JosephFerano/opengl-playground
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Predefine rects where we're going to place the textures

Browse Source
This commit is contained in:
Joseph Ferano 2023-10-11 22:49:49 +07:00
parent 7cc36d4f54
commit 8326b110df
1 changed files with 37 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
game/tools/texturepacker.c
View File

@ -9,13 +9,16 @@
#define STB_IMAGE_WRITE_IMPLEMENTATION #define STB_IMAGE_WRITE_IMPLEMENTATION
#include "stb_image_write.h" #include "stb_image_write.h"
struct image { typedef struct image_t {
char* filename; char* filename;
unsigned char* image_data; unsigned char* image_data;
int width; int id, width, height, channels;
int height; } image_t;
int channels;
}; typedef struct tex_rect_t {
image_t* img;
int x,y,w,h;
} tex_rect_t;
int main(int argc, char* argv[]) { int main(int argc, char* argv[]) {
if (argc == 1) { if (argc == 1) {
@ -26,7 +29,7 @@ int main(int argc, char* argv[]) {
fprintf(stderr, "Please provide at least 2 images to pack"); fprintf(stderr, "Please provide at least 2 images to pack");
exit(-1); exit(-1);
} }
struct image* images = calloc(argc - 1, sizeof(struct image)); image_t* images = calloc(argc - 1, sizeof(image_t));
if (images == NULL) { if (images == NULL) {
fprintf(stderr, "Failed to alloc image data array"); fprintf(stderr, "Failed to alloc image data array");
exit(-1); exit(-1);
@ -36,7 +39,7 @@ int main(int argc, char* argv[]) {
//------------------------------------- //-------------------------------------
int image_count = argc - 1; int image_count = argc - 1;
for (int i = 0; i < argc - 1; i++) { for (int i = 0; i < argc - 1; i++) {
struct image* img = &images[i]; image_t* img = &images[i];
img->filename = argv[i+1]; img->filename = argv[i+1];
int result = stbi_info(img->filename, &img->width, &img->height, &img->channels); int result = stbi_info(img->filename, &img->width, &img->height, &img->channels);
@ -47,16 +50,20 @@ int main(int argc, char* argv[]) {
} }
} }
//------------------------------------- //-------------------------------------
// Now run the packing algorithm // Now run the packing algorithm. This is super inefficient
// Note: How to get the minimum power of 2 texture size. Note that this is still // texture packing but I just want to get it working first
// very inefficient because we're just naively putting them all at 0
// x = log2(max(width, height))
// width or height = 2 ** (x + 1)
// This is super inefficient texture packing but I just want to get it working first
//------------------------------------- //-------------------------------------
tex_rect_t* tex_rects = calloc(image_count, sizeof(tex_rect_t));
int totalh = 0, maxw = 0; int totalh = 0, maxw = 0;
for (int i = 0; i < image_count; i++) { for (int i = 0; i < image_count; i++) {
tex_rects[i] = (tex_rect_t){
&images[i],
0, // Put them all on the 1st column for now
totalh,
images[i].width,
images[i].height,
};
totalh += images[i].height; totalh += images[i].height;
if (images[i].width > maxw) { if (images[i].width > maxw) {
maxw = images[i].width; maxw = images[i].width;
@ -65,7 +72,6 @@ int main(int argc, char* argv[]) {
int max = totalh > maxw ? totalh : maxw; int max = totalh > maxw ? totalh : maxw;
int exp = (int)log2(max) + 1; int exp = (int)log2(max) + 1;
int size = (int)pow(2, exp); int size = (int)pow(2, exp);
unsigned char* buf = calloc(size*size*4, sizeof(char));
//------------------------------------- //-------------------------------------
// Now load the data into memory, for now, let's just load all images in one go, // Now load the data into memory, for now, let's just load all images in one go,
@ -90,24 +96,25 @@ int main(int argc, char* argv[]) {
// we need to make this work, since we're "hardcoding" the positions of the textures // we need to make this work, since we're "hardcoding" the positions of the textures
//------------------------------------- //-------------------------------------
int atlasrow = 0; unsigned char* buf = calloc(size*size*4, sizeof(char));
int channels = images[0].channels;
for (int i = 0; i < image_count; i++) { for (int i = 0; i < image_count; i++) {
int width = images[i].width; tex_rect_t rect = tex_rects[i];
int length = images[i].width * images[i].height * images[i].channels; int buf_row = rect.y;
int color_row = 0; int buf_col = rect.x;
int color_col = 0; int img_row = 0;
int c = 0; int img_col = 0;
while (c < length) { while (img_row < rect.h) {
int bidx = atlasrow * maxw * 4 + color_row; int buf_idx = (buf_row * maxw + buf_col) * channels;
int iidx = color_col * width * 4 + color_row; int img_idx = (img_row * rect.w + img_col) * channels;
buf[bidx] = images[i].image_data[iidx]; for (int j = 0; j < channels; j++) {
color_row++; buf[buf_idx + j] = images[i].image_data[img_idx + j];
if (color_row > width * 4) { }
color_row = 0; img_col++; buf_col++;
color_col += 1; if (img_col > rect.w) {
atlasrow += 1; img_col = buf_col = 0;
img_row++; buf_row++;
} }
c++;
} }
} }