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Added support for scissor testing.

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binary1248 2018-06-10 20:57:15 +02:00 committed by Chris Thrasher
parent 08eca7c9a4
commit 5a2f30c5ae
7 changed files with 181 additions and 4 deletions
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16
include/SFML/Graphics/RenderTarget.hpp
View File

@ -153,6 +153,21 @@ public:
////////////////////////////////////////////////////////////
IntRect getViewport(const View& view) const;
////////////////////////////////////////////////////////////
/// \brief Get the scissor rectangle of a view, applied to this render target
///
/// The scissor rectangle is defined in the view as a ratio. This
/// function simply applies this ratio to the current dimensions
/// of the render target to calculate the pixels rectangle
/// that the scissor rectangle actually covers in the target.
///
/// \param view The view for which we want to compute the scissor rectangle
///
/// \return Scissor rectangle, expressed in pixels
///
////////////////////////////////////////////////////////////
IntRect getScissor(const View& view) const;
////////////////////////////////////////////////////////////
/// \brief Convert a point from target coordinates to world
/// coordinates, using the current view
@ -496,6 +511,7 @@ private:
bool enable; //!< Is the cache enabled?
bool glStatesSet{}; //!< Are our internal GL states set yet?
bool viewChanged; //!< Has the current view changed since last draw?
bool scissorEnabled; //!< Is scissor testing enabled?
BlendMode lastBlendMode; //!< Cached blending mode
std::uint64_t lastTextureId; //!< Cached texture
bool texCoordsArrayEnabled; //!< Is GL_TEXTURE_COORD_ARRAY client state enabled?

63
include/SFML/Graphics/View.hpp
View File

@ -119,6 +119,30 @@ public:
////////////////////////////////////////////////////////////
void setViewport(const FloatRect& viewport);
////////////////////////////////////////////////////////////
/// \brief Set the target scissor rectangle
///
/// The scissor rectangle, expressed as a factor (between 0 and 1) of
/// the RenderTarget, specifies the region of the RenderTarget whose
/// pixels are able to be modified by draw or clear operations.
/// Any pixels which lie outside of the scissor rectangle will
/// not be modified by draw or clear operations.
/// For example, a scissor rectangle which only allows modifications
/// to the right side of the target would be defined
/// with View.setScissor(sf::FloatRect({0.5f, 0.f}, {0.5f, 1.f})).
/// By default, a view has a scissor rectangle which allows
/// modifications to the entire target. This is equivalent to
/// disabling the scissor test entirely. Passing the default
/// scissor rectangle to this function will also disable
/// scissor testing.
///
/// \param scissor New scissor rectangle
///
/// \see getScissor
///
////////////////////////////////////////////////////////////
void setScissor(const FloatRect& scissor);
////////////////////////////////////////////////////////////
/// \brief Reset the view to the given rectangle
///
@ -171,6 +195,16 @@ public:
////////////////////////////////////////////////////////////
const FloatRect& getViewport() const;
////////////////////////////////////////////////////////////
/// \brief Get the scissor rectangle of the view
///
/// \return Scissor rectangle, expressed as a factor of the target size
///
/// \see setScissor
///
////////////////////////////////////////////////////////////
const FloatRect& getScissor() const;
////////////////////////////////////////////////////////////
/// \brief Move the view relatively to its current position
///
@ -240,6 +274,7 @@ private:
Vector2f m_size; //!< Size of the view, in scene coordinates
Angle m_rotation; //!< Angle of rotation of the view rectangle
FloatRect m_viewport{{0, 0}, {1, 1}}; //!< Viewport rectangle, expressed as a factor of the render-target's size
FloatRect m_scissor{{0, 0}, {1, 1}}; //!< Scissor rectangle, expressed as a factor of the render-target's size
mutable Transform m_transform; //!< Precomputed projection transform corresponding to the view
mutable Transform m_inverseTransform; //!< Precomputed inverse projection transform corresponding to the view
mutable bool m_transformUpdated{}; //!< Internal state telling if the transform needs to be updated
@ -269,6 +304,34 @@ private:
/// rectangle doesn't have the same size as the viewport, its
/// contents will be stretched to fit in.
///
/// The scissor rectangle allows for specifying regions of the
/// render target to which modifications can be made by draw
/// and clear operations. Only pixels that are within the region
/// will be able to be modified. Pixels outside of the region will
/// not be modified by draw or clear operations.
///
/// Certain effects can be created by either using the viewport or
/// scissor rectangle. While the results appear identical, there
/// can be times where one method should be preferred over the other.
/// Viewport transformations are applied during the vertex processing
/// stage of the graphics pipeline, before the primitives are
/// rasterized into fragments for fragment processing. Since
/// viewport processing has to be performed and cannot be disabled,
/// effects that are performed using the viewport transform are
/// basically free performance-wise. Scissor testing is performed in
/// the per-sample processing stage of the graphics pipeline, after
/// fragment processing has been performed. Because per-sample
/// processing is performed at the last stage of the pipeline,
/// fragments that are discarded at this stage will cause the
/// highest waste of GPU resources compared to any method that
/// would have discarded vertices or fragments earlier in the
/// pipeline. There are situations in which scissor testing has
/// to be used to control whether fragments are discarded or not.
/// An example of such a situation is when performing the viewport
/// transform on vertices is necessary but a subset of the generated
/// fragments should not have an effect on the stencil buffer or
/// blend with the color buffer.
//
/// To apply a view, you have to assign it to the render target.
/// Then, objects drawn in this render target will be
/// affected by the view until you use another view.

43
src/SFML/Graphics/RenderTarget.cpp
View File

@ -161,6 +161,10 @@ void RenderTarget::clear(const Color& color)
// Unbind texture to fix RenderTexture preventing clear
applyTexture(nullptr);
// Apply the view (scissor testing can affect clearing)
if (!m_cache.enable || m_cache.viewChanged)
applyCurrentView();
glCheck(glClearColor(color.r / 255.f, color.g / 255.f, color.b / 255.f, color.a / 255.f));
glCheck(glClear(GL_COLOR_BUFFER_BIT));
}
@ -200,6 +204,17 @@ IntRect RenderTarget::getViewport(const View& view) const
}
////////////////////////////////////////////////////////////
IntRect RenderTarget::getScissor(const View& view) const
{
const auto [width, height] = Vector2f(getSize());
const FloatRect& scissor = view.getScissor();
return IntRect(Rect<long>({std::lround(width * scissor.left), std::lround(height * scissor.top)},
{std::lround(width * scissor.width), std::lround(height * scissor.height)}));
}
////////////////////////////////////////////////////////////
Vector2f RenderTarget::mapPixelToCoords(const Vector2i& point) const
{
@ -506,6 +521,7 @@ void RenderTarget::resetGLStates()
glCheck(glDisable(GL_LIGHTING));
glCheck(glDisable(GL_DEPTH_TEST));
glCheck(glDisable(GL_ALPHA_TEST));
glCheck(glDisable(GL_SCISSOR_TEST));
glCheck(glEnable(GL_TEXTURE_2D));
glCheck(glEnable(GL_BLEND));
glCheck(glMatrixMode(GL_MODELVIEW));
@ -513,6 +529,7 @@ void RenderTarget::resetGLStates()
glCheck(glEnableClientState(GL_VERTEX_ARRAY));
glCheck(glEnableClientState(GL_COLOR_ARRAY));
glCheck(glEnableClientState(GL_TEXTURE_COORD_ARRAY));
m_cache.scissorEnabled = false;
m_cache.glStatesSet = true;
// Apply the default SFML states
@ -557,8 +574,30 @@ void RenderTarget::applyCurrentView()
{
// Set the viewport
const IntRect viewport = getViewport(m_view);
const int top = static_cast<int>(getSize().y) - (viewport.top + viewport.height);
glCheck(glViewport(viewport.left, top, viewport.width, viewport.height));
const int viewportTop = static_cast<int>(getSize().y) - (viewport.top + viewport.height);
glCheck(glViewport(viewport.left, viewportTop, viewport.width, viewport.height));
// Set the scissor rectangle and enable/disable scissor testing
if (m_view.getScissor() == FloatRect({0, 0}, {1, 1}))
{
if (m_cache.scissorEnabled)
{
glCheck(glDisable(GL_SCISSOR_TEST));
m_cache.scissorEnabled = false;
}
}
else
{
const IntRect pixelScissor = getScissor(m_view);
const int scissorTop = static_cast<int>(getSize().y) - (pixelScissor.top + pixelScissor.height);
glCheck(glScissor(pixelScissor.left, scissorTop, pixelScissor.width, pixelScissor.height));
if (!m_cache.scissorEnabled)
{
glCheck(glEnable(GL_SCISSOR_TEST));
m_cache.scissorEnabled = true;
}
}
// Set the projection matrix
glCheck(glMatrixMode(GL_PROJECTION));

12
src/SFML/Graphics/RenderTextureImplFBO.cpp
View File

@ -572,6 +572,14 @@ void RenderTextureImplFBO::updateTexture(unsigned int)
if (frameBuffer && multiSampleFrameBuffer)
{
// Scissor testing affects framebuffer blits as well
// Since we don't want scissor testing to interfere with our copying, we temporarily disable it for the blit if it is enabled
GLboolean scissorEnabled = GL_FALSE;
glCheck(glGetBooleanv(GL_SCISSOR_TEST, &scissorEnabled));
if (scissorEnabled == GL_TRUE)
glCheck(glDisable(GL_SCISSOR_TEST));
// Set up the blit target (draw framebuffer) and blit (from the read framebuffer, our multisample FBO)
glCheck(GLEXT_glBindFramebuffer(GLEXT_GL_DRAW_FRAMEBUFFER, frameBuffer->object));
glCheck(GLEXT_glBlitFramebuffer(0,
@ -585,6 +593,10 @@ void RenderTextureImplFBO::updateTexture(unsigned int)
GL_COLOR_BUFFER_BIT,
GL_NEAREST));
glCheck(GLEXT_glBindFramebuffer(GLEXT_GL_DRAW_FRAMEBUFFER, multiSampleFrameBuffer->object));
// Re-enable scissor testing if it was previously enabled
if (scissorEnabled == GL_TRUE)
glCheck(glEnable(GL_SCISSOR_TEST));
}
}
}

12
src/SFML/Graphics/Texture.cpp
View File

@ -582,6 +582,14 @@ void Texture::update(const Texture& texture, const Vector2u& dest)
if ((sourceStatus == GLEXT_GL_FRAMEBUFFER_COMPLETE) && (destStatus == GLEXT_GL_FRAMEBUFFER_COMPLETE))
{
// Scissor testing affects framebuffer blits as well
// Since we don't want scissor testing to interfere with our copying, we temporarily disable it for the blit if it is enabled
GLboolean scissorEnabled = GL_FALSE;
glCheck(glGetBooleanv(GL_SCISSOR_TEST, &scissorEnabled));
if (scissorEnabled == GL_TRUE)
glCheck(glDisable(GL_SCISSOR_TEST));
// Blit the texture contents from the source to the destination texture
glCheck(GLEXT_glBlitFramebuffer(0,
texture.m_pixelsFlipped ? static_cast<GLint>(texture.m_size.y) : 0,
@ -593,6 +601,10 @@ void Texture::update(const Texture& texture, const Vector2u& dest)
static_cast<GLint>(dest.y + texture.m_size.y), // Destination rectangle
GL_COLOR_BUFFER_BIT,
GL_NEAREST));
// Re-enable scissor testing if it was previously enabled
if (scissorEnabled == GL_TRUE)
glCheck(glEnable(GL_SCISSOR_TEST));
}
else
{

21
src/SFML/Graphics/View.cpp
View File

@ -87,6 +87,20 @@ void View::setViewport(const FloatRect& viewport)
}
////////////////////////////////////////////////////////////
void View::setScissor(const FloatRect& scissor)
{
assert(scissor.left >= 0.0f && scissor.left <= 1.0f && "scissor.left must lie within [0, 1]");
assert(scissor.top >= 0.0f && scissor.top <= 1.0f && "scissor.top must lie within [0, 1]");
assert(scissor.width >= 0.0f && "scissor.width must lie within [0, 1]");
assert(scissor.height >= 0.0f && "scissor.height must lie within [0, 1]");
assert(scissor.left + scissor.width <= 1.0f && "scissor.left + scissor.width must lie within [0, 1]");
assert(scissor.top + scissor.height <= 1.0f && "scissor.top + scissor.height must lie within [0, 1]");
m_scissor = scissor;
}
////////////////////////////////////////////////////////////
void View::reset(const FloatRect& rectangle)
{
@ -127,6 +141,13 @@ const FloatRect& View::getViewport() const
}
////////////////////////////////////////////////////////////
const FloatRect& View::getScissor() const
{
return m_scissor;
}
////////////////////////////////////////////////////////////
void View::move(const Vector2f& offset)
{

14
test/Graphics/View.test.cpp
View File

@ -24,6 +24,7 @@ TEST_CASE("[Graphics] sf::View")
CHECK(view.getSize() == sf::Vector2f(1000, 1000));
CHECK(view.getRotation() == sf::Angle::Zero);
CHECK(view.getViewport() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getScissor() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getTransform() == sf::Transform(0.002f, 0, -1, 0, -0.002f, 1, 0, 0, 1));
CHECK(view.getInverseTransform() == Approx(sf::Transform(500, 0, 500, 0, -500, 500, 0, 0, 1)));
}
@ -35,6 +36,7 @@ TEST_CASE("[Graphics] sf::View")
CHECK(view.getSize() == sf::Vector2f(400, 600));
CHECK(view.getRotation() == sf::Angle::Zero);
CHECK(view.getViewport() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getScissor() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getTransform() == Approx(sf::Transform(0.005f, 0, -1.05f, 0, -0.00333333f, 1.06667f, 0, 0, 1)));
CHECK(view.getInverseTransform() == Approx(sf::Transform(200, 0, 210, 0, -300, 320, 0, 0, 1)));
}
@ -46,6 +48,7 @@ TEST_CASE("[Graphics] sf::View")
CHECK(view.getSize() == sf::Vector2f(1080, 1920));
CHECK(view.getRotation() == sf::Angle::Zero);
CHECK(view.getViewport() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getScissor() == sf::FloatRect({0, 0}, {1, 1}));
CHECK(view.getTransform() == Approx(sf::Transform(0.00185185f, 0, -0.962963f, 0, -0.00104167f, 1, 0, 0, 1)));
CHECK(view.getInverseTransform() == Approx(sf::Transform(540, 0, 520, 0, -960, 960, 0, 0, 1)));
}
@ -93,6 +96,15 @@ TEST_CASE("[Graphics] sf::View")
CHECK(view.getViewport() == sf::FloatRect({150, 250}, {500, 750}));
CHECK(view.getTransform() == Approx(sf::Transform(0.002f, 0, -1, 0, -0.002f, 1, 0, 0, 1)));
CHECK(view.getInverseTransform() == Approx(sf::Transform(500, 0, 500, 0, -500, 500, 0, 0, 1)));
CHECK(view.getScissor() == sf::FloatRect({0, 0}, {1, 1}));
}
SECTION("Set/get scissor")
{
sf::View view;
view.setScissor({{0, 0}, {0.5f, 1}});
CHECK(view.getScissor() == sf::FloatRect({0, 0}, {0.5, 1}));
CHECK(view.getViewport() == sf::FloatRect({0, 0}, {1, 1}));
}
SECTION("reset()")
@ -102,11 +114,13 @@ TEST_CASE("[Graphics] sf::View")
view.setSize({600, 900});
view.setRotation(sf::degrees(15));
view.setViewport({{150, 250}, {500, 750}});
view.setScissor({{0.2f, 0.3f}, {0.4f, 0.5f}});
view.reset({{1, 2}, {3, 4}});
CHECK(view.getCenter() == sf::Vector2f(2.5f, 4));
CHECK(view.getSize() == sf::Vector2f(3, 4));
CHECK(view.getRotation() == sf::Angle::Zero);
CHECK(view.getViewport() == sf::FloatRect({150, 250}, {500, 750}));
CHECK(view.getScissor() == sf::FloatRect({0.2f, 0.3f}, {0.4f, 0.5f}));
CHECK(view.getTransform() == Approx(sf::Transform(0.666667f, 0, -1.66667f, 0, -0.5f, 2, 0, 0, 1)));
CHECK(view.getInverseTransform() == Approx(sf::Transform(1.5f, 0, 2.5f, 0, -2, 4, 0, 0, 1)));
}