Split glyph surface creation and pixel upload

When DirectX-SDL2 loses its device, it doesn't lose its textures,
just their contents, so we shouldn't remake the textures when we
regenerate the glyphs (that's coming next commit).

src/Backends/Rendering.h

@@ -25,8 +25,9 @@ void Backend_UnlockSurface(Backend_Surface *surface);
 void Backend_Blit(Backend_Surface *source_surface, const RECT *rect, Backend_Surface *destination_surface, long x, long y, BOOL colour_key);
 void Backend_ColourFill(Backend_Surface *surface, const RECT *rect, unsigned char red, unsigned char green, unsigned char blue);
 BOOL Backend_SupportsSubpixelGlyphs(void);
-Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned char pixel_mode);
+Backend_Glyph* Backend_CreateGlyph(unsigned int width, unsigned int height, unsigned char pixel_mode);
-void Backend_UnloadGlyph(Backend_Glyph *glyph);
+void Backend_FreeGlyph(Backend_Glyph *glyph);
+void Backend_LoadGlyphPixels(Backend_Glyph *glyph, const unsigned char *pixels, int pitch);
 void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours);
 void Backend_HandleDeviceLoss(void);
 void Backend_HandleWindowResize(void);

src/Backends/Rendering/OpenGL3.cpp

@@ -628,37 +628,73 @@ BOOL Backend_SupportsSubpixelGlyphs(void)
 	return TRUE;
 }
 
-Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned char pixel_mode)
+Backend_Glyph* Backend_CreateGlyph(unsigned int width, unsigned int height, unsigned char pixel_mode)
 {
 	Backend_Glyph *glyph = (Backend_Glyph*)malloc(sizeof(Backend_Glyph));
 
 	if (glyph == NULL)
 		return NULL;
 
-	const unsigned int destination_pitch = (width + 3) & ~3;	// Round up to the nearest 4 (OpenGL needs this)
+	GLint previously_bound_texture;
+	glGetIntegerv(GL_TEXTURE_BINDING_2D, &previously_bound_texture);
 
-	unsigned char *buffer = (unsigned char*)malloc(destination_pitch * height);
+	glGenTextures(1, &glyph->texture_id);
+	glBindTexture(GL_TEXTURE_2D, glyph->texture_id);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
 
-	switch (pixel_mode)
+	glyph->width = width;
+	glyph->height = height;
+	glyph->pixel_mode = pixel_mode;
+
+	glBindTexture(GL_TEXTURE_2D, previously_bound_texture);
+
+	return glyph;
+}
+
+void Backend_FreeGlyph(Backend_Glyph *glyph)
+{
+	if (glyph == NULL)
+		return;
+
+	glDeleteTextures(1, &glyph->texture_id);
+	free(glyph);
+}
+
+void Backend_LoadGlyphPixels(Backend_Glyph *glyph, const unsigned char *pixels, int pitch)
+{
+	if (glyph == NULL)
+		return;
+
+	const unsigned int width_in_bytes = (glyph->pixel_mode == FONT_PIXEL_MODE_LCD ? glyph->width * 3 : glyph->width);
+
+	const unsigned int destination_pitch = (width_in_bytes + 3) & ~3;	// Round up to the nearest 4 (OpenGL needs this)
+
+	unsigned char *buffer = (unsigned char*)malloc(destination_pitch * glyph->height);
+
+	switch (glyph->pixel_mode)
 	{
 		case FONT_PIXEL_MODE_LCD:
 		case FONT_PIXEL_MODE_GRAY:
-			for (unsigned int y = 0; y < height; ++y)
+			for (unsigned int y = 0; y < glyph->height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = buffer + y * destination_pitch;
-				memcpy(destination_pointer, source_pointer, width);
+				memcpy(destination_pointer, source_pointer, width_in_bytes);
 			}
 
 			break;
 
 		case FONT_PIXEL_MODE_MONO:
-			for (unsigned int y = 0; y < height; ++y)
+			for (unsigned int y = 0; y < glyph->height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = buffer + y * destination_pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (unsigned int x = 0; x < width_in_bytes; ++x)
 					*destination_pointer++ = (*source_pointer++ ? 0xFF : 0);
 			}
 
@@ -668,36 +704,15 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 	GLint previously_bound_texture;
 	glGetIntegerv(GL_TEXTURE_BINDING_2D, &previously_bound_texture);
 
-	glGenTextures(1, &glyph->texture_id);
 	glBindTexture(GL_TEXTURE_2D, glyph->texture_id);
-	if (pixel_mode == FONT_PIXEL_MODE_LCD)
+	if (glyph->pixel_mode == FONT_PIXEL_MODE_LCD)
-		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width / 3, height, 0, GL_RGB, GL_UNSIGNED_BYTE, buffer);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, glyph->width, glyph->height, 0, GL_RGB, GL_UNSIGNED_BYTE, buffer);
 	else
-		glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, width, height, 0, GL_RED, GL_UNSIGNED_BYTE, buffer);
+		glTexImage2D(GL_TEXTURE_2D, 0, GL_R8, glyph->width, glyph->height, 0, GL_RED, GL_UNSIGNED_BYTE, buffer);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
-
-	glyph->width = (pixel_mode == FONT_PIXEL_MODE_LCD ? width / 3 : width);
-	glyph->height = height;
-	glyph->pixel_mode = pixel_mode;
 
 	free(buffer);
 
 	glBindTexture(GL_TEXTURE_2D, previously_bound_texture);
-
-	return glyph;
-}
-
-void Backend_UnloadGlyph(Backend_Glyph *glyph)
-{
-	if (glyph == NULL)
-		return;
-
-	glDeleteTextures(1, &glyph->texture_id);
-	free(glyph);
 }
 
 void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)

src/Backends/Rendering/SDLSurface.cpp

@@ -15,6 +15,7 @@ typedef struct Backend_Surface
 typedef struct Backend_Glyph
 {
 	SDL_Surface *sdlsurface;
+	unsigned char pixel_mode;
 } Backend_Glyph;
 
 static SDL_Window *window;
@@ -142,7 +143,7 @@ BOOL Backend_SupportsSubpixelGlyphs(void)
 	return FALSE;	// SDL_Surfaces don't have per-component alpha
 }
 
-Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned char pixel_mode)
+Backend_Glyph* Backend_CreateGlyph(unsigned int width, unsigned int height, unsigned char pixel_mode)
 {
 	Backend_Glyph *glyph = (Backend_Glyph*)malloc(sizeof(Backend_Glyph));
 
@@ -157,17 +158,36 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 		return NULL;
 	}
 
-	switch (pixel_mode)
+	glyph->pixel_mode = pixel_mode;
+
+	return glyph;
+}
+
+void Backend_FreeGlyph(Backend_Glyph *glyph)
+{
+	if (glyph == NULL)
+		return;
+
+	SDL_FreeSurface(glyph->sdlsurface);
+	free(glyph);
+}
+
+void Backend_LoadGlyphPixels(Backend_Glyph *glyph, const unsigned char *pixels, int pitch)
+{
+	if (glyph == NULL)
+		return;
+
+	switch (glyph->pixel_mode)
 	{
 		// FONT_PIXEL_MODE_LCD is unsupported
 
 		case FONT_PIXEL_MODE_GRAY:
-			for (unsigned int y = 0; y < height; ++y)
+			for (int y = 0; y < glyph->sdlsurface->h; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = (unsigned char*)glyph->sdlsurface->pixels + y * glyph->sdlsurface->pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (int x = 0; x < glyph->sdlsurface->w; ++x)
 				{
 					*destination_pointer++ = 0xFF;
 					*destination_pointer++ = 0xFF;
@@ -179,12 +199,12 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 			break;
 
 		case FONT_PIXEL_MODE_MONO:
-			for (unsigned int y = 0; y < height; ++y)
+			for (int y = 0; y < glyph->sdlsurface->h; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = (unsigned char*)glyph->sdlsurface->pixels + y * glyph->sdlsurface->pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (int x = 0; x < glyph->sdlsurface->w; ++x)
 				{
 					*destination_pointer++ = 0xFF;
 					*destination_pointer++ = 0xFF;
@@ -195,17 +215,6 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 
 			break;
 	}
-
-	return glyph;
-}
-
-void Backend_UnloadGlyph(Backend_Glyph *glyph)
-{
-	if (glyph == NULL)
-		return;
-
-	SDL_FreeSurface(glyph->sdlsurface);
-	free(glyph);
 }
 
 void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)

src/Backends/Rendering/SDLTexture.cpp

@@ -24,6 +24,7 @@ typedef struct Backend_Surface
 typedef struct Backend_Glyph
 {
 	Backend_Surface *surface;
+	unsigned char pixel_mode;
 } Backend_Glyph;
 
 static SDL_Renderer *renderer;
@@ -150,10 +151,10 @@ void Backend_UnlockSurface(Backend_Surface *surface)
 		const unsigned char *src_pixel = surface->pixels;
 
 		// Convert the SDL_Surface's colour-keyed pixels to RGBA32
-		for (int y = 0; y < surface->height; ++y)
+		for (unsigned int y = 0; y < surface->height; ++y)
 		{
 
-			for (int x = 0; x < surface->width; ++x)
+			for (unsigned int x = 0; x < surface->width; ++x)
 			{
 				*buffer_pointer++ = src_pixel[0];
 				*buffer_pointer++ = src_pixel[1];
@@ -218,7 +219,7 @@ BOOL Backend_SupportsSubpixelGlyphs(void)
 	return FALSE;	// SDL_Textures don't have per-component alpha
 }
 
-Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned char pixel_mode)
+Backend_Glyph* Backend_CreateGlyph(unsigned int width, unsigned int height, unsigned char pixel_mode)
 {
 	Backend_Glyph *glyph = (Backend_Glyph*)malloc(sizeof(Backend_Glyph));
 
@@ -233,20 +234,39 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 		return NULL;
 	}
 
+	glyph->pixel_mode = pixel_mode;
+
+	return glyph;
+}
+
+void Backend_FreeGlyph(Backend_Glyph *glyph)
+{
+	if (glyph == NULL)
+		return;
+
+	Backend_FreeSurface(glyph->surface);
+	free(glyph);
+}
+
+void Backend_LoadGlyphPixels(Backend_Glyph *glyph, const unsigned char *pixels, int pitch)
+{
+	if (glyph == NULL)
+		return;
+
 	unsigned int surface_pitch;
 	unsigned char *surface_pixels = Backend_LockSurface(glyph->surface, &surface_pitch);
 
-	switch (pixel_mode)
+	switch (glyph->pixel_mode)
 	{
 		// FONT_PIXEL_MODE_LCD is unsupported
 
 		case FONT_PIXEL_MODE_GRAY:
-			for (unsigned int y = 0; y < height; ++y)
+			for (unsigned int y = 0; y < glyph->surface->height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = surface_pixels + y * surface_pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (unsigned int x = 0; x < glyph->surface->width; ++x)
 				{
 					*destination_pointer++ = 0xFF;
 					*destination_pointer++ = 0xFF;
@@ -258,12 +278,12 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 			break;
 
 		case FONT_PIXEL_MODE_MONO:
-			for (unsigned int y = 0; y < height; ++y)
+			for (unsigned int y = 0; y < glyph->surface->height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 				unsigned char *destination_pointer = surface_pixels + y * surface_pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (unsigned int x = 0; x < glyph->surface->width; ++x)
 				{
 					*destination_pointer++ = 0xFF;
 					*destination_pointer++ = 0xFF;
@@ -276,17 +296,6 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 	}
 
 	Backend_UnlockSurface(glyph->surface);
-
-	return glyph;
-}
-
-void Backend_UnloadGlyph(Backend_Glyph *glyph)
-{
-	if (glyph == NULL)
-		return;
-
-	Backend_FreeSurface(glyph->surface);
-	free(glyph);
 }
 
 void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)

src/Backends/Rendering/Software.cpp

@@ -260,33 +260,56 @@ BOOL Backend_SupportsSubpixelGlyphs(void)
 	return TRUE;	// It's a software renderer, baby
 }
 
-Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width, unsigned int height, int pitch, unsigned char pixel_mode)
+Backend_Glyph* Backend_CreateGlyph(unsigned int width, unsigned int height, unsigned char pixel_mode)
 {
 	Backend_Glyph *glyph = (Backend_Glyph*)malloc(sizeof(Backend_Glyph));
 
 	if (glyph == NULL)
 		return NULL;
 
-	switch (pixel_mode)
+	glyph->pixels = malloc(width * height * (pixel_mode == FONT_PIXEL_MODE_MONO ? sizeof(unsigned char) : sizeof(float)));
+
+	if (glyph->pixels == NULL)
+	{
+		free(glyph);
+		return NULL;
+	}
+
+	glyph->width = width;
+	glyph->height = height;
+	glyph->pixel_mode = pixel_mode;
+
+	return glyph;
+}
+
+void Backend_FreeGlyph(Backend_Glyph *glyph)
+{
+	if (glyph == NULL)
+		return;
+
+	free(glyph->pixels);
+	free(glyph);
+}
+
+void Backend_LoadGlyphPixels(Backend_Glyph *glyph, const unsigned char *pixels, int pitch)
+{
+	if (glyph == NULL)
+		return;
+
+	const unsigned int width_in_bytes = (glyph->pixel_mode == FONT_PIXEL_MODE_LCD ? glyph->width * 3 : glyph->width);
+
+	switch (glyph->pixel_mode)
 	{
 		case FONT_PIXEL_MODE_LCD:
 		case FONT_PIXEL_MODE_GRAY:
 		{
-			glyph->pixels = malloc(width * height * sizeof(float));
-
-			if (glyph->pixels == NULL)
-			{
-				free(glyph);
-				return NULL;
-			}
-
 			float *destination_pointer = (float*)glyph->pixels;
 
-			for (unsigned int y = 0; y < height; ++y)
+			for (unsigned int y = 0; y < glyph->height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
 
-				for (unsigned int x = 0; x < width; ++x)
+				for (unsigned int x = 0; x < width_in_bytes; ++x)
 					*destination_pointer++ = *source_pointer++ / 255.0f;
 			}
 
@@ -295,40 +318,17 @@ Backend_Glyph* Backend_LoadGlyph(const unsigned char *pixels, unsigned int width
 
 		case FONT_PIXEL_MODE_MONO:
 		{
-			glyph->pixels = malloc(width * height);
+			for (unsigned int y = 0; y < glyph->height; ++y)
-
-			if (glyph->pixels == NULL)
-			{
-				free(glyph);
-				return NULL;
-			}
-
-			for (unsigned int y = 0; y < height; ++y)
 			{
 				const unsigned char *source_pointer = pixels + y * pitch;
-				unsigned char *destination_pointer = (unsigned char*)glyph->pixels + y * width;
+				unsigned char *destination_pointer = (unsigned char*)glyph->pixels + y * width_in_bytes;
 
-				memcpy(destination_pointer, source_pointer, width);
+				memcpy(destination_pointer, source_pointer, width_in_bytes);
 			}
 
 			break;
 		}
 	}
-
-	glyph->width = (pixel_mode == FONT_PIXEL_MODE_LCD ? width / 3 : width);
-	glyph->height = height;
-	glyph->pixel_mode = pixel_mode;
-
-	return glyph;
-}
-
-void Backend_UnloadGlyph(Backend_Glyph *glyph)
-{
-	if (glyph == NULL)
-		return;
-
-	free(glyph->pixels);
-	free(glyph);
 }
 
 void Backend_DrawGlyph(Backend_Surface *surface, Backend_Glyph *glyph, long x, long y, const unsigned char *colours)

src/Font.cpp

@@ -1027,7 +1027,8 @@ static CachedGlyph* GetGlyphCached(FontObject *font_object, unsigned long unicod
 				break;
 		}
 
-		glyph->backend = Backend_LoadGlyph(bitmap.buffer, bitmap.width, bitmap.rows, bitmap.pitch, pixel_mode);
+		glyph->backend = Backend_CreateGlyph((pixel_mode == FT_PIXEL_MODE_LCD ? bitmap.width / 3 : bitmap.width), bitmap.rows, pixel_mode);
+		Backend_LoadGlyphPixels(glyph->backend, bitmap.buffer, bitmap.pitch);
 
 		FT_Bitmap_Done(font_object->library, &bitmap);
 	}
@@ -1042,7 +1043,7 @@ static void UnloadCachedGlyphs(FontObject *font_object)
 	{
 		CachedGlyph *next_glyph = glyph->next;
 
-		Backend_UnloadGlyph(glyph->backend);
+		Backend_FreeGlyph(glyph->backend);
 		free(glyph);
 
 		glyph = next_glyph;