if ((t & 0x80000000) == 0) x = t, y -= 0x007e1;
+    t = x + (x >> 6); if ((t & 0x80000000) == 0) x = t, y -= 0x003f8;
+    t = x + (x >> 7); if ((t & 0x80000000) == 0) x = t, y -= 0x001fe;
+    x = 0x80000000 - x;
+    y -= x >> 15;
+    return y;
+}
 /* Initialise the framework and prepare the greyscale display buffer
 arguments:
@@ -97,6 +276,8 @@ static void _timer_isr(void)
   width     = width in pixels  (1..LCD_WIDTH)
   bheight   = height in LCD pixel-block units (8 pixels) (1..LCD_HEIGHT/8)
   depth     = number of bitplanes to use (1..32).
+   gamma     = gamma value as s8p8 fixed point. gamma <= 0 means no
+               correction at all, i.e. no LCD linearisation as well.
 result:
   = depth  if there was enough memory
@@ -128,12 +309,14 @@ static void _timer_isr(void)
   one situation where it will consume more memory on the sim than on the
   target: if you're allocating a low depth (< 8) without buffering. */
 int gray_init(struct plugin_api* newrb, unsigned char *gbuf, long gbuf_size,
-              bool buffered, int width, int bheight, int depth, long *buf_taken)
+              bool buffered, int width, int bheight, int depth, int gamma,
+              long *buf_taken)
 {
-    int possible_depth;
+    int possible_depth, i;
    long plane_size, buftaken;
+    unsigned data;
 #ifndef SIMULATOR
-    int i, j;
+    int j;
 #endif
    _gray_rb = newrb;
@@ -240,8 +423,33 @@ int gray_init(struct plugin_api* newrb, unsigned char *gbuf, long gbuf_size,
    }
 #endif
+    /* precalculate the value -> pattern index conversion table, taking 
+       linearisation and gamma correction into account */
+    if (gamma <= 0)
+    {
+        for (i = 0; i < 256; i++)
+        {
+            data = MULU16(depth, lcdlinear[i]) + 127;
+            _gray_info.idxtable[i] = (data + (data >> 8)) >> 8;
+                                      /* approx. data / 255 */
+        }
+    }
+    else
+    {
+        for (i = 0; i < 256; i++)
+        {
+            data = exp_s16p16(gamma * (log_s16p16(i * 257 + 1) >> 8));
+            data = (data - (data >> 8)) >> 8; /* approx. data /= 257 */
+            data = MULU16(depth, lcdlinear[data]) + 127;
+            _gray_info.idxtable[i] = (data + (data >> 8)) >> 8;
+                                      /* approx. data / 255 */
+        }
+    }
+    _gray_info.fg_index = 0;
+    _gray_info.bg_index = depth;
    _gray_info.fg_brightness = 0;
-    _gray_info.bg_brightness = depth;
+    _gray_info.bg_brightness = 255;
    _gray_info.drawmode = DRMODE_SOLID;
    _gray_info.curfont = FONT_SYSFIXED;

diff --git a/apps/plugins/lib/gray_core.c b/apps/plugins/lib/gray_core.c index 6cc33e05da..ef41e7e215 100644 --- a/apps/plugins/lib/gray_core.c +++ b/apps/plugins/lib/gray_core.c
@@ -33,7 +33,117 @@ struct plugin_api _gray_rb = NULL; / global api struct pointer */
33	struct _gray_info _gray_info; /* global info structure */	33	struct _gray_info _gray_info; /* global info structure */
34	#ifndef SIMULATOR	34	#ifndef SIMULATOR
35	short _gray_random_buffer; /* buffer for random number generator */	35	short _gray_random_buffer; /* buffer for random number generator */
		36
		37	#if CONFIG_LCD == LCD_SSD1815
		38	/* measured and interpolated curve */
		39	static const unsigned char lcdlinear[256] = {
		40	0, 3, 5, 8, 11, 13, 16, 18,
		41	21, 23, 26, 28, 31, 33, 36, 38,
		42	40, 42, 45, 47, 49, 51, 53, 55,
		43	57, 59, 60, 62, 64, 66, 67, 69,
		44	70, 72, 73, 74, 76, 77, 78, 79,
		45	81, 82, 83, 84, 85, 86, 87, 88,
		46	88, 89, 90, 91, 92, 92, 93, 94,
		47	95, 95, 96, 97, 97, 98, 99, 99,
		48	100, 101, 102, 102, 103, 104, 104, 105,
		49	106, 106, 107, 107, 108, 109, 109, 110,
		50	111, 111, 112, 113, 113, 114, 114, 115,
		51	116, 116, 117, 117, 118, 119, 119, 120,
		52	120, 121, 121, 122, 122, 123, 123, 124,
		53	124, 125, 125, 126, 126, 127, 127, 128,
		54	128, 128, 129, 129, 130, 130, 131, 131,
		55	132, 132, 133, 133, 133, 134, 134, 135,
		56	135, 136, 136, 137, 137, 138, 138, 138,
		57	139, 139, 140, 140, 141, 141, 142, 142,
		58	143, 143, 144, 144, 145, 145, 146, 146,
		59	147, 147, 148, 148, 148, 149, 149, 150,
		60	150, 151, 151, 152, 152, 153, 153, 153,
		61	154, 154, 155, 155, 156, 156, 157, 157,
		62	158, 158, 158, 159, 159, 160, 160, 161,
		63	161, 162, 162, 163, 163, 164, 164, 165,
		64	165, 166, 167, 167, 168, 168, 169, 169,
		65	170, 171, 171, 172, 173, 173, 174, 175,
		66	176, 176, 177, 178, 179, 180, 181, 181,
		67	182, 183, 184, 185, 186, 188, 189, 190,
		68	191, 192, 194, 195, 196, 198, 199, 201,
		69	202, 204, 205, 207, 209, 211, 213, 215,
		70	217, 219, 222, 224, 226, 229, 231, 234,
		71	236, 239, 242, 244, 247, 250, 252, 255
		72	};
		73	#elif CONFIG_LCD == LCD_S1D15E06
		74	/* measured and interpolated curve */
		75	static const unsigned char lcdlinear[256] = {
		76	0, 5, 11, 16, 21, 27, 32, 37,
		77	42, 47, 51, 56, 60, 64, 68, 72,
		78	75, 78, 81, 84, 87, 89, 91, 93,
		79	95, 96, 98, 99, 101, 102, 103, 104,
		80	105, 106, 107, 108, 109, 110, 111, 111,
		81	112, 113, 113, 114, 115, 115, 116, 117,
		82	117, 118, 118, 119, 119, 120, 120, 121,
		83	121, 122, 122, 123, 123, 124, 124, 125,
		84	125, 126, 126, 127, 127, 127, 128, 128,
		85	129, 129, 130, 130, 131, 131, 132, 132,
		86	133, 133, 134, 134, 135, 135, 136, 136,
		87	137, 137, 138, 138, 138, 139, 139, 140,
		88	140, 141, 141, 141, 142, 142, 143, 143,
		89	143, 144, 144, 145, 145, 145, 146, 146,
		90	146, 147, 147, 147, 148, 148, 149, 149,
		91	149, 150, 150, 150, 151, 151, 151, 152,
		92	152, 153, 153, 153, 154, 154, 155, 155,
		93	155, 156, 156, 157, 157, 157, 158, 158,
		94	159, 159, 159, 160, 160, 161, 161, 162,
		95	162, 162, 163, 163, 164, 164, 164, 165,
		96	165, 166, 166, 167, 167, 167, 168, 168,
		97	169, 169, 170, 170, 170, 171, 171, 172,
		98	172, 173, 173, 174, 174, 175, 175, 176,
		99	176, 177, 177, 178, 178, 179, 179, 180,
		100	180, 181, 182, 182, 183, 184, 184, 185,
		101	186, 186, 187, 188, 188, 189, 190, 191,
		102	191, 192, 193, 194, 195, 196, 196, 197,
		103	198, 199, 200, 201, 202, 203, 204, 205,
		104	206, 207, 208, 209, 210, 211, 213, 214,
		105	215, 216, 218, 219, 220, 222, 223, 225,
		106	227, 228, 230, 232, 233, 235, 237, 239,
		107	241, 243, 245, 247, 249, 251, 253, 255
		108	};
36	#endif	109	#endif
		110	#else /* SIMULATOR */
		111	/* undo a (generic) PC display gamma of 2.0 to simulate target behaviour */
		112	static const unsigned char lcdlinear[256] = {
		113	0, 16, 23, 28, 32, 36, 39, 42,
		114	45, 48, 50, 53, 55, 58, 60, 62,
		115	64, 66, 68, 70, 71, 73, 75, 77,
		116	78, 80, 81, 83, 84, 86, 87, 89,
		117	90, 92, 93, 94, 96, 97, 98, 100,
		118	101, 102, 103, 105, 106, 107, 108, 109,
		119	111, 112, 113, 114, 115, 116, 117, 118,
		120	119, 121, 122, 123, 124, 125, 126, 127,
		121	128, 129, 130, 131, 132, 133, 134, 135,
		122	135, 136, 137, 138, 139, 140, 141, 142,
		123	143, 144, 145, 145, 146, 147, 148, 149,
		124	150, 151, 151, 152, 153, 154, 155, 156,
		125	156, 157, 158, 159, 160, 160, 161, 162,
		126	163, 164, 164, 165, 166, 167, 167, 168,
		127	169, 170, 170, 171, 172, 173, 173, 174,
		128	175, 176, 176, 177, 178, 179, 179, 180,
		129	181, 181, 182, 183, 183, 184, 185, 186,
		130	186, 187, 188, 188, 189, 190, 190, 191,
		131	192, 192, 193, 194, 194, 195, 196, 196,
		132	197, 198, 198, 199, 199, 200, 201, 201,
		133	202, 203, 203, 204, 204, 205, 206, 206,
		134	207, 208, 208, 209, 209, 210, 211, 211,
		135	212, 212, 213, 214, 214, 215, 215, 216,
		136	217, 217, 218, 218, 219, 220, 220, 221,
		137	221, 222, 222, 223, 224, 224, 225, 225,
		138	226, 226, 227, 228, 228, 229, 229, 230,
		139	230, 231, 231, 232, 233, 233, 234, 234,
		140	235, 235, 236, 236, 237, 237, 238, 238,
		141	239, 240, 240, 241, 241, 242, 242, 243,
		142	243, 244, 244, 245, 245, 246, 246, 247,
		143	247, 248, 248, 249, 249, 250, 250, 251,
		144	251, 252, 252, 253, 253, 254, 254, 255
		145	};
		146	#endif /* SIMULATOR */
37		147
38	/* Prototypes */	148	/* Prototypes */
39	static inline void _deferred_update(void) __attribute__ ((always_inline));	149	static inline void _deferred_update(void) __attribute__ ((always_inline));
@@ -84,6 +194,75 @@ static void _timer_isr(void)
84	}	194	}
85	#endif /* !SIMULATOR */	195	#endif /* !SIMULATOR */
86		196
		197	/* fixed point exp() */
		198	static int exp_s16p16(int x)
		199	{
		200	int t;
		201	int y = 0x00010000;
		202
		203	if (x == 0)
		204	{
		205	return y;
		206	}
		207	else if (x > 0)
		208	{
		209	t = x - 0x58b91; if (t >= 0) x = t, y <<= 8;
		210	t = x - 0x2c5c8; if (t >= 0) x = t, y <<= 4;
		211	t = x - 0x162e4; if (t >= 0) x = t, y <<= 2;
		212	t = x - 0x0b172; if (t >= 0) x = t, y <<= 1;
		213	}
		214	else
		215	{
		216	t = x + 0x58b91; if (t < 0) x = t, y >>= 8;
		217	t = x + 0x2c5c8; if (t < 0) x = t, y >>= 4;
		218	t = x + 0x162e4; if (t < 0) x = t, y >>= 2;
		219	t = x + 0x0b172; if (t < 0) x = t, y >>= 1;
		220	x += 0x0b172; y >>= 1;
		221	}
		222	t = x - 0x067cd; if (t >= 0) x = t, y += y >> 1;
		223	t = x - 0x03920; if (t >= 0) x = t, y += y >> 2;
		224	t = x - 0x01e27; if (t >= 0) x = t, y += y >> 3;
		225	t = x - 0x00f85; if (t >= 0) x = t, y += y >> 4;
		226	t = x - 0x007e1; if (t >= 0) x = t, y += y >> 5;
		227	t = x - 0x003f8; if (t >= 0) x = t, y += y >> 6;
		228	t = x - 0x001fe; if (t >= 0) x = t, y += y >> 7;
		229	if (x & 0x100) y += y >> 8;
		230	if (x & 0x080) y += y >> 9;
		231	if (x & 0x040) y += y >> 10;
		232	if (x & 0x020) y += y >> 11;
		233	if (x & 0x010) y += y >> 12;
		234	if (x & 0x008) y += y >> 13;
		235	if (x & 0x004) y += y >> 14;
		236	if (x & 0x002) y += y >> 15;
		237	if (x & 0x001) y += y >> 16;
		238
		239	return y;
		240	}
		241
		242	/* fixed point log() */
		243	int log_s16p16(int x)
		244	{
		245	int t;
		246	int y = 0xa65af;
		247
		248	if (x < 0x00008000) x <<=16, y -= 0xb1721;
		249	if (x < 0x00800000) x <<= 8, y -= 0x58b91;
		250	if (x < 0x08000000) x <<= 4, y -= 0x2c5c8;
		251	if (x < 0x20000000) x <<= 2, y -= 0x162e4;
		252	if (x < 0x40000000) x <<= 1, y -= 0x0b172;
		253	t = x + (x >> 1); if ((t & 0x80000000) == 0) x = t, y -= 0x067cd;
		254	t = x + (x >> 2); if ((t & 0x80000000) == 0) x = t, y -= 0x03920;
		255	t = x + (x >> 3); if ((t & 0x80000000) == 0) x = t, y -= 0x01e27;
		256	t = x + (x >> 4); if ((t & 0x80000000) == 0) x = t, y -= 0x00f85;
		257	t = x + (x >> 5); if ((t & 0x80000000) == 0) x = t, y -= 0x007e1;
		258	t = x + (x >> 6); if ((t & 0x80000000) == 0) x = t, y -= 0x003f8;
		259	t = x + (x >> 7); if ((t & 0x80000000) == 0) x = t, y -= 0x001fe;
		260	x = 0x80000000 - x;
		261	y -= x >> 15;
		262
		263	return y;
		264	}
		265
87	/* Initialise the framework and prepare the greyscale display buffer	266	/* Initialise the framework and prepare the greyscale display buffer
88		267
89	arguments:	268	arguments:
@@ -97,6 +276,8 @@ static void _timer_isr(void)
97	width = width in pixels (1..LCD_WIDTH)	276	width = width in pixels (1..LCD_WIDTH)
98	bheight = height in LCD pixel-block units (8 pixels) (1..LCD_HEIGHT/8)	277	bheight = height in LCD pixel-block units (8 pixels) (1..LCD_HEIGHT/8)
99	depth = number of bitplanes to use (1..32).	278	depth = number of bitplanes to use (1..32).
		279	gamma = gamma value as s8p8 fixed point. gamma <= 0 means no
		280	correction at all, i.e. no LCD linearisation as well.
100		281
101	result:	282	result:
102	= depth if there was enough memory	283	= depth if there was enough memory
@@ -128,12 +309,14 @@ static void _timer_isr(void)
128	one situation where it will consume more memory on the sim than on the	309	one situation where it will consume more memory on the sim than on the
129	target: if you're allocating a low depth (< 8) without buffering. */	310	target: if you're allocating a low depth (< 8) without buffering. */
130	int gray_init(struct plugin_api* newrb, unsigned char *gbuf, long gbuf_size,	311	int gray_init(struct plugin_api* newrb, unsigned char *gbuf, long gbuf_size,
131	bool buffered, int width, int bheight, int depth, long *buf_taken)	312	bool buffered, int width, int bheight, int depth, int gamma,
		313	long *buf_taken)
132	{	314	{
133	int possible_depth;	315	int possible_depth, i;
134	long plane_size, buftaken;	316	long plane_size, buftaken;
		317	unsigned data;
135	#ifndef SIMULATOR	318	#ifndef SIMULATOR
136	int i, j;	319	int j;
137	#endif	320	#endif
138		321
139	_gray_rb = newrb;	322	_gray_rb = newrb;
@@ -240,8 +423,33 @@ int gray_init(struct plugin_api* newrb, unsigned char *gbuf, long gbuf_size,
240	}	423	}
241	#endif	424	#endif
242		425
		426	/* precalculate the value -> pattern index conversion table, taking
		427	linearisation and gamma correction into account */
		428	if (gamma <= 0)
		429	{
		430	for (i = 0; i < 256; i++)
		431	{
		432	data = MULU16(depth, lcdlinear[i]) + 127;
		433	_gray_info.idxtable[i] = (data + (data >> 8)) >> 8;
		434	/* approx. data / 255 */
		435	}
		436	}
		437	else
		438	{
		439	for (i = 0; i < 256; i++)
		440	{
		441	data = exp_s16p16(gamma * (log_s16p16(i * 257 + 1) >> 8));
		442	data = (data - (data >> 8)) >> 8; /* approx. data /= 257 */
		443	data = MULU16(depth, lcdlinear[data]) + 127;
		444	_gray_info.idxtable[i] = (data + (data >> 8)) >> 8;
		445	/* approx. data / 255 */
		446	}
		447	}
		448
		449	_gray_info.fg_index = 0;
		450	_gray_info.bg_index = depth;
243	_gray_info.fg_brightness = 0;	451	_gray_info.fg_brightness = 0;
244	_gray_info.bg_brightness = depth;	452	_gray_info.bg_brightness = 255;
245	_gray_info.drawmode = DRMODE_SOLID;	453	_gray_info.drawmode = DRMODE_SOLID;
246	_gray_info.curfont = FONT_SYSFIXED;	454	_gray_info.curfont = FONT_SYSFIXED;
247		455