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Optimized line buffer and rendering sequence slightly

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This commit is contained in:
jespergravgaard 2020-05-08 09:07:46 +02:00
parent 6da9a8f9f8
commit aa66273149
1 changed files with 17 additions and 19 deletions
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36
src/test/kc/complex/polygon/polygon.c
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@ -14,7 +14,7 @@
#undef DEBUG
// The line buffer
char* const LINE_BUFFER = 0x4000;
char* const LINE_BUFFER = 0x2000;
// The two charsets used as screen buffers
char* const CANVAS1 = 0x3000;
char* const CANVAS2 = 0x3800;
@ -28,7 +28,7 @@ char* const PETSCII = 0x1000;
// The current canvas being rendered to the screen - in D018 format.
char volatile canvas_show_memory = toD018(SCREEN, CANVAS2);
// Flag signalling that the canvas on screen needs to be updated.
// Flag signalling that the canvas on screen needs to be updated.
// Set to 1 by the renderer when a new canvas is ready for showing, and to 0 by the raster when the canvas is shown on screen.
char volatile canvas_show_flag = 0;
@ -38,8 +38,6 @@ char align(0x100) SINTAB[0x140] = kickasm {{
}};
char* COSTAB = SINTAB+0x40;
void plot(char* canvas, char x, char y);
void main() {
// Clear the console
memset(CONSOLE, ' ', 40*25);
@ -66,7 +64,7 @@ void main() {
// Set text color
textcolor(WHITE);
char p0_idx = 0x88;
char p0_idx = 0xf0;
char p1_idx = p0_idx+15;
char p2_idx = p0_idx+170;
@ -91,21 +89,21 @@ void main() {
p0_idx++;
p1_idx++;
p2_idx++;
// Fill canvas
eorfill(LINE_BUFFER, canvas);
// Wait until the canvas on screen has been switched before starting work on the next frame
VICII->BORDER_COLOR = RED;
while(canvas_show_flag) {}
VICII->BORDER_COLOR = BLACK;
// Swap canvas to show on screen (using XOR)
canvas_show_memory ^= toD018(SCREEN,CANVAS1)^toD018(SCREEN,CANVAS2);
// Fill canvas
eorfill(LINE_BUFFER, canvas);
// swap canvas being rendered to (using XOR)
canvas ^= (CANVAS1^CANVAS2);
// Swap canvas to show on screen (using XOR)
canvas_show_memory ^= toD018(SCREEN,CANVAS1)^toD018(SCREEN,CANVAS2);
// Set flag used to signal when the canvas has been shown
canvas_show_flag = 1;
// Read and display cycles
clock_t cyclecount = clock()-CLOCKS_PER_INIT;
gotoxy(0,24);
gotoxy(0,24);
printf("frame: %02x cycles: %6lu", p0_idx, cyclecount);
//printf("(%02x,%02x)-(%02x,%02x)", x0, y0, x1, y1);
}
@ -166,7 +164,7 @@ void line(char* canvas, char x1, char y1, char x2, char y2) {
char sy = sgn_u8(y2-y1);
if(sx==0xff) {
// The sign of the x-difference determines if this is a line at the top of the face
// being filled or a line at the bottom of the face. Because the points are organized in a clockwise
// being filled or a line at the bottom of the face. Because the points are organized in a clockwise
// fashion any line pointing right is filled below the line and any line pointing left is filled above
// If this line is pointing left then move it down one pixel to ensure the fill is stopped correctly
y++; y2++;
@ -174,8 +172,8 @@ void line(char* canvas, char x1, char y1, char x2, char y2) {
if(dx > dy) {
// X is the driver - plot every X using bresenham
char e = dx/2;
do {
plot(canvas, x, y);
do {
plot(x, y);
x += sx;
e += dy;
if(dx < e) {
@ -183,32 +181,32 @@ void line(char* canvas, char x1, char y1, char x2, char y2) {
e -= dx;
}
} while (x != x2);
plot(canvas, x, y);
plot(x, y);
} else {
// Y is the driver - only plot one plot per X
char e = dy/2;
plot(canvas, x, y);
plot(x, y);
do {
y += sy;
e += dx;
if(dy<e) {
x += sx;
e -= dy;
plot(canvas, x, y);
plot(x, y);
}
} while (y != y2);
}
}
// Column offsets
unsigned int plot_column[16] = { 0, 1*128, 2*128, 3*128, 4*128, 5*128, 6*128, 7*128, 8*128, 9*128, 10*128, 11*128, 12*128, 13*128, 14*128, 15*128 };
char* plot_column[16] = { LINE_BUFFER+0, LINE_BUFFER+1*128, LINE_BUFFER+2*128, LINE_BUFFER+3*128, LINE_BUFFER+4*128, LINE_BUFFER+5*128, LINE_BUFFER+6*128, LINE_BUFFER+7*128, LINE_BUFFER+8*128, LINE_BUFFER+9*128, LINE_BUFFER+10*128, LINE_BUFFER+11*128, LINE_BUFFER+12*128, LINE_BUFFER+13*128, LINE_BUFFER+14*128, LINE_BUFFER+15*128 };
// The bits used for plotting a pixel
char plot_bit[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01};
// Plot a single point on the canvas
void plot(char* canvas, char x, char y) {
inline void plot(char x, char y) {
// Find the canvas column
char* column = canvas + plot_column[x/8];
char* column = plot_column[x/8];
// Plot the bit
column[y] |= plot_bit[x&7];
}