From edad38a5a2dca96f5bea513d11eccf1134046d47 Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Thu, 15 Jun 2017 07:06:13 +0200
Subject: made framebuffer segment a member of vga_mode_t, computing it once
 when vga_set_mode is called (because it will not change after every pixel)

---
 src/drivers/video/vga.c | 65 ++++++++++++++++++++++++-------------------------
 src/drivers/video/vga.h |  1 +
 2 files changed, 33 insertions(+), 33 deletions(-)

(limited to 'src/drivers')

diff --git a/src/drivers/video/vga.c b/src/drivers/video/vga.c
index 75a47f4..e3427b4 100644
--- a/src/drivers/video/vga.c
+++ b/src/drivers/video/vga.c
@@ -131,7 +131,8 @@ static vga_mode_t modes[] = {
 			0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
 			0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
 			0x41, 0x00, 0x0F, 0x00, 0x00
-		}
+		},
+		NULL
 	}
 };
 
@@ -161,34 +162,6 @@ static int get_matching_mode_idx( const vga_mode_t mode )
 	return -1;
 }
 
-bool vga_set_mode( vga_t *vga, const vga_mode_t mode )
-{
-	// do not allow unknown timings!
-	if( !vga_supports_mode( mode ) ) {
-		return false;
-	}
-
-	vga_mode_t matching_mode = modes[get_matching_mode_idx( mode )];
-
-	write_registers( vga, matching_mode.regs );
-
-	vga->mode = mode;
-
-	return true;
-}
-
-
-vga_color_t vga_make_RGB( int R, int G, int B )
-{
-	vga_color_t c;
-
-	c.R = R;
-	c.G = G;
-	c.B = B;
-
-	return c;
-}
-
 static uint8_t *get_frame_buffer_segment( vga_t *vga )
 {
 	port8_write( &vga->graphics_controller_index_port, 0x06 );
@@ -220,6 +193,35 @@ static uint8_t *get_frame_buffer_segment( vga_t *vga )
 	return segment;
 }
 
+bool vga_set_mode( vga_t *vga, const vga_mode_t mode )
+{
+	// do not allow unknown timings!
+	if( !vga_supports_mode( mode ) ) {
+		return false;
+	}
+
+	vga_mode_t matching_mode = modes[get_matching_mode_idx( mode )];
+
+	write_registers( vga, matching_mode.regs );
+
+	vga->mode = mode;
+	vga->mode.segment = get_frame_buffer_segment( vga );
+
+	return true;
+}
+
+
+vga_color_t vga_make_RGB( int R, int G, int B )
+{
+	vga_color_t c;
+
+	c.R = R;
+	c.G = G;
+	c.B = B;
+
+	return c;
+}
+
 static uint8_t get_color_index( const vga_color_t c )
 {
 	// TODO: for now white and black, standard VGA palette entries?
@@ -248,11 +250,8 @@ void vga_set_pixel( vga_t *vga, const int x, const int y, const vga_color_t colo
 
 	uint8_t color_idx = get_color_index( color );
 
-	uint8_t *segment = get_frame_buffer_segment( vga );
-
-	uint8_t *addr = segment + vga->mode.x * y + x;
+	uint8_t *addr = vga->mode.segment + vga->mode.x * y + x;
 
-//	printf( "%d %d 0x%X, 0x%X 0x%X\n", x, y, segment, addr, color_idx );
 	*addr = color_idx;
 }	
 
diff --git a/src/drivers/video/vga.h b/src/drivers/video/vga.h
index 7c710c3..6f70afa 100644
--- a/src/drivers/video/vga.h
+++ b/src/drivers/video/vga.h
@@ -17,6 +17,7 @@ typedef struct {
 	int y;
 	int color_depth;
 	uint8_t regs[NOF_MODE_REGS];
+	uint8_t *segment;
 } vga_mode_t;
 
 typedef struct {
-- 
cgit v1.2.3-54-g00ecf