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mirror of https://github.com/OpenRCT2/OpenRCT2 synced 2025-12-24 00:03:11 +01:00
Files
OpenRCT2/src/drawing/drawing_fast.cpp
2016-02-23 17:33:54 +01:00

189 lines
8.0 KiB
C++

extern "C"
{
#include "drawing.h"
}
// This will have -1 (0xffffffff) for (val <= 0), 0 otherwise, so it can act as a mask
// This is expected to generate
// sar eax, 0x1f (arithmetic shift right by 31)
#define less_or_equal_zero_mask(val) (((val - 1) >> (sizeof(val) * 8 - 1)))
template<int image_type, int zoom_level>
static void FASTCALL DrawRLESprite2(const uint8* source_bits_pointer,
uint8* dest_bits_pointer,
const uint8* palette_pointer,
const rct_drawpixelinfo *dpi,
int source_y_start,
int height,
int source_x_start,
int width)
{
int zoom_amount = 1 << zoom_level;
int zoom_mask = 0xFFFFFFFF << zoom_level;
uint8* next_dest_pointer = dest_bits_pointer;
int line_width = (dpi->width >> zoom_level) + dpi->pitch;
const int source_y_start_mask = less_or_equal_zero_mask(source_y_start + 1);
source_y_start += zoom_amount & source_y_start_mask;
next_dest_pointer += line_width & source_y_start_mask;
height -= zoom_amount & source_y_start_mask;
//For every line in the image
for (int i = 0; i < height; i += zoom_amount) {
int y = source_y_start + i;
uint8 i2 = i >> zoom_level;
//The first part of the source pointer is a list of offsets to different lines
//This will move the pointer to the correct source line.
const uint8 *next_source_pointer = source_bits_pointer + ((uint16*)source_bits_pointer)[y];
uint8* loop_dest_pointer = next_dest_pointer + line_width * i2;
uint8 last_data_line = 0;
//For every data section in the line
while (!last_data_line) {
const uint8* source_pointer = next_source_pointer;
uint8* dest_pointer = loop_dest_pointer;
int no_pixels = *source_pointer++;
//gap_size is the number of non drawn pixels you require to
//jump over on your destination
uint8 gap_size = *source_pointer++;
//The last bit in no_pixels tells you if you have reached the end of a line
last_data_line = no_pixels & 0x80;
//Clear the last data line bit so we have just the no_pixels
no_pixels &= 0x7f;
//Have our next source pointer point to the next data section
next_source_pointer = source_pointer + no_pixels;
//Calculates the start point of the image
int x_start = gap_size - source_x_start;
const int x_diff = x_start & ~zoom_mask;
const int x_mask = ~less_or_equal_zero_mask(x_diff);
no_pixels -= x_diff;
x_start += ~zoom_mask & x_mask;
source_pointer += (x_start&~zoom_mask) & x_mask;
// This will have -1 (0xffffffff) for (x_start <= 0), 0 otherwise
int sign = less_or_equal_zero_mask(x_start);
dest_pointer += (x_start >> zoom_level) & ~sign;
//If the start is negative we require to remove part of the image.
//This is done by moving the image pointer to the correct position.
source_pointer -= x_start & sign;
//The no_pixels will be reduced in this operation
no_pixels += x_start & sign;
//Reset the start position to zero as we have taken into account all moves
x_start &= ~sign;
int x_end = x_start + no_pixels;
//If the end position is further out than the whole image
//end position then we need to shorten the line again
const int pixels_till_end = x_end - width;
//Shorten the line
no_pixels -= pixels_till_end & ~(less_or_equal_zero_mask(pixels_till_end));
//Finally after all those checks, copy the image onto the drawing surface
//If the image type is not a basic one we require to mix the pixels
if (image_type & IMAGE_TYPE_USE_PALETTE) {//In the .exe these are all unraveled loops
for (; no_pixels > 0; no_pixels -= zoom_amount, source_pointer += zoom_amount, dest_pointer++) {
uint8 al = *source_pointer;
uint8 ah = *dest_pointer;
if (image_type & IMAGE_TYPE_MIX_BACKGROUND)
al = palette_pointer[(((uint16)al << 8) | ah) - 0x100];
else
al = palette_pointer[al];
*dest_pointer = al;
}
} else if (image_type & IMAGE_TYPE_MIX_BACKGROUND) {//In the .exe these are all unraveled loops
//Doesnt use source pointer ??? mix with background only?
//Not Tested
for (; no_pixels > 0; no_pixels -= zoom_amount, dest_pointer++) {
uint8 pixel = *dest_pointer;
pixel = palette_pointer[pixel];
*dest_pointer = pixel;
}
} else
{
if (zoom_amount == 1) {
no_pixels &= ~less_or_equal_zero_mask(no_pixels);
memcpy(dest_pointer, source_pointer, no_pixels);
} else {
for (; no_pixels > 0; no_pixels -= zoom_amount, source_pointer += zoom_amount, dest_pointer++) {
*dest_pointer = *source_pointer;
}
}
}
}
}
}
#define DrawRLESpriteHelper2(image_type, zoom_level) \
DrawRLESprite2<image_type, zoom_level>(source_bits_pointer, dest_bits_pointer, palette_pointer, dpi, source_y_start, height, source_x_start, width)
template<int image_type>
static void FASTCALL DrawRLESprite1(const uint8* source_bits_pointer,
uint8* dest_bits_pointer,
const uint8* palette_pointer,
const rct_drawpixelinfo *dpi,
int source_y_start,
int height,
int source_x_start,
int width)
{
int zoom_level = dpi->zoom_level;
switch (zoom_level) {
case 0: DrawRLESpriteHelper2(image_type, 0); break;
case 1: DrawRLESpriteHelper2(image_type, 1); break;
case 2: DrawRLESpriteHelper2(image_type, 2); break;
case 3: DrawRLESpriteHelper2(image_type, 3); break;
default: assert(false); break;
}
}
#define DrawRLESpriteHelper1(image_type) \
DrawRLESprite1<image_type>(source_bits_pointer, dest_bits_pointer, palette_pointer, dpi, source_y_start, height, source_x_start, width)
extern "C"
{
/**
* Transfers readied images onto buffers
* This function copies the sprite data onto the screen
* rct2: 0x0067AA18
*/
void FASTCALL gfx_rle_sprite_to_buffer(const uint8* source_bits_pointer,
uint8* dest_bits_pointer,
const uint8* palette_pointer,
const rct_drawpixelinfo *dpi,
int image_type,
int source_y_start,
int height,
int source_x_start,
int width)
{
if (image_type & IMAGE_TYPE_USE_PALETTE)
{
if (image_type & IMAGE_TYPE_MIX_BACKGROUND)
{
DrawRLESpriteHelper1(IMAGE_TYPE_USE_PALETTE | IMAGE_TYPE_MIX_BACKGROUND);
}
else
{
DrawRLESpriteHelper1(IMAGE_TYPE_USE_PALETTE);
}
}
else if (image_type & IMAGE_TYPE_MIX_BACKGROUND)
{
DrawRLESpriteHelper1(IMAGE_TYPE_MIX_BACKGROUND);
}
else
{
DrawRLESpriteHelper1(0);
}
}
}