I have a question about using the sf::Shape from the SFML graphic library. In my game i use sf::RectangleShapes. For example the UserInterface or the player. Here is a peace of code:
std::unique_ptr<sf::RectangleShape> rect;
sf::RenderTarget ⌖
sf::RenderStates &stats;
void SfUIComponents::SfBaseRectangle::draw()
{
target.draw(*rect, stats);
}
When I load the shader with a file like here:
If(shader->loadFromFile(vertex, fragment)){ loaded = true;}
effect->loadFromFile("wave.vert","blur.frag");
Before I draw the rectangle :
void SfShader::activate()
{
stats.shader = shader;
}
The text which I draw too show the effect but the rectangles aren't visible. So ms question without showing more code. Is it possible to use the sfml shader for rectangles which are simple fill with white color?
You can use the shader when drawing into your render.
You can do this by creating a "sf::RenderState", and setting it's shader:
sf::RenderState rs;
sf::Shader effect;
effect.loadFromFile("wave.vert","blur.frag");
rs.shader = &effect;
window.draw(rect , rs);
If you don't need to use more information from the RenderState (like a texture), you can directly pass the shader to the draw function:
sf::Shader effect;
effect.loadFromFile("wave.vert","blur.frag");
window.draw(rect , &effect);
Related
I've been working around to make a little light shader.
It works perfectly, I mean, the light fades as it's supposed to, it's a circle around my character moving with it.
It could be perfect only if that resizing event wasn't existing.
When SFML resizes the window, it enlarges everything, but in a strange way. It enlarged everything but shaders.
I tried to resize my window (I love resizing pixel graph games, I find it most beautiful. So I don't want to prevent the resizing event).
Here's my shader :
uniform vec3 light;
void main(void) {
float distance = sqrt(pow(gl_FragCoord.x - light.x, 2) + pow(gl_FragCoord.y - light.y, 2));
float alpha = 1.;
if (distance <= light.z) {
alpha = (1.0 / light.z) * distance;
}
gl_FragColor = vec4(0., 0., 0., alpha);
}
So, the problem is, my window is showed at 1280 x 736 (to fit with 32x32 textures), and I have a 1920 x 1080 monitor. When I enlarge the window to fit in 1920 x 1080 (title bar included), the whole thing resizes correctly, everything's fine, but the shader is now 1920x1080 (minus the title bar). So the shader needs different coordinates (what's supposed to be in x = 32, y = 0 is, for the shader, in x = 48 y = 0).
So I was wondering, is it possible to enlarge the shader with the whole window ? Should I use events or something like that ?
Thanks for your answers ^^
EDIT : Here's some pics :
So this is the light shader before it resizes (it's dark everywhere but on the player, like it's supposed to be).
Then I resize the window, the player doesn't move, the textures fit the entire window, but the light moved.
So, to explain correctly, when I resize the window, I want everything to fit the window, so it's full of textures, but when I do that, the coordinates given to my shader are the ones before resizing, and if I move it moves as if I didn't resize the window, so the light is never on my player again.
I'm not sure it's clearer, but I tried my best.
EDIT2 : Here's my code which calls the shader :
void Graphics::UpdateLight() {
short radius = 65; // 265 on the pictures
int x = m_game->GetPlayer()->GetSprite()->getPosition().x + CASE_LEN / 2; // Setting on the middle of the player sprite (CASE_LEN is a const which contains the size of a case (here 32))
int y = HEIGHT - (m_game->GetPlayer()->GetSprite()->getPosition().y + CASE_LEN / 2); // (the "HEIGHT -" part was set because it seems that y = 0 is on the bottom of the texture for GLSL)
sf::Vector3f shaderLight;
shaderLight.x = x;
shaderLight.y = y;
shaderLight.z = radius;
m_lightShader.setParameter("light", shaderLight);
}
The code snippet you're showing really only updates the shader coordinates (and from a quick glimpse it looks fine). The bug most likely happens somewhere where you're actually drawing things.
I'd use a completely different approach, because your shader approach might get rather tedious once you're rendering multiple things, other light sources, etc.
As such I'd suggest you render a light map to a render texture (which would essentially be like "black = no light, color = light of that color").
Rather than trying to explain everything in text, I've written a quick commented example program which will draw a window on screen and move some light sources over a background image (I've used the one that comes with SFML's shader example):
There are no requirements other than having a file called "background.jpg" in your startup path.
Feel free to copy this code or use it for inspiration. Just keep in mind this isn't optimized and really just a quick edit to show the general idea.
#include <SFML/Graphics.hpp>
#include <vector>
#include <cmath>
const float PI = 3.1415f;
struct Light
{
sf::Vector2f position;
sf::Color color;
float radius;
};
int main()
{
// Let's setup a window
sf::RenderWindow window(sf::VideoMode(640, 480), "SFML Lights");
window.setVerticalSyncEnabled(false);
window.setFramerateLimit(60);
// Create something simple to draw
sf::Texture texture;
texture.loadFromFile("background.jpg");
sf::Sprite background(texture);
// Setup everything for the lightmap
sf::RenderTexture lightmapTex;
// We're using a 512x512 render texture for max. compatibility
// On modern hardware it could match the window resolution of course
lightmapTex.create(512, 512);
sf::Sprite lightmap(lightmapTex.getTexture());
// Scale the sprite to fill the window
lightmap.setScale(640 / 512.f, 480 / 512.f);
// Set the lightmap's view to the same as the window
lightmapTex.setView(window.getDefaultView());
// Drawable helper to draw lights
// We'll just have to adjust the first vertex's color to tint it
sf::VertexArray light(sf::PrimitiveType::TriangleFan);
light.append({sf::Vector2f(0, 0), sf::Color::White});
// This is inaccurate, but for demo purposes…
// This could be more elaborate to allow better graduation etc.
for (float i = 0; i <= 2 * PI; i += PI * .125f)
light.append({sf::Vector2f(std::sin(i), std::cos(i)), sf::Color::Transparent});
// Setup some lights
std::vector<Light> lights;
lights.push_back({sf::Vector2f(50.f, 50.f), sf::Color::White, 100.f });
lights.push_back({sf::Vector2f(350.f, 150.f), sf::Color::Red, 150.f });
lights.push_back({sf::Vector2f(150.f, 250.f), sf::Color::Yellow, 200.f });
lights.push_back({sf::Vector2f(250.f, 450.f), sf::Color::Cyan, 100.f });
// RenderStates helper to transform and draw lights
sf::RenderStates rs(sf::BlendAdd);
while (window.isOpen()) {
sf::Event event;
while (window.pollEvent(event)) {
switch (event.type) {
case sf::Event::Closed:
window.close();
break;
}
}
bool flip = false; // simple toggle to animate differently
// Draw the light map
lightmapTex.clear(sf::Color::Black);
for(Light &l : lights)
{
// Apply all light attributes and render it
// Reset the transformation
rs.transform = sf::Transform::Identity;
// Move the light
rs.transform.translate(l.position);
// And scale it (this could be animated to create flicker)
rs.transform.scale(l.radius, l.radius);
// Adjust the light color (first vertex)
light[0].color = l.color;
// Draw the light
lightmapTex.draw(light, rs);
// To make things a bit more interesting
// We're moving the lights
l.position.x += flip ? 2 : -2;
flip = !flip;
if (l.position.x > 640)
l.position.x -= 640;
else if (l.position.x < 0)
l.position.x += 640;
}
lightmapTex.display();
window.clear(sf::Color::White);
// Draw the background / game
window.draw(background);
// Draw the lightmap
window.draw(lightmap, sf::BlendMultiply);
window.display();
}
}
I try to integrate Bullet Physics' debug drawing interface into QML, so I have to implement a drawLine() method.
void drawLine(const btVector3 &from, const btVector3 &to, const btVector3 &color);
What I tried is that I inherited an item, that is used in the scene, from both QQuickItem3D and btIDebugDraw. In drawLine(), I add the lines to a member vector. In Qt's drawItem(), I iterate over the lines and use OpenGL calls to render them. However, they do not appear on screen.
How can I draw the lines in 3D space and from the correct camera view?
void DebugDrawer::drawItem(QGLPainter *painter)
{
if (lines_.size() < 1)
return;
// Draw current lines
painter->modelViewMatrix().push();
glBegin(GL_LINES);
for (auto &line : lines_) {
glColor3f(line.color.getX(), line.color.getY(), line.color.getZ());
glVertex3f(line.from.getX(), line.from.getY(), line.from.getZ());
glVertex3f(line.to.getX(), line.to.getY(), line.to.getZ());
}
glEnd();
painter->modelViewMatrix().pop();
// Reset buffer
lines_.clear();
}
I ended up using QtQuick's line class and set its vertices using setVertices() in Bullet's flushLines() method.
I'm making a game in C++ with SDL, and I want to render particles with SDL_FillRect().
I've played with the code for hours, but no matter what I do, the particles are not drawing.
This is the code in my Render function (I made sure that I was in fact calling the function):
void Particle::Render()
{
SDL_Rect rect;
rect.x = x;
rect.y = y;
//rect.w = Particle::Particle_Size;
//rect.h = Particle::Particle_Size;
rect.w = 8;
rect.h = 8;
surface = SDL_CreateRGBSurface(SDL_SWSURFACE,8,8,32,0,0,0,0);
if(SDL_FillRect(surface,&rect,SDL_MapRGB(surface->format,0,0,0)) != 0) printf("Error");
//SDL_RenderCopy(renderer,texture,NULL,&rect);
}
The console isn't printing "Error", so the SDL_FillRect() is successful. However, no rects are being drawn to the screen.
I tried creating a texture with SDL_CreateTextureFromSurface() with that surface passed in, and then used SDL_RenderCopy, which is commented out in the above function, but it worked before I commented it out. I want to use SDL_FillRect so I could have colored textures though.
Am I missing anything?
I think you could use this function to do what you are looking for:
SDL_RenderFillRect()
https://wiki.libsdl.org/SDL_RenderFillRect
You would have to set the renderer color before with:
SDL_SetRenderDrawColor();
I think you could also update the window surface to get what you have to work.
That would use
SDL_UpdateWindowSurface().
https://wiki.libsdl.org/SDL_UpdateWindowSurface?highlight=%28%5CbCategoryVideo%5Cb%29%7C%28CategoryEnum%29%7C%28CategoryStruct%29
Hope it helps!
The SDL_CreateRGBSurface() function creates an off-screen surface. If you want to draw to the screen, you will have to draw to the surface returned by SDL_GetWindowSurface().
That is, if you are using SDL 2.0.
I have a fairly simple DirectX 11 framework setup that I want to use for various 2D simulations. I am currently trying to implement the 2D Wave Equation on the GPU. It requires I keep the grid state of the simulation at 2 previous timesteps in order to compute the new one.
How I went about it was this - I have a class called FrameBuffer, which has the following public methods:
bool Initialize(D3DGraphicsObject* graphicsObject, int width, int height);
void BeginRender(float clearRed, float clearGreen, float clearBlue, float clearAlpha) const;
void EndRender() const;
// Return a pointer to the underlying texture resource
const ID3D11ShaderResourceView* GetTextureResource() const;
In my main draw loop I have an array of 3 of these buffers. Every loop I use the textures from the previous 2 buffers as inputs to the next frame buffer and I also draw any user input to change the simulation state. I then draw the result.
int nextStep = simStep+1;
if (nextStep > 2)
nextStep = 0;
mFrameArray[nextStep]->BeginRender(0.0f,0.0f,0.0f,1.0f);
{
mGraphicsObj->SetZBufferState(false);
mQuad->GetRenderer()->RenderBuffers(d3dGraphicsObj->GetDeviceContext());
ID3D11ShaderResourceView* texArray[2] = { mFrameArray[simStep]->GetTextureResource(),
mFrameArray[prevStep]->GetTextureResource() };
result = mWaveShader->Render(d3dGraphicsObj, mQuad->GetRenderer()->GetIndexCount(), texArray);
if (!result)
return false;
// perform any extra input
I_InputSystem *inputSystem = ServiceProvider::Instance().GetInputSystem();
if (inputSystem->IsMouseLeftDown()) {
int x,y;
inputSystem->GetMousePos(x,y);
int width,height;
mGraphicsObj->GetScreenDimensions(width,height);
float xPos = MapValue((float)x,0.0f,(float)width,-1.0f,1.0f);
float yPos = MapValue((float)y,0.0f,(float)height,-1.0f,1.0f);
mColorQuad->mTransform.position = Vector3f(xPos,-yPos,0);
result = mColorQuad->Render(&viewMatrix,&orthoMatrix);
if (!result)
return false;
}
mGraphicsObj->SetZBufferState(true);
}
mFrameArray[nextStep]->EndRender();
prevStep = simStep;
simStep = nextStep;
ID3D11ShaderResourceView* currTexture = mFrameArray[nextStep]->GetTextureResource();
// Render texture to screen
mGraphicsObj->SetZBufferState(false);
mQuad->SetTexture(currTexture);
result = mQuad->Render(&viewMatrix,&orthoMatrix);
if (!result)
return false;
mGraphicsObj->SetZBufferState(true);
The problem is nothing is happening. Whatever I draw appears on the screen(I draw using a small quad) but no part of the simulation is actually ran. I can provide the shader code if required, but I am certain it works since I've implemented this before on the CPU using the same algorithm. I'm just not certain how well D3D render targets work and if I'm just drawing wrong every frame.
EDIT 1:
Here is the code for the begin and end render functions of the frame buffers:
void D3DFrameBuffer::BeginRender(float clearRed, float clearGreen, float clearBlue, float clearAlpha) const {
ID3D11DeviceContext *context = pD3dGraphicsObject->GetDeviceContext();
context->OMSetRenderTargets(1, &(mRenderTargetView._Myptr), pD3dGraphicsObject->GetDepthStencilView());
float color[4];
// Setup the color to clear the buffer to.
color[0] = clearRed;
color[1] = clearGreen;
color[2] = clearBlue;
color[3] = clearAlpha;
// Clear the back buffer.
context->ClearRenderTargetView(mRenderTargetView.get(), color);
// Clear the depth buffer.
context->ClearDepthStencilView(pD3dGraphicsObject->GetDepthStencilView(), D3D11_CLEAR_DEPTH, 1.0f, 0);
void D3DFrameBuffer::EndRender() const {
pD3dGraphicsObject->SetBackBufferRenderTarget();
}
Edit 2 Ok, I after I set up the DirectX debug layer I saw that I was using an SRV as a render target while it was still bound to the Pixel stage in out of the shaders. I fixed that by setting shader resources to NULL after I render with the wave shader, but the problem still persists - nothing actually gets ran or updated. I took the render target code from here and slightly modified it, if its any help: http://rastertek.com/dx11tut22.html
Okay, as I understand correct you need a multipass-rendering to texture.
Basiacally you do it like I've described here: link
You creating SRVs with both D3D11_BIND_SHADER_RESOURCE and D3D11_BIND_RENDER_TARGET bind flags.
You ctreating render targets from textures
You set first texture as input (*SetShaderResources()) and second texture as output (OMSetRenderTargets())
You Draw()*
then you bind second texture as input, and third as output
Draw()*
etc.
Additional advices:
If your target GPU capable to write to UAVs from non-compute shaders, you can use it. It is much more simple and less error prone.
If your target GPU suitable, consider using compute shader. It is a pleasure.
Don't forget to enable DirectX debug layer. Sometimes we make obvious errors and debug output can point to them.
Use graphics debugger to review your textures after each draw call.
Edit 1:
As I see, you call BeginRender and OMSetRenderTargets only once, so, all rendering goes into mRenderTargetView. But what you need is to interleave:
SetSRV(texture1);
SetRT(texture2);
Draw();
SetSRV(texture2);
SetRT(texture3);
Draw();
SetSRV(texture3);
SetRT(backBuffer);
Draw();
Also, we don't know what is mRenderTargetView yet.
so, before
result = mColorQuad->Render(&viewMatrix,&orthoMatrix);
somewhere must be OMSetRenderTargets .
Probably, it s better to review your Begin()/End() design, to make resource binding more clearly visible.
Happy coding! =)
I'm a openFrameworks newbie. I am learning basic 2d drawing which is all great so far. I have drawn a circle using:
ofSetColor(0x333333);
ofFill;
ofCircle(100,650,50);
My question is how do I give the circle a variable name so that I can manipulate in the mousepressed method? I tried adding a name before the ofCircle
theball.ofSetColor(0x333333);
theball.ofFill;
theball.ofCircle(100,650,50);
but get I 'theball' was not declared in this scope error.
As razong pointed out that's not how OF works. OF (to the best of my knowledge) provides a handy wrapper to a lot of OpenGL stuff. So you should use OF calls to effect the current drawing context (as opposed to thinking of a canvas with sprite objects or whatever). I usually integrate that kind of thing into my objects. So lets say you have a class like this...
class TheBall {
protected:
ofColor col;
ofPoint pos;
public:
// Pass a color and position when we create ball
TheBall(ofColor ballColor, ofPoint ballPosition) {
col = ballColor;
pos = ballPosition;
}
// Destructor
~TheBall();
// Make our ball move across the screen a little when we call update
void update() {
pos.x++;
pos.y++;
}
// Draw stuff
void draw(float alpha) {
ofEnableAlphaBlending(); // We activate the OpenGL blending with the OF call
ofFill(); //
ofSetColor(col, alpha); // Set color to the balls color field
ofCircle(pos.x, pos.y, 5); // Draw command
ofDisableAlphaBlending(); // Disable the blending again
}
};
Ok cool, I hope that makes sense. Now with this structure you can do something like the following
testApp::setup() {
ofColor color;
ofPoint pos;
color.set(255, 0, 255); // A bright gross purple
pos.x, pos.y = 50;
aBall = new TheBall(color, pos);
}
testApp::update() {
aBall->update()
}
testApp::draw() {
float alpha = sin(ofGetElapsedTime())*255; // This will be a fun flashing effect
aBall->draw(alpha)
}
Happy programming.
Happy designing.
You can't do it that way. ofCircle is a global drawing method and draws just a circle.
You can declare a variable (or better three int for rgb - since you can't use ofColor as an argument for ofSetColor) that store the color for the circle and modify it in the mousepressed method.
Inside the draw method use your variables for ofSetColor before rendering the circle.