love/src/modules/graphics/Canvas.cpp

/**
 * Copyright (c) 2006-2020 LOVE Development Team
 *
 * This software is provided 'as-is', without any express or implied
 * warranty.  In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software. If you use this software
 *    in a product, an acknowledgment in the product documentation would be
 *    appreciated but is not required.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 **/

#include "Canvas.h"
#include "Graphics.h"

namespace love
{
namespace graphics
{

love::Type Canvas::type("Canvas", &Texture::type);

Canvas::Canvas(const Settings &settings)
	: Texture(settings.type)
{
	this->settings = settings;

	renderTarget = true;
	sRGB = false;
	requestedMSAA = settings.msaa;

	width = settings.width;
	height = settings.height;
	pixelWidth = (int) ((width * settings.dpiScale) + 0.5);
	pixelHeight = (int) ((height * settings.dpiScale) + 0.5);

	format = settings.format;

	if (texType == TEXTURE_VOLUME)
		depth = settings.layers;
	else if (texType == TEXTURE_2D_ARRAY)
		layers = settings.layers;

	if (width <= 0 || height <= 0 || layers <= 0)
		throw love::Exception("Canvas dimensions must be greater than 0.");

	if (texType != TEXTURE_2D && settings.msaa > 1)
		throw love::Exception("MSAA is only supported for Canvases with the 2D texture type.");

	if (settings.readable.hasValue)
		readable = settings.readable.value;
	else
		readable = !isPixelFormatDepthStencil(format);

	if (readable && isPixelFormatDepthStencil(format) && settings.msaa > 1)
		throw love::Exception("Readable depth/stencil Canvases with MSAA are not currently supported.");

	if ((!readable || settings.msaa > 1) && settings.mipmaps != MIPMAPS_NONE)
		throw love::Exception("Non-readable and MSAA textures cannot have mipmaps.");

	if (settings.mipmaps != MIPMAPS_NONE)
		mipmapCount = getTotalMipmapCount(pixelWidth, pixelHeight, depth);

	auto gfx = Module::getInstance<Graphics>(Module::M_GRAPHICS);
	const Graphics::Capabilities &caps = gfx->getCapabilities();

	if (!gfx->isPixelFormatSupported(format, renderTarget, readable, sRGB))
	{
		const char *fstr = "rgba8";
		const char *readablestr = "";
		if (readable != !isPixelFormatDepthStencil(format))
			readablestr = readable ? " readable" : " non-readable";
		love::getConstant(format, fstr);
		throw love::Exception("The %s%s canvas format is not supported by your graphics drivers.", fstr, readablestr);
	}

	if (getRequestedMSAA() > 1 && texType != TEXTURE_2D)
		throw love::Exception("MSAA is only supported for 2D texture types.");

	if (!readable && texType != TEXTURE_2D)
		throw love::Exception("Non-readable pixel formats are only supported for 2D texture types.");

	if (!caps.textureTypes[texType])
	{
		const char *textypestr = "unknown";
		Texture::getConstant(texType, textypestr);
		throw love::Exception("%s textures are not supported on this system!", textypestr);
	}

	validateDimensions(true);
}

Canvas::~Canvas()
{
}

Texture::MipmapsMode Canvas::getMipmapsMode() const
{
	return settings.mipmaps;
}

bool Canvas::getConstant(const char *in, SettingType &out)
{
	return settingTypes.find(in, out);
}

bool Canvas::getConstant(SettingType in, const char *&out)
{
	return settingTypes.find(in, out);
}

const char *Canvas::getConstant(SettingType in)
{
	const char *name = nullptr;
	getConstant(in, name);
	return name;
}

std::vector<std::string> Canvas::getConstants(SettingType)
{
	return settingTypes.getNames();
}

StringMap<Canvas::SettingType, Canvas::SETTING_MAX_ENUM>::Entry Canvas::settingTypeEntries[] =
{
	// Width / height / layers are currently omittted because they're separate
	// arguments to newCanvas in the wrapper code.
	{ "mipmaps",  SETTING_MIPMAPS   },
	{ "format",   SETTING_FORMAT    },
	{ "type",     SETTING_TYPE      },
	{ "dpiscale", SETTING_DPI_SCALE },
	{ "msaa",     SETTING_MSAA      },
	{ "readable", SETTING_READABLE  },
};

StringMap<Canvas::SettingType, Canvas::SETTING_MAX_ENUM> Canvas::settingTypes(Canvas::settingTypeEntries, sizeof(Canvas::settingTypeEntries));

} // graphics
} // love