Codechange: [Blitter] Change DrawLine to be templated

This is remove per-pixel overheads due to use of the SetPixel virtual
method.
These overheads included:
* expensive virtual method call which prevents inlining
* palette lookup for every pixel
* branch on whether palette animation is enabled on every pixel

Regenerate project files.

8 files changed, 53 insertions, 9 deletions

diff --git a/src/blitter/32bpp_anim.cpp b/src/blitter/32bpp_anim.cpp
index 98ae22b00..27b1fbd5b 100644
--- a/src/blitter/32bpp_anim.cpp
+++ b/src/blitter/32bpp_anim.cpp
@@ -12,6 +12,7 @@
 #include "../stdafx.h"
 #include "../video/video_driver.hpp"
 #include "32bpp_anim.hpp"
+#include "common.hpp"
 
 #include "../table/sprites.h"
 
@@ -321,6 +322,24 @@ void Blitter_32bppAnim::SetPixel(void *video, int x, int y, uint8 colour)
 	this->anim_buf[this->ScreenToAnimOffset((uint32 *)video) + x + y * this->anim_buf_pitch] = colour | (DEFAULT_BRIGHTNESS << 8);
 }
 
+void Blitter_32bppAnim::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash)
+{
+	const Colour c = LookupColourInPalette(colour);
+
+	if (_screen_disable_anim)  {
+		this->DrawLineGeneric(x, y, x2, y2, screen_width, screen_height, width, dash, [&](int x, int y) {
+			*((Colour *)video + x + y * _screen.pitch) = c;
+		});
+	} else {
+		uint16 * const offset_anim_buf = this->anim_buf + this->ScreenToAnimOffset((uint32 *)video);
+		const uint16 anim_colour = colour | (DEFAULT_BRIGHTNESS << 8);
+		this->DrawLineGeneric(x, y, x2, y2, screen_width, screen_height, width, dash, [&](int x, int y) {
+			*((Colour *)video + x + y * _screen.pitch) = c;
+			offset_anim_buf[x + y * this->anim_buf_pitch] = anim_colour;
+		});
+	}
+}
+
 void Blitter_32bppAnim::DrawRect(void *video, int width, int height, uint8 colour)
 {
 	if (_screen_disable_anim) {
diff --git a/src/blitter/32bpp_anim.hpp b/src/blitter/32bpp_anim.hpp
index da33ec95b..ecf6dcfca 100644
--- a/src/blitter/32bpp_anim.hpp
+++ b/src/blitter/32bpp_anim.hpp
@@ -40,6 +40,7 @@ public:
 	/* virtual */ void Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom);
 	/* virtual */ void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal);
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
+	/* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash);
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
diff --git a/src/blitter/32bpp_base.cpp b/src/blitter/32bpp_base.cpp
index c396e4541..b2e66b0be 100644
--- a/src/blitter/32bpp_base.cpp
+++ b/src/blitter/32bpp_base.cpp
@@ -11,6 +11,7 @@
 
 #include "../stdafx.h"
 #include "32bpp_base.hpp"
+#include "common.hpp"
 
 #include "../safeguards.h"
 
@@ -24,6 +25,14 @@ void Blitter_32bppBase::SetPixel(void *video, int x, int y, uint8 colour)
 	*((Colour *)video + x + y * _screen.pitch) = LookupColourInPalette(colour);
 }
 
+void Blitter_32bppBase::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash)
+{
+	const Colour c = LookupColourInPalette(colour);
+	this->DrawLineGeneric(x, y, x2, y2, screen_width, screen_height, width, dash, [=](int x, int y) {
+		*((Colour *)video + x + y * _screen.pitch) = c;
+	});
+}
+
 void Blitter_32bppBase::DrawRect(void *video, int width, int height, uint8 colour)
 {
 	Colour colour32 = LookupColourInPalette(colour);
diff --git a/src/blitter/32bpp_base.hpp b/src/blitter/32bpp_base.hpp
index 9b7627170..697593da6 100644
--- a/src/blitter/32bpp_base.hpp
+++ b/src/blitter/32bpp_base.hpp
@@ -23,6 +23,7 @@ public:
 	/* virtual */ uint8 GetScreenDepth() { return 32; }
 	/* virtual */ void *MoveTo(void *video, int x, int y);
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
+	/* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash);
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
diff --git a/src/blitter/8bpp_base.cpp b/src/blitter/8bpp_base.cpp
index eab6eaa0d..dccfda3d7 100644
--- a/src/blitter/8bpp_base.cpp
+++ b/src/blitter/8bpp_base.cpp
@@ -12,6 +12,7 @@
 #include "../stdafx.h"
 #include "../gfx_func.h"
 #include "8bpp_base.hpp"
+#include "common.hpp"
 
 #include "../safeguards.h"
 
@@ -35,6 +36,13 @@ void Blitter_8bppBase::SetPixel(void *video, int x, int y, uint8 colour)
 	*((uint8 *)video + x + y * _screen.pitch) = colour;
 }
 
+void Blitter_8bppBase::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash)
+{
+	this->DrawLineGeneric(x, y, x2, y2, screen_width, screen_height, width, dash, [=](int x, int y) {
+		*((uint8 *)video + x + y * _screen.pitch) = colour;
+	});
+}
+
 void Blitter_8bppBase::DrawRect(void *video, int width, int height, uint8 colour)
 {
 	do {
diff --git a/src/blitter/8bpp_base.hpp b/src/blitter/8bpp_base.hpp
index 2dff78499..8f75dda5d 100644
--- a/src/blitter/8bpp_base.hpp
+++ b/src/blitter/8bpp_base.hpp
@@ -21,6 +21,7 @@ public:
 	/* virtual */ void DrawColourMappingRect(void *dst, int width, int height, PaletteID pal);
 	/* virtual */ void *MoveTo(void *video, int x, int y);
 	/* virtual */ void SetPixel(void *video, int x, int y, uint8 colour);
+	/* virtual */ void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash);
 	/* virtual */ void DrawRect(void *video, int width, int height, uint8 colour);
 	/* virtual */ void CopyFromBuffer(void *video, const void *src, int width, int height);
 	/* virtual */ void CopyToBuffer(const void *video, void *dst, int width, int height);
diff --git a/src/blitter/base.hpp b/src/blitter/base.hpp
index a9403b339..388359441 100644
--- a/src/blitter/base.hpp
+++ b/src/blitter/base.hpp
@@ -122,7 +122,7 @@ public:
 	 * @param width Line width.
 	 * @param dash Length of dashes for dashed lines. 0 means solid line.
 	 */
-	virtual void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash = 0);
+	virtual void DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash = 0) = 0;
 
 	/**
 	 * Copy from a buffer to the screen.
@@ -203,6 +203,8 @@ public:
 	virtual void PostResize() { };
 
 	virtual ~Blitter() { }
+
+	template <typename SetPixelT> void DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, int screen_height, int width, int dash, SetPixelT set_pixel);
 };
 
 #endif /* BLITTER_BASE_HPP */
diff --git a/src/blitter/base.cpp b/src/blitter/common.hpp
index e83df2e71..0e255ca9a 100644
--- a/src/blitter/base.cpp
+++ b/src/blitter/common.hpp
@@ -7,15 +7,16 @@
  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
  */
 
-/** @file base.cpp Implementation of the base for all blitters. */
+/** @file common.hpp Common functionality for all blitter implementations. */
+
+#ifndef BLITTER_COMMON_HPP
+#define BLITTER_COMMON_HPP
 
-#include "../stdafx.h"
 #include "base.hpp"
 #include "../core/math_func.hpp"
 
-#include "../safeguards.h"
-
-void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width, int dash)
+template <typename SetPixelT>
+void Blitter::DrawLineGeneric(int x, int y, int x2, int y2, int screen_width, int screen_height, int width, int dash, SetPixelT set_pixel)
 {
 	int dy;
 	int dx;
@@ -40,7 +41,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 
 	if (dx == 0 && dy == 0) {
 		/* The algorithm below cannot handle this special case; make it work at least for line width 1 */
-		if (x >= 0 && x < screen_width && y >= 0 && y < screen_height) this->SetPixel(video, x, y, colour);
+		if (x >= 0 && x < screen_width && y >= 0 && y < screen_height) set_pixel(x, y);
 		return;
 	}
 
@@ -83,7 +84,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		while (x != x2) {
 			if (dash_count < dash && x >= 0 && x < screen_width) {
 				for (int y = y_low; y != y_high; y += stepy) {
-					if (y >= 0 && y < screen_height) this->SetPixel(video, x, y, colour);
+					if (y >= 0 && y < screen_height) set_pixel(x, y);
 				}
 			}
 			if (frac_low >= 0) {
@@ -118,7 +119,7 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		while (y != y2) {
 			if (dash_count < dash && y >= 0 && y < screen_height) {
 				for (int x = x_low; x != x_high; x += stepx) {
-					if (x >= 0 && x < screen_width) this->SetPixel(video, x, y, colour);
+					if (x >= 0 && x < screen_width) set_pixel(x, y);
 				}
 			}
 			if (frac_low >= 0) {
@@ -136,3 +137,5 @@ void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_wid
 		}
 	}
 }
+
+#endif /* BLITTER_COMMON_HPP */