Add 'gentexture' utility

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@177 84d2e878-0bd5-11dd-ad15-13eda11d74c5

2 files changed, 199 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index a3b6e6b..5539d18 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,10 +1,12 @@
-bin_PROGRAMS = thrust3d
+bin_PROGRAMS = thrust3d gentexture
 
 thrust3d_SOURCES = main.c model.c render.c physics.c game.c texture.c utils.c audio.c render-text.c
 
 #glcheck_SOURCES = glcheck.c
 #glcheck_LDADD = -lglut
 
+gentexture_SOURCES = gentexture.c
+
 AM_CFLAGS = -Wall
 AM_CPPFLAGS = -DDATADIR=\""$(datadir)"/thrust3d\"
 
diff --git a/src/gentexture.c b/src/gentexture.c
new file mode 100644
index 0000000..d43f8b5
--- /dev/null
+++ b/src/gentexture.c
@@ -0,0 +1,196 @@
+/*
+ * gentexture.c
+ *
+ * Generate normal map stuff
+ *
+ * (c) 2008 Thomas White <taw27@cam.ac.uk>
+ *
+ *  thrust3d - a silly game
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <png.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+int main(int argc, char *argv[]) {
+
+	FILE *fh;
+	png_bytep header;
+	png_structp png_ptr;
+	png_infop info_ptr;
+	png_infop end_info;
+	unsigned int width;
+	unsigned int height;
+	unsigned int bit_depth;
+	unsigned int channels;
+	png_bytep *row_pointers;
+	unsigned int x;
+	unsigned int y;
+	uint8_t *texels;
+	char *filename;
+	char *outfilename;
+	
+	filename = argv[1];
+	outfilename = argv[2];
+	
+	/* Open file */
+	fh = fopen(filename, "rb");
+	if ( !fh ) {
+		fprintf(stderr, "Couldn't open texture file '%s'\n", filename);
+		return 1;
+	}
+	
+	/* Check it's actually a PNG file */
+	header = malloc(8);
+	fread(header, 1, 8, fh);
+	if ( png_sig_cmp(header, 0, 8)) {
+		fprintf(stderr, "Texture file '%s' is not a PNG file.\n", filename);
+		free(header);
+		fclose(fh);
+		return 1;
+	}
+	free(header);
+	
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if ( !png_ptr ) {
+		fprintf(stderr, "Couldn't create PNG read structure.\n");
+		fclose(fh);
+		return 1;
+	}
+	
+	info_ptr = png_create_info_struct(png_ptr);
+	if ( !info_ptr ) {
+		png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL);
+		fprintf(stderr, "Couldn't create PNG info structure.\n");
+		fclose(fh);
+		return 1;
+	}
+	
+	end_info = png_create_info_struct(png_ptr);
+	if ( !end_info ) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
+		printf("Couldn't create PNG end info structure.\n");
+		fclose(fh);
+		return 1;
+	}
+	
+	if ( setjmp(png_jmpbuf(png_ptr)) ) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		fprintf(stderr, "PNG read failed.\n");
+		return 1;
+	}
+	
+	png_init_io(png_ptr, fh);
+	png_set_sig_bytes(png_ptr, 8);
+	
+	/* Read! */
+	png_read_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
+	
+	width = png_get_image_width(png_ptr, info_ptr);
+	height = png_get_image_height(png_ptr, info_ptr);
+	bit_depth = png_get_bit_depth(png_ptr, info_ptr);
+	channels = png_get_channels(png_ptr, info_ptr);
+	if ( bit_depth != 8 ) {
+		fprintf(stderr, "Texture image '%s' doesn't have 8 bits per channel per pixel.\n", filename);
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		return 1;
+	}
+	if ( channels != 4 ) {
+		fprintf(stderr, "Texture image '%s' doesn't have 4 channels.\n", filename);
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		return 1;
+	}
+	
+	/* Get image data */
+	row_pointers = png_get_rows(png_ptr, info_ptr);
+	
+	texels = malloc(4*width*height);
+	for ( y=0; y<height; y++ ) {
+		for ( x=0; x<width; x++ ) {
+		
+			unsigned int r, g, b, a;
+
+			r = row_pointers[y][(channels*x)+0];
+			g = row_pointers[y][(channels*x)+1];
+			b = row_pointers[y][(channels*x)+2];
+			a = row_pointers[y][(channels*x)+3];
+			
+			texels[4*(x + width*(height-1-y)) + 0] = r;
+			texels[4*(x + width*(height-1-y)) + 1] = g;
+			texels[4*(x + width*(height-1-y)) + 2] = b;
+			texels[4*(x + width*(height-1-y)) + 3] = a;
+			
+		}
+	}
+	
+	png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+	fclose(fh);
+	
+	fh = fopen(outfilename, "wb");
+	if (!fh) {
+		fprintf(stderr, "Couldn't open output file.\n");
+		return 1;
+	}
+	png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if ( !png_ptr ) {
+		fprintf(stderr, "Couldn't create PNG write structure.\n");
+		fclose(fh);
+		return 1;
+	}	
+	info_ptr = png_create_info_struct(png_ptr);
+	if ( !info_ptr ) {
+		png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
+		fprintf(stderr, "Couldn't create PNG info structure.\n");
+		fclose(fh);
+		return 1;
+	}	
+	if ( setjmp(png_jmpbuf(png_ptr)) ) {
+		png_destroy_write_struct(&png_ptr, &info_ptr);
+		fclose(fh);
+		fprintf(stderr, "PNG write failed.\n");
+		return 1;
+	}	
+	png_init_io(png_ptr, fh);
+	
+	png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGBA, PNG_INTERLACE_NONE,
+		PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+	
+	/* Write the image data */
+	row_pointers = malloc(height*sizeof(png_bytep *));
+
+	for ( y=0; y<height; y++ ) {
+		row_pointers[y] = malloc(width*4);
+		for ( x=0; x<width; x++ ) {
+		
+			row_pointers[y][4*x+0] = texels[4*(x + width*(height-1-y)) + 0];
+			row_pointers[y][4*x+1] = texels[4*(x + width*(height-1-y)) + 1];
+			row_pointers[y][4*x+2] = texels[4*(x + width*(height-1-y)) + 2];
+			row_pointers[y][4*x+3] = texels[4*(x + width*(height-1-y)) + 3];
+			
+		}
+	}
+
+	png_set_rows(png_ptr, info_ptr, row_pointers);
+	png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
+	
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+	for ( y=0; y<height; y++ ) {
+		free(row_pointers[y]);
+	}
+	free(row_pointers);
+	fclose(fh);
+	
+	free(texels);
+	
+	return 0;
+	
+}
+