Add optimized method to render text.

Retains results of text rendering in a texture, and ignores (caches) identical strings being set. Initial uses gives approx 10% better FPS on opening view on Rush.
Warzone2100 · Mar 29, 2017 · a709209 · a709209
1 parent 486dd8e
commit a709209
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Showing 3 changed files with 107 additions and 11 deletions.
diff --git a/lib/ivis_opengl/textdraw.cpp b/lib/ivis_opengl/textdraw.cpp
@@ -186,6 +186,8 @@ struct FTFace
 		return m_face;
 	}
 
+	FT_Face &face() { return m_face; }
+
 	hb_font_t *m_font;
 
 private:
@@ -422,8 +424,8 @@ static FTFace &getFTFace(iV_fonts FontID)
 	}
 }
 
-static GLuint textureID;
-static GLuint pbo;
+static GLuint textureID = 0;
+static GLuint pbo = 0;
 
 void iV_TextInit()
 {
@@ -723,3 +725,64 @@ void iV_DrawTextF(float x, float y, const char *format, ...)
 	va_end(ap);
 }
 #endif
+
+void WzText::setText(const std::string &string, iV_fonts fontID)
+{
+	if (mText == string && fontID == mFontID)
+	{
+		return; // cached
+	}
+	mFontID = fontID;
+	mText = string;
+	if (texture == 0)
+	{
+		pie_SetTexturePage(TEXPAGE_EXTERN);
+		glGenTextures(1, &texture);
+		glBindTexture(GL_TEXTURE_2D, texture);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	}
+	TextRun tr(string, "en", HB_SCRIPT_COMMON, HB_DIRECTION_LTR);
+	std::unique_ptr<unsigned char[]> data;
+	FTFace &face = getFTFace(fontID);
+	FT_Face &type = face.face();
+	std::tie(data, dimensions.x, dimensions.y, offsets.x, offsets.y) = getShaper().drawText(tr, face);
+	if (dimensions.x > 0 && dimensions.y > 0)
+	{
+		pie_SetTexturePage(TEXPAGE_EXTERN);
+		glBindTexture(GL_TEXTURE_2D, texture);
+		glBindBuffer(GL_PIXEL_UNPACK_BUFFER, pbo);
+		glBufferData(GL_PIXEL_UNPACK_BUFFER, 4 * dimensions.x * dimensions.y, data.get(), GL_STREAM_DRAW);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, dimensions.x, dimensions.y, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+		glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
+
+		mAboveBase = -(type->size->metrics.ascender >> 6);
+		mLineSize = (type->size->metrics.ascender - type->size->metrics.descender) >> 6;
+		mBelowBase = type->size->metrics.descender >> 6;
+	}
+	glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+WzText::WzText(const std::string &string, iV_fonts fontID)
+{
+	setText(string, fontID);
+}
+
+WzText::~WzText()
+{
+	glDeleteTextures(1, &texture); // ok to call with texture ID zero
+}
+
+void WzText::render(Vector2i position, PIELIGHT colour, float rotation)
+{
+	ASSERT(texture != 0, "Text not initialized before rendering");
+	if (rotation != 0.f)
+	{
+		rotation = 180. - rotation;
+	}
+	glDisable(GL_CULL_FACE);
+	iV_DrawImage(texture, position, offsets, dimensions, rotation, REND_TEXT, colour);
+	glEnable(GL_CULL_FACE);
+}
diff --git a/lib/ivis_opengl/textdraw.h b/lib/ivis_opengl/textdraw.h
@@ -34,6 +34,32 @@ enum iV_fonts
 	font_count
 };
 
+class WzText
+{
+public:
+	WzText() {}
+	WzText(const std::string &text, iV_fonts fontID);
+	void setText(const std::string &text, iV_fonts fontID);
+	~WzText();
+	int width() { return dimensions.x; }
+	int height() { return dimensions.y; }
+	void render(Vector2i position, PIELIGHT colour, float rotation = 0.0f);
+	void render(int x, int y, PIELIGHT colour, float rotation = 0.0f) { render(Vector2i{x,y}, colour, rotation); }
+	int aboveBase() { return mAboveBase; }
+	int belowBase() { return mBelowBase; }
+	int lineSize() { return mLineSize; }
+
+private:
+	iV_fonts mFontID = font_count;
+	std::string mText;
+	GLuint texture = 0;
+	int mAboveBase = 0;
+	int mBelowBase = 0;
+	int mLineSize = 0;
+	Vector2i offsets;
+	Vector2i dimensions;
+};
+
 void iV_TextInit();
 void iV_TextShutdown();
 void iV_font(const char *fontName, const char *fontFace, const char *fontFaceBold);

diff --git a/src/display3d.cpp b/src/display3d.cpp
@@ -132,6 +132,11 @@ static void NetworkDisplayPlainForm(WIDGET *psWidget, UDWORD xOffset, UDWORD yOf
 static void NetworkDisplayImage(WIDGET *psWidget, UDWORD xOffset, UDWORD yOffset);
 extern bool writeGameInfo(const char *pFileName); // Used to help debug issues when we have fatal errors & crash handler testing.
 
+static WzText txtLevelName;
+static WzText txtDebugStatus;
+static WzText txtCurrentTime;
+static WzText txtShowFPS;
+
 /********************  Variables  ********************/
 // Should be cleaned up properly and be put in structures.
 
@@ -803,13 +808,12 @@ void draw3DScene(void)
 	}
 	if (showFPS)
 	{
-		unsigned int width, height;
 		const char *fps;
 		sasprintf((char **)&fps, "FPS: %d", frameRate());
-		width = iV_GetTextWidth(fps, font_regular) + 10;
-		height = iV_GetTextHeight(fps, font_regular);
-
-		iV_DrawText(fps, pie_GetVideoBufferWidth() - width, pie_GetVideoBufferHeight() - height, font_regular);
+		txtShowFPS.setText(fps, font_regular);
+		const unsigned width = txtShowFPS.width() + 10;
+		const unsigned height = txtShowFPS.height();
+		txtShowFPS.render(pie_GetVideoBufferWidth() - width, pie_GetVideoBufferHeight() - height, WZCOL_TEXT_BRIGHT);
 	}
 	if (showORDERS)
 	{
@@ -823,14 +827,14 @@ void draw3DScene(void)
 	if (getWidgetsStatus() && !gamePaused())
 	{
 		char buildInfo[255];
-		iV_SetTextColour(WZCOL_TEXT_MEDIUM);
-		iV_DrawText(getLevelName(), RET_X + 134, 410 + E_H, font_small);
 		getAsciiTime(buildInfo, graphicsTime);
-		iV_DrawText(buildInfo, RET_X + 134, 422 + E_H, font_small);
+		txtLevelName.render(RET_X + 134, 410 + E_H, WZCOL_TEXT_MEDIUM);
 		if (getDebugMappingStatus())
 		{
-			iV_DrawText("DEBUG ", RET_X + 134, 436 + E_H, font_small);
+			txtDebugStatus.render(RET_X + 134, 436 + E_H, WZCOL_TEXT_MEDIUM);
 		}
+		txtCurrentTime.setText(buildInfo, font_small);
+		txtCurrentTime.render(RET_X + 134, 422 + E_H, WZCOL_TEXT_MEDIUM);
 	}
 
 	while (player.r.y > DEG(360))
@@ -1124,6 +1128,9 @@ bool init3DView(void)
 		return false;
 	}
 
+	txtLevelName.setText(getLevelName(), font_small);
+	txtDebugStatus.setText("DEBUG ", font_small);
+
 	return true;
 }