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Replaced decompiled code with bresenhams algorithm. Gfx_draw_line finished.

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Duncan Frost
2014-05-11 21:25:18 +01:00
parent 45532da9c6
commit 84342b07d2
1 changed files with 54 additions and 82 deletions
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136
src/gfx.c
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@@ -144,7 +144,7 @@ void gfx_draw_line_on_buffer(rct_drawpixelinfo *dpi, char colour, int y, int x,
/**
*
* Draws a line on dpi if within dpi boundaries
* rct2: 0x00684466
* dpi (edi)
* x1 (ax)
@@ -155,106 +155,78 @@ void gfx_draw_line_on_buffer(rct_drawpixelinfo *dpi, char colour, int y, int x,
*/
void gfx_draw_line(rct_drawpixelinfo *dpi, int x1, int y1, int x2, int y2, int colour)
{
//RCT2_CALLPROC_X(0x00684466, x1, y1, x2, y2, 0, dpi, colour);
//return;
// Check to make sure the line is within the drawing area
if ((x1 < dpi->x) && (x2 < dpi->x)){
return;//jump to 0x68474B
return;
}
if ((y1 < dpi->y) && (y2 < dpi->y)){
return;//jump to 0x68474B
return;
}
if ((x1 > (dpi->x + dpi->width)) && (x2 > (dpi->x + dpi->width))){
return;//jump to 0x68474B
if ((x1 >(dpi->x + dpi->width)) && (x2 >(dpi->x + dpi->width))){
return;
}
if ((y1 > (dpi->y + dpi->height)) && (y2 > (dpi->y + dpi->height))){
return;//jump to 0x68474B
return;
}
RCT2_GLOBAL(0xEDF84A, uint16) = (uint16)(0xFFFF & colour);
//Bresenhams algorithm
int bits_pointer;
bits_pointer = dpi->bits;
RCT2_GLOBAL(0x9ABDB8, uint32) = bits_pointer;
RCT2_GLOBAL(0x9ABDBC, uint16) = dpi->x;
RCT2_GLOBAL(0x9ABDBE, uint16) = dpi->y;
RCT2_GLOBAL(0x9ABDC0, uint16) = dpi->width;
RCT2_GLOBAL(0x9ABDC2, uint16) = dpi->height;
RCT2_GLOBAL(0x9ABDC4, uint16) = dpi->pitch;
int edi = y1;
int esi = x1;
int ebp = colour & 0xFFFF;
int x_diff, y_diff;
x_diff = x2 - x1;
//If vertical plot points upwards
int steep = abs(y2 - y1) > abs(x2 - x1);
if (steep){
int temp_y2 = y2;
int temp_x2 = x2;
y2 = x1;
x2 = y1;
y1 = temp_x2;
x1 = temp_y2;
}
//If line is right to left swap direction
if (x1 > x2){
x_diff = -x_diff;
int ax = x_diff;
int dx = y2 - y1;
if (dx < 0){
RCT2_CALLPROC_X(0x6846C5, ax, x2, x_diff, dx, esi, edi, ebp);
return;
//jump 0x6846C5
}
RCT2_GLOBAL(0xEDF846, uint16) = x_diff;
RCT2_GLOBAL(0xEDF848, uint16) = y2 - y1;
if (dx > x_diff){
RCT2_CALLPROC_X(0x684691, ax, x2, x_diff, dx, esi, edi, ebp);
return;
//jump 0x684691
}
ax--;
if (ax < 0)return;
x_diff /= 2;
x_diff = -x_diff;
ebp = 0;
return;//not finished
int temp_y2 = y2;
int temp_x2 = x2;
y2 = y1;
x2 = x1;
y1 = temp_y2;
x1 = temp_x2;
}
int ax = x_diff;
y_diff = y2 - y1;
if (y1 > y2){
RCT2_CALLPROC_X(0x6845AB, ax, x2, x_diff, y_diff, esi, edi, ebp);
return;
//jump 0x6845AB
}
RCT2_GLOBAL(0xEDF846, uint16) = x_diff;
RCT2_GLOBAL(0xEDF848, uint16) = y_diff;
if ((y2 - y1) > (x2 - x1)){
RCT2_CALLPROC_X(0x68456A, ax, x2, x_diff, y_diff, esi, edi, ebp);
return;
//jump 0x68456A
}
ax--;
if (ax < 0){
RCT2_CALLPROC_X(0x684568, ax, x2, x_diff, y_diff, esi, edi, ebp);
return;//jump 0x684568
}
x_diff /= 2;
x_diff = -x_diff;
ebp = 0;
for (int i = ax; i >= 0; i--){
ebp++;
x_diff += y_diff;
if (x_diff <= 0){
if (i-1 < 0){
gfx_draw_line_on_buffer(dpi, (uint16)(0xFFFF & colour), edi, ebp, esi);
return;
}
continue;
int delta_x = x2 - x1;
int delta_y = abs(y2 - y1);
int error = delta_x / 2;
int y_step;
int y = y1;
//Direction of step
if (y1 < y2)y_step = 1;
else y_step = -1;
for (int x = x1, x_start = x1, no_pixels = 1; x < x2; ++x,++no_pixels){
//Vertical lines are drawn 1 pixel at a time
if (steep)gfx_draw_line_on_buffer(dpi, colour, x, y, 1);
error -= delta_y;
if (error < 0){
//Non vertical lines are drawn with as many pixels in a horizontal line as possible
if (!steep)gfx_draw_line_on_buffer(dpi, colour, y, x_start, no_pixels);
//Reset non vertical line vars
x_start = x + 1;
no_pixels = 1;
y += y_step;
error += delta_x;
}
//Catch the case of the last line
if (x + 1 == x2 && !steep){
gfx_draw_line_on_buffer(dpi, colour, y, x_start, no_pixels);
}
x_diff -= x2 - x1;
gfx_draw_line_on_buffer(dpi, (uint16)(0xFFFF & colour), edi, ebp, esi);
esi += ebp;
edi++;
ebp = 0;
}
return;
}
/**