From b055488c71f91934f8f616c0f4b7e1ff85c985d3 Mon Sep 17 00:00:00 2001
From: Grazvydas Ignotas <notasas@gmail.com>
Date: Tue, 9 Oct 2012 21:57:39 +0300
Subject: [PATCH] op_gammatable: add a new tool to generate DSS gamma tables

---
 Makefile        |   4 +-
 op_gammatable.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++++
 op_gammatool.c  |   3 +-
 3 files changed, 106 insertions(+), 2 deletions(-)
 create mode 100644 op_gammatable.c

diff --git a/Makefile b/Makefile
index 7a9692a..ce1bbce 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ CFLAGS += -Wall -O2
 LDFLAGS += -s
 INSTALL ?= bin
 
-BIN = op_runfbapp op_gammatool op_test_inputs ofbset
+BIN = op_runfbapp op_gammatool op_gammatable op_test_inputs ofbset
 
 all: $(BIN)
 
@@ -14,6 +14,7 @@ clean:
 
 op_runfbapp: LDFLAGS += -lpthread -lX11
 op_test_inputs: LDFLAGS += -lpthread -lts
+op_gammatable: LDFLAGS += -lm
 
 $(INSTALL):
 	mkdir -p $(INSTALL)
@@ -21,6 +22,7 @@ $(INSTALL):
 install: $(INSTALL) $(BIN)
 	cp op_runfbapp $(INSTALL)/
 	cp op_gammatool $(INSTALL)/op_gammatool_bin
+	cp op_gammatable $(INSTALL)/
 	cp op_test_inputs $(INSTALL)/op_test_inputs_bin
 	cp ofbset $(INSTALL)/
 	cp scripts/op_gammatool $(INSTALL)/
diff --git a/op_gammatable.c b/op_gammatable.c
new file mode 100644
index 0000000..dd321ed
--- /dev/null
+++ b/op_gammatable.c
@@ -0,0 +1,101 @@
+/*
+ * op_gammatable - generate a gamma table for OMAP's DSS
+ *
+ * Copyright (c) 2012, Gražvydas Ignotas
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the organization nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+static void usage(const char *argv0)
+{
+	fprintf(stderr, "usage:\n");
+	fprintf(stderr, "%s [-n] {<gamma> | <gamma_r> <gamma_g> <gamma_b>}\n",
+		argv0);
+	exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+	unsigned int v, r, g, b;
+	float gamma[3] = { 0.f, };
+	int negative = 0, ptod = 0, half = 0;
+	int i, arg = 1;
+
+	if (argc < 2)
+		usage(argv[0]);
+	while (arg < argc && argv[arg][0] == '-') {
+		if (strcmp(argv[arg], "-h") == 0)
+			usage(argv[0]);
+		else if (strcmp(argv[arg], "-n") == 0)
+			negative = 1;
+		else if (strcmp(argv[arg], "-ptod") == 0)
+			ptod = 1;
+		else if (strcmp(argv[arg], "-half") == 0)
+			half = 1;
+		else
+			fprintf(stderr, "%s: ignoring %s\n",
+				argv[0], argv[arg]);
+		arg++;
+	}
+
+	if (argc - arg == 3) {
+		gamma[0] = atof(argv[arg++]);
+		gamma[1] = atof(argv[arg++]);
+		gamma[2] = atof(argv[arg++]);
+	}
+	else if (argc - arg == 1)
+		gamma[0] = gamma[1] = gamma[2] = atof(argv[arg++]);
+	else
+		usage(argv[0]);
+
+	if (gamma[0] <= 0.f || gamma[1] <= 0.f || gamma[2] <= 0.f) {
+		fprintf(stderr, "invalid arguments: %.3f %.3f %.3f\n",
+			gamma[0], gamma[1], gamma[2]);
+		usage(argv[0]);
+	}
+
+	for (i = 0; i < 256; i++) {
+		// based on http://www.teamten.com/lawrence/graphics/gamma/
+		r = (unsigned int) (255.f * powf((float)i / 255.f, 1.f / gamma[0]) + 0.5f);
+		g = (unsigned int) (255.f * powf((float)i / 255.f, 1.f / gamma[1]) + 0.5f);
+		b = (unsigned int) (255.f * powf((float)i / 255.f, 1.f / gamma[2]) + 0.5f);
+
+		v = (r << 16) | (g << 8) | b;
+		if (negative)
+			v ^= 0xffffff;
+		if (half)
+			v = (v >> 1) & 0x7f7f7f;
+		if (ptod)
+			v &= 0xff7fff;
+
+		printf("0x%06x ", v);
+	}
+	printf("\n");
+
+	return 0;
+}
diff --git a/op_gammatool.c b/op_gammatool.c
index 964ece3..224c222 100644
--- a/op_gammatool.c
+++ b/op_gammatool.c
@@ -1,6 +1,7 @@
 /*
+ * op_gammatool - pandora's LCD gamma adjustment tool
+ *
  * Copyright (c) 2010, Gražvydas Ignotas
- * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
-- 
2.39.2