Add basic shapes to draw things on screen

* Line, Rect Functions
 * Test screen
This commit is contained in:
Aaron Mueller 2009-12-10 23:23:02 +01:00
parent e12b581fc8
commit 28c3ec0268
3 changed files with 82 additions and 4 deletions

View file

@ -2,7 +2,7 @@
# Compiler # Compiler
CC= gcc CC= gcc
# Compiler flags # Compiler flags
CFLAGS= -Wall -Os -std=c99 CFLAGS= -Wall -std=c99 -ggdb
# Libraries # Libraries
CLIBS= `sdl-config --cflags` -lSDL -lGL CLIBS= `sdl-config --cflags` -lSDL -lGL
####### Commands ####### Commands

View file

@ -1,17 +1,94 @@
#include "SDL.h" #include "SDL.h"
#include <math.h>
#include <stdbool.h>
#include "draw.h" #include "draw.h"
#include "config.h" #include "config.h"
void drawPixel(int x, int y, int color) { void drawPixel(int x, int y, int color) {
unsigned int *p = (unsigned int*)screen->pixels; unsigned int *p = (unsigned int*)screen->pixels;
int lineOffset = y * (screen->pitch/4); int lineOffset = y * (screen->pitch/4);
p[lineOffset+x] = color; p[lineOffset+x] = color;
} }
void drawScreen() { int _sign(float a) {
Uint32 black = SDL_MapRGB(screen->format, 0xff, 0xff, 0xff); return a > 0 ? 1 : (a < 0 ? -1 : 0);
drawPixel(SCREEN_WIDTH/2, SCREEN_HEIGHT/2, black); }
void drawLine(int x1, int y1, int x2, int y2, int color) {
float u, s, v, d1x, d1y, d2x, d2y, m, n;
int x = x1, y = y1;
u = x2-x1;
v = y2-y1;
d1x = d2x = _sign(u);
d1y = _sign(v);
d2y = 0;
m = abs(u);
n = abs(v);
if (m <= n) {
d2x = 0;
d2y = _sign(v);
m = abs(v);
n = abs(u);
}
s = (int)(m/2);
for (int i=0; i<round(m); i++) {
drawPixel(x, y, color);
s += n;
if (s >= m) {
s -= m;
x += d1x;
y += d1y;
} else {
x += d2x;
y += d2y;
}
}
}
void drawRect(int x1, int y1, int x2, int y2, int color, bool filled) {
int tmp;
if (x1 > x2) { tmp = x1; x2 = x1; x1 = tmp; }
if (y1 > y2) { tmp = y1; y2 = y1; y1 = tmp; }
if (filled) {
for (int i=y1; i<=y2; i++) drawLine(x1, i, x2, i, color);
} else {
drawLine(x1, y1, x2, y1, color);
drawLine(x1, y1, x1, y2, color);
drawLine(x2, y1, x2, y2, color);
drawLine(x1, y2, x2, y2, color);
}
}
// TODO: Write some code in here!
void drawCircle(int x, int y, int radius, int color, bool filled) {
}
void drawScreen() {
Uint32 white = SDL_MapRGB(screen->format, 255, 255, 255);
drawPixel(SCREEN_WIDTH/2, SCREEN_HEIGHT/2, white);
for (int i=0; i<250; i+=1)
drawLine(200, 300-i, 600, 300+i, SDL_MapRGB(screen->format, 0, 0, i));
drawRect(0, 50, 200, 300, white, true);
drawRect(600, 300, 799, 550, white, false);
// Random dots
for (int i=0; i<100; i++)
drawPixel(rand()%200+600, rand()%250+300, white);
drawCircle(SCREEN_WIDTH/2, SCREEN_HEIGHT/2, 100, white, true);
drawCircle(SCREEN_WIDTH/2, SCREEN_HEIGHT/2, 104, white, false);
for (int i=0; i<=600; i++) drawLine(0, i, 799, i, white);
} }

View file

@ -19,6 +19,7 @@ int main(int argc, char **argv) {
} }
// Draw the stuff on the screen and "flip" th the next frame // Draw the stuff on the screen and "flip" th the next frame
SDL_FillRect(screen, NULL, 0x000000);
drawScreen(); drawScreen();
SDL_Flip(screen); SDL_Flip(screen);
} }