ugfx/demos/modules/gdisp/streaming/main.c

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/*
* Copyright (c) 2012, 2013, Joel Bodenmann aka Tectu <joel@unormal.org>
* Copyright (c) 2012, 2013, Andrew Hannam aka inmarket
* Derived from the 2011 IOCCC submission by peter.eastman@gmail.com
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the <organization> nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "gfx.h"
#include <math.h>
/**
* NOTE:
*
* This demo uses floating point operations. Don't expect it to work with any
* speed unless your processor has an FPU.
*
* If you see garbage inside the ball as it is running rather than the red and yellow
* checkerboard pattern then the fast invsqrt() function in GMISC does not work on
* your processor.
*
* You can modify the implementation of invsqrt() by firstly defining
* #define GMISC_INVSQRT_MIXED_ENDIAN TRUE
* in your gfxconf.h file.
*
* If it still doesn't work then instead define
* #define GMISC_INVSQRT_REAL_SLOW TRUE
* in your gfxconf.h file. This should always work although it will probably be slow.
*/
#define BALLCOLOR1 Red
#define BALLCOLOR2 Yellow
#define WALLCOLOR HTML2COLOR(0x303030)
#define BACKCOLOR HTML2COLOR(0xC0C0C0)
#define FLOORCOLOR HTML2COLOR(0x606060)
#define SHADOWALPHA (255-255*0.2)
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int main(void) {
coord_t width, height, x, y, radius, ballx, bally, dx, floor;
coord_t minx, miny, maxx, maxy;
coord_t ballcx, ballcy;
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color_t colour;
float ii, spin, dy, spinspeed, h, f, g;
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gfxInit();
width = gdispGetWidth();
height = gdispGetHeight();
radius=height/5+height%2+1; // The ball radius
ii = 1.0/radius; // radius as easy math
floor=height/5-1; // floor position
spin=0.0; // current spin angle on the ball
spinspeed=0.1; // current spin speed of the ball
ballx=width/2; // ball x position (relative to the ball center)
bally=height/4; // ball y position (relative to the ball center)
dx=.01*width; // motion in the x axis
dy=0.0; // motion in the y axis
ballcx = 12*radius/5; // ball x diameter including the shadow
ballcy = 21*radius/10; // ball y diameter including the shadow
minx = miny = 0; maxx = width; maxy = height; // The clipping window for this frame.
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while(1) {
// Draw one frame
gdispStreamStart(minx, miny, maxx-minx, maxy-miny);
for (y=miny; h = (bally-y)*ii, y<maxy; y++) {
for (x=minx; x < maxx; x++) {
g=(ballx-x)*ii;
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f=-.3*g+.954*h;
if (g*g < 1-h*h) {
/* The inside of the ball */
if ((((int)(9-spin+(.954*g+.3*h)*invsqrt(1-f*f))+(int)(2+f*2))&1))
colour = BALLCOLOR1;
else
colour = BALLCOLOR2;
} else {
// The background (walls and floor)
if (y > height-floor) {
if (x < height-y || height-y > width-x)
colour = WALLCOLOR;
else
colour = FLOORCOLOR;
} else if (x<floor || x>width-floor)
colour = WALLCOLOR;
else
colour = BACKCOLOR;
// The ball shadow is darker
if (g*(g+.4)+h*(h+.1) < 1)
colour = gdispBlendColor(colour, Black, SHADOWALPHA);
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}
gdispStreamColor(colour); /* pixel to the LCD */
}
}
gdispStreamStop();
// Force a display update if the controller supports it
gdispFlush();
// Calculate the new frame size (note this is a drawing optimisation only)
minx = ballx - radius; miny = bally - radius;
maxx = minx + ballcx; maxy = miny + ballcy;
if (dx > 0) maxx += dx; else minx += dx;
if (dy > 0) maxy += dy; else miny += dy;
if (minx < 0) minx = 0;
if (maxx > width) maxx = width;
if (miny < 0) miny = 0;
if (maxy > height) maxy = height;
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// Motion
spin += spinspeed;
ballx += dx; bally += dy;
dx = ballx < radius || ballx > width-radius ? spinspeed=-spinspeed,-dx : dx;
dy = bally > height-1.75*floor ? -.04*height : dy+.002*height;
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}
}