love2d.love/src/modules/graphics/Video.cpp

/**
 * Copyright (c) 2006-2024 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 "Video.h"

// LOVE
#include "Shader.h"
#include "Graphics.h"

namespace love
{
namespace graphics
{

love::Type Video::type("Video", &Drawable::type);

Video::Video(Graphics *gfx, love::video::VideoStream *stream, float dpiscale)
	: stream(stream)
	, width(stream->getWidth() / dpiscale)
	, height(stream->getHeight() / dpiscale)
	, samplerState()
{
	const SamplerState &defaultSampler = gfx->getDefaultSamplerState();
	samplerState.minFilter = defaultSampler.minFilter;
	samplerState.magFilter = defaultSampler.magFilter;
	samplerState.wrapU = defaultSampler.wrapU;
	samplerState.wrapV = defaultSampler.wrapV;
	samplerState.maxAnisotropy = defaultSampler.maxAnisotropy;

	stream->fillBackBuffer();

	for (int i = 0; i < 4; i++)
		vertices[i].color = Color32(255, 255, 255, 255);

	// Vertices are ordered for use with triangle strips:
	// 0---2
	// | / |
	// 1---3
	vertices[0].x = 0.0f;
	vertices[0].y = 0.0f;
	vertices[1].x = 0.0f;
	vertices[1].y = (float) height;
	vertices[2].x = (float) width;
	vertices[2].y = 0.0f;
	vertices[3].x = (float) width;
	vertices[3].y = (float) height;

	vertices[0].s = 0.0f;
	vertices[0].t = 0.0f;
	vertices[1].s = 0.0f;
	vertices[1].t = 1.0f;
	vertices[2].s = 1.0f;
	vertices[2].t = 0.0f;
	vertices[3].s = 1.0f;
	vertices[3].t = 1.0f;

	// Create the textures using the initial frame data.
	auto frame = (const love::video::VideoStream::Frame*) stream->getFrontBuffer();

	int widths[3]  = {frame->yw, frame->cw, frame->cw};
	int heights[3] = {frame->yh, frame->ch, frame->ch};

	const unsigned char *data[3] = {frame->yplane, frame->cbplane, frame->crplane};

	Texture::Settings settings;

	for (int i = 0; i < 3; i++)
	{
		settings.width = widths[i];
		settings.height = heights[i];
		settings.format = PIXELFORMAT_R8_UNORM;
		Texture *tex = gfx->newTexture(settings, nullptr);

		tex->setSamplerState(samplerState);

		size_t bpp = getPixelFormatBlockSize(PIXELFORMAT_R8_UNORM);
		size_t size = bpp * widths[i] * heights[i];

		Rect rect = {0, 0, widths[i], heights[i]};
		tex->replacePixels(data[i], size, 0, 0, rect, false);

		textures[i].set(tex, Acquire::NORETAIN);
	}
}

Video::~Video()
{
	if (source)
		source->stop();
}

love::video::VideoStream *Video::getStream()
{
	return stream;
}

void Video::draw(Graphics *gfx, const Matrix4 &m)
{
	update();

	// setVideoTextures may call flushBatchedDraws before setting the textures, so
	// we can't call it after requestBatchedDraw.
	auto shader = Shader::current;
	if (Shader::isDefaultActive())
		shader = Shader::standardShaders[Shader::STANDARD_VIDEO];

	if (shader != nullptr)
		shader->setVideoTextures(textures[0], textures[1], textures[2]);

	const Matrix4 &tm = gfx->getTransform();
	bool is2D = tm.isAffine2DTransform();

	Matrix4 t(tm, m);

	Graphics::BatchedDrawCommand cmd;
	cmd.formats[0] = getSinglePositionFormat(is2D);
	cmd.formats[1] = CommonFormat::STf_RGBAub;
	cmd.indexMode = TRIANGLEINDEX_QUADS;
	cmd.vertexCount = 4;
	cmd.standardShaderType = Shader::STANDARD_VIDEO;

	Graphics::BatchedVertexData data = gfx->requestBatchedDraw(cmd);

	if (is2D)
		t.transformXY((Vector2 *) data.stream[0], vertices, 4);
	else
		t.transformXY0((Vector3 *) data.stream[0], vertices, 4);

	STf_RGBAub *verts = (STf_RGBAub *) data.stream[1];

	Color32 c = toColor32(gfx->getColor());

	for (int i = 0; i < 4; i++)
	{
		verts[i].s = vertices[i].s;
		verts[i].t = vertices[i].t;
		verts[i].color = c;
	}

	gfx->flushBatchedDraws();
}

void Video::update()
{
	bool bufferschanged = stream->swapBuffers();
	stream->fillBackBuffer();

	if (bufferschanged)
	{
		auto frame = (const love::video::VideoStream::Frame*) stream->getFrontBuffer();

		int widths[3]  = {frame->yw, frame->cw, frame->cw};
		int heights[3] = {frame->yh, frame->ch, frame->ch};

		const unsigned char *data[3] = {frame->yplane, frame->cbplane, frame->crplane};

		for (int i = 0; i < 3; i++)
		{
			size_t bpp = getPixelFormatBlockSize(PIXELFORMAT_R8_UNORM);
			size_t size = bpp * widths[i] * heights[i];

			Rect rect = {0, 0, widths[i], heights[i]};
			textures[i]->replacePixels(data[i], size, 0, 0, rect, false);
		}
	}
}

love::audio::Source *Video::getSource()
{
	return source;
}

void Video::setSource(love::audio::Source *source)
{
	this->source = source;
}

int Video::getWidth() const
{
	return width;
}

int Video::getHeight() const
{
	return height;
}

int Video::getPixelWidth() const
{
	return stream->getWidth();
}

int Video::getPixelHeight() const
{
	return stream->getHeight();
}

void Video::setSamplerState(const SamplerState &s)
{
	samplerState.minFilter = s.minFilter;
	samplerState.magFilter = s.magFilter;
	samplerState.wrapU = s.wrapU;
	samplerState.wrapV = s.wrapV;
	samplerState.maxAnisotropy = s.maxAnisotropy;

	for (const auto &texture : textures)
		texture->setSamplerState(samplerState);
}

const SamplerState &Video::getSamplerState() const
{
	return samplerState;
}

} // graphics
} // love