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Generic functions (surface/pixel fill/blend).

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Line antialiasing.
Circle antialiasing.

svn-id: r31844
This commit is contained in:
Vicent Marti 2008-05-03 19:50:38 +00:00
parent b50d430192
commit 8c043f53ed
2 changed files with 260 additions and 89 deletions
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194
graphics/VectorRenderer.cpp
View File

@ -31,8 +31,10 @@
namespace Graphics {
inline uint32 fp_sqroot( uint32 x );
VectorRenderer *createRenderer() {
return new VectorRendererSpec<uint16,ColorMasks<565>>;
return new VectorRendererAA<uint16,ColorMasks<565>>;
}
@ -49,12 +51,20 @@ void vector_renderer_test( OSystem *_system ) {
_system->grabOverlay((OverlayColor*)_screen.pixels, _screen.w);
vr->setSurface( &_screen );
vr->setColor( 255, 255, 255 );
vr->setColor( 255, 0, 0 );
vr->fillSurface();
vr->setColor( 255, 255, 0 );
_system->showOverlay();
while( true ) { // draw!!
vr->drawLine( 25, 100, 25, 150 );
vr->setColor( 255, 255, 255 );
vr->fillSurface();
vr->setColor( 255, 0, 0 );
vr->drawLine( 25, 25, 125, 300 );
vr->drawCircle( 250, 250, 100 );
_system->copyRectToOverlay((OverlayColor*)_screen.getBasePtr(0, 0), _screen.w, 0, 0, _screen.w, _screen.w);
_system->updateScreen();
_system->delayMillis(100);
@ -63,10 +73,9 @@ void vector_renderer_test( OSystem *_system ) {
_system->hideOverlay();
}
template<typename PixelType, typename PixelFormat>
void VectorRendererSpec<PixelType,PixelFormat>::
drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy) {
drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy) {
PixelType *ptr = (PixelType *)_activeSurface->getBasePtr(x1, y1);
int pitch = surfacePitch();
int xdir = (x2 > x1) ? 1 : -1;
@ -111,76 +120,77 @@ drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy) {
*ptr = (PixelType)_color;
}
template<typename PixelType, typename PixelFormat>
void VectorRendererAA<PixelType,PixelFormat>::
drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy) {
blendPixelPtr( PixelType *ptr, uint8 alpha ) {
register int idst = *ptr;
register int isrc = _color;
*ptr = (PixelType)(
(PixelFormat::kRedMask & ((idst & PixelFormat::kRedMask) +
((int)(((int)(isrc & PixelFormat::kRedMask) -
(int)(idst & PixelFormat::kRedMask)) * alpha) >>8))) |
(PixelFormat::kGreenMask & ((idst & PixelFormat::kGreenMask) +
((int)(((int)(isrc & PixelFormat::kGreenMask) -
(int)(idst & PixelFormat::kGreenMask)) * alpha) >>8))) |
(PixelFormat::kBlueMask & ((idst & PixelFormat::kBlueMask) +
((int)(((int)(isrc & PixelFormat::kBlueMask) -
(int)(idst & PixelFormat::kBlueMask)) * alpha) >>8))) );
}
template<typename PixelType, typename PixelFormat>
void VectorRendererAA<PixelType,PixelFormat>::
drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy) {
PixelType *ptr = (PixelType *)_activeSurface->getBasePtr(x1, y1);
int pitch = surfacePitch();
int xdir = (x2 > x1) ? 1 : -1;
uint16 error_tmp, error_acc, gradient;
int error_line, error_tmp, weight;
int error_total = 0;
uint8 line_r, line_g, line_b;
uint8 bg_r, bg_g, bg_b;
*ptr = (PixelType)_color;
colorToRGB<PixelFormat>(_color, line_r, line_g, line_b);
if ( dx > dy ) {
gradient = (uint32)(dy<<16)/(uint32)dx;
error_acc = 0;
uint line_lum = (line_r >> 2) + (line_g >> 1) + (line_b >> 3);
uint bg_lum;
while( --dx ) {
error_tmp = error_acc;
error_acc += gradient;
// first pixel, should be perfectly accurate so no fading out
*ptr = (PixelType)_color;
if ( error_acc <= error_tmp )
ptr += pitch;
#define __WULINE_PUTPIXEL( pixel_ptr ) { \
colorToRGB<PixelFormat>((PixelType)*(pixel_ptr), bg_r, bg_g, bg_b); \
bg_lum = (bg_r >> 2) + (bg_g >> 1) + (bg_b >> 3); \
weight = (line_lum < bg_lum) ? error_total >> 8 : (error_total >> 8)^0xFF; \
*(pixel_ptr) = RGBToColor<PixelFormat>( \
antialiasingBlendWeight(line_r, bg_r, weight), \
antialiasingBlendWeight(line_g, bg_g, weight), \
antialiasingBlendWeight(line_b, bg_b, weight)); \
ptr += xdir;
blendPixelPtr( ptr, (error_acc >> 8) ^ 0xFF );
blendPixelPtr( ptr + pitch, (error_acc >> 8) & 0xFF );
}
} else {
gradient = (uint32)(dx<<16)/(uint32)dy;
error_acc = 0;
while( --dy ) {
error_tmp = error_acc;
error_acc += gradient;
if ( error_acc <= error_tmp )
ptr += xdir;
ptr += pitch;
blendPixelPtr( ptr, (error_acc >> 8) ^ 0xFF );
blendPixelPtr( ptr + xdir, (error_acc >> 8) & 0xFF );
}
}
// draw from top to bottom while fading out.
// optimized for mostly vertical lines
if (dy > dx) {
error_line = (dx << 16) / dy;
while (--dy) {
error_tmp = error_total;
error_total += error_line;
if (error_total <= error_tmp)
ptr += xdir; // move right or left
ptr += pitch; // move down
__WULINE_PUTPIXEL(ptr);
__WULINE_PUTPIXEL(ptr + xdir);
}
} else { // optimized for mostly horizontal lines
error_line = (dy << 16) / dx;
while (--dx) {
error_tmp = error_total;
error_total += error_line;
if (error_total <= error_tmp)
ptr += pitch; // move down
ptr += xdir; // move left or right
__WULINE_PUTPIXEL(ptr);
__WULINE_PUTPIXEL(ptr + pitch);
}
} // end of line direction cases
// last pixel, also perfectly accurate.
ptr = (PixelType *)_activeSurface->getBasePtr(x2, y2);
*ptr = (PixelType)_color;
putPixel( x2, y2 );
}
template<typename PixelType, typename PixelFormat>
void VectorRendererSpec<PixelType,PixelFormat>::
drawLine(int x1, int x2, int y1, int y2) {
drawLine(int x1, int y1, int x2, int y2) {
// we draw from top to bottom
if (y2 < y1) {
SWAP(x1, x2);
@ -219,7 +229,71 @@ drawLine(int x1, int x2, int y1, int y2) {
}
} else { // generic lines, use the standard algorithm...
drawLineAlg(x1, x2, y1, y2, dx, dy);
drawLineAlg(x1, y1, x2, y2, dx, dy);
}
}
inline uint32 fp_sqroot( uint32 x ) {
register uint32 root, remHI, remLO, testDIV, count;
root = 0;
remHI = 0;
remLO = x;
count = 23;
do {
remHI = (remHI<<2) | (remLO>>30);
remLO <<= 2;
root <<= 1;
testDIV = (root<<1) + 1;
if ( remHI >= testDIV ) {
remHI -= testDIV;
root++;
}
} while( count-- );
return root;
}
template<typename PixelType, typename PixelFormat>
void VectorRendererAA<PixelType,PixelFormat>::
drawCircleAlg(int x1, int y1, int r) {
#define __CIRCLE_SIM(x,y,a) { \
blendPixel( x1 + (x), y1 + (y), a ); \
blendPixel( x1 + (x), y1 - (y), a ); \
blendPixel( x1 - (y), y1 + (x), a ); \
blendPixel( x1 + (y), y1 + (x), a ); \
blendPixel( x1 - (x), y1 + (y), a ); \
blendPixel( x1 - (x), y1 - (y), a ); \
blendPixel( x1 + (y), y1 - (x), a ); \
blendPixel( x1 - (y), y1 - (x), a ); \
}
// first quadrant
/*#define __CIRCLE_SIM(x,y,a) { \
blendPixel( x1 + (x), y1 - (y), a ); \
blendPixel( x1 + (y), y1 - (x), a ); \
}*/
int x = r;
int y = 0;
uint32 rsq = (r*r)<<16;
uint32 T = 0, oldT;
__CIRCLE_SIM( x, y, 255 );
while( x > y++ )
{
oldT = T;
T = fp_sqroot( rsq - ((y*y)<<16) ) ^ 0xFFFF;
if ( T < oldT )
x--;
__CIRCLE_SIM( x, y, (T>>8) ^ 0xFF );
__CIRCLE_SIM( x-1, y, (T>>8) & 0xFF );
}
}

155
graphics/VectorRenderer.h
View File

@ -37,7 +37,7 @@ void vector_renderer_test( OSystem *_system );
/**
* VectorRenderer: The core Vector Renderer Class
*
* This virtual class which exposes the API with all the vectorial
* This virtual class exposes the API with all the vectorial
* rendering functions that may be used to draw on a given Surface.
*
* This class must be instantiated as one of its children, which implement
@ -60,7 +60,16 @@ public:
* @param y1 Vertical (Y) coordinate for the line start
* @param y2 Vertical (Y) coordinate for the line end
*/
virtual void drawLine(int x1, int x2, int y1, int y2) = 0;
virtual void drawLine(int x1, int y1, int x2, int y2) = 0;
/**
* Draws a circle centered at (x,y) with radius r.
*
* @param x Horizontal (X) coordinate for the center of the circle
* @param y Vertical (Y) coordinate for the center of the circle
* @param r Radius of the circle.
*/
virtual void drawCircle( int x, int y, int r ) = 0;
/**
* Gets the pixel pitch for the current drawing surface.
@ -96,21 +105,47 @@ public:
virtual void setColor(uint8 r, uint8 g, uint8 b) = 0;
/**
* Set the active painting color for the renderer, including alpha
* intensity. All the drawing from then on will be done with that color,
* unless specified otherwise.
* Sets the active drawing surface. All drawing from this
* point on will be done on that surface.
*
* @param r value of the red color byte
* @param g value of the green color byte
* @param b value of the blue color byte
* @param a value of the alpha byte
* @param surface Pointer to a Surface object.
*/
virtual void setColor(uint8 r, uint8 g, uint8 b, uint8 a) = 0;
virtual void setSurface( Surface *surface ){
_activeSurface = surface;
}
/**
* Fills the active surface with the currently active drawing color.
*/
virtual void fillSurface() = 0;
/**
* Clears the active surface.
*/
virtual void clearSurface() {
byte *src = (byte *)_activeSurface->pixels;
memset( src, 0, _activeSurface->w * _activeSurface->h * _activeSurface->bytesPerPixel );
}
/**
* Draws a single pixel on the surface with the given coordinates and
* the currently active drawing color.
*
* @param x Horizontal coordinate of the pixel.
* @param y Vertical coordinate of the pixel.
*/
inline virtual void putPixel( int x, int y ) = 0;
/**
* Blends a single pixel on the surface with the given coordinates, with
* the currently active drawing color and with the given Alpha intensity.
*
* @param x Horizontal coordinate of the pixel.
* @param y Vertical coordinate of the pixel.
* @param alpha Alpha intensity of the pixel (0-255)
*/
inline virtual void blendPixel( int x, int y, uint8 alpha ) = 0;
protected:
/**
@ -125,8 +160,16 @@ protected:
* @param dx Horizontal (X) increasement.
* @param dy Vertical (Y) increasement.
*/
virtual void drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy) = 0;
virtual void drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy) = 0;
/**
* Specific circle drawing algorithm with symmetry. Must be implemented
* on each renderer.
*
* @param x Horizontal (X) coordinate for the center of the circle
* @param y Vertical (Y) coordinate for the center of the circle
* @param r Radius of the circle.
*/
virtual void drawCircleAlg(int x, int y, int r) = 0;
Surface *_activeSurface; /** Pointer to the surface currently being drawn */
@ -156,11 +199,16 @@ protected:
template<typename PixelType, typename PixelFormat>
class VectorRendererSpec : public VectorRenderer {
public:
/**
* @see VectorRenderer::drawLine()
*/
void drawLine(int x1, int x2, int y1, int y2);
void drawCircle( int x, int y, int r ) {
drawCircleAlg( x, y, r );
}
/**
* @see VectorRenderer::setColor()
*/
@ -175,6 +223,33 @@ class VectorRendererSpec : public VectorRenderer {
_color = RGBToColor<PixelFormat>(r, g, b);
}
/**
* @see VectorRenderer::fillSurface()
*/
void fillSurface() {
PixelType *ptr = (PixelType *)_activeSurface->getBasePtr(0, 0);
int s = _activeSurface->w * _activeSurface->h;
Common::set_to(ptr, ptr + s, (PixelType)_color);
}
/**
* @see VectorRenderer::putPixel()
*/
inline void putPixel( int x, int y ) {
PixelType *ptr = (PixelType *)_activeSurface->getBasePtr(x, y);
*ptr = _color;
}
/**
* On the Specialized Renderer, alpha blending is not supported.
*
* @see VectorRenderer::blendPixel()
*/
virtual inline void blendPixel( int x, int y, uint8 alpha ) {
if ( alpha > 0 )
putPixel( x, y );
}
protected:
/*
@ -186,8 +261,11 @@ protected:
*
* @see VectorRenderer::drawLineAlg()
*/
virtual void drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy);
virtual void drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy);
/**
* @see VectorRenderer::drawCircleAlg()
*/
virtual void drawCircleAlg(int x, int y, int r) {}
PixelType _color; /** Color currently being used to draw on the renderer */
@ -218,27 +296,46 @@ protected:
*
* @see VectorRenderer::drawLineAlg()
*/
void drawLineAlg(int x1, int x2, int y1, int y2, int dx, int dy);
void drawLineAlg(int x1, int y1, int x2, int y2, int dx, int dy);
/**
* Calculates the blending weight (relative luminosity) value for
* a given pixel, based on the distance to the ideal line.
* Used for blending pixels in the Wu AA algorithm.
* Perform alpha blending on top of a given pixel, not on a given
* coordinate (just so we don't have to recalculate the surface
* pointer while we are blending consecutive pixels).
*
* @param line_color Byte value of a color component (R/G/B) of the color used to draw the line.
* @param line_color Byte value of a color component (R/G/B) of the color used to draw the BG.
* @param weight Weight of the pixel as calculated by Wu's algorithm.
* @return The new color value for the given component.
* Everything from blendPixel() applies here.
*
* @see VectorRenderer::blendPixel()
* @param ptr Pointer to the pixel where we must draw
* @param alpha Intensity of the pixel (0-255).
*/
inline uint8 antialiasingBlendWeight(uint8 line_color, uint8 bg_color, uint weight) {
uint8 value;
if (bg_color > line_color) {
value = weight / 255 * (bg_color - line_color) + bg_color;
} else {
value = weight / 255 * (line_color - bg_color) + line_color;
}
return value;
inline void blendPixelPtr( PixelType *ptr, uint8 alpha );
/**
* @see VectorRenderer::blendPixel()
*
* The AA renderer does support alpha blending. Special cases are
* handled separately.
*/
inline void blendPixel( int x, int y, uint8 alpha ) {
if ( alpha == 0 )
return;
else if ( alpha < 255 )
blendPixelPtr( (PixelType*)_activeSurface->getBasePtr(x, y), alpha );
else
putPixel( x, y );
}
/**
* "Wu's Circle Antialiasing Algorithm" as published by Xiaolin Wu, July 1991
* Based on the theoretical concept of the algorithm.
*
* Implementation of Wu's algorithm for circles using fixed point arithmetics.
* Could be quite fast.
*
* @see VectorRenderer::drawCircleAlg()
*/
virtual void drawCircleAlg(int x, int y, int r);
};
} // end of namespace Graphics