Initial import

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@1 84d2e878-0bd5-11dd-ad15-13eda11d74c5

1 files changed, 180 insertions, 0 deletions

diff --git a/src/texture.c b/src/texture.c
new file mode 100644
index 0000000..b2aba03
--- /dev/null
+++ b/src/texture.c
@@ -0,0 +1,180 @@
+/*
+ * texture.c
+ *
+ * Handle textures
+ *
+ * (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 <gl.h>
+#include <glu.h>
+
+#include "render.h"
+
+void texture_load(RenderContext *ctx, char *name) {
+
+	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;
+	char tmp[64];
+	uint8_t *texels;
+	
+	/* Open file */
+	snprintf(tmp, 63, "%s/textures/%s.png", DATADIR, name);
+	fh = fopen(tmp, "rb");
+	if ( !fh ) {
+		fprintf(stderr, "Couldn't open texture file '%s'\n", tmp);
+		return ;
+	}
+
+	/* 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", tmp);
+		free(header);
+		fclose(fh);
+		return;
+	}
+	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 ;
+	}
+
+	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;
+	}
+
+	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;
+	}
+	
+	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;
+	}
+
+	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' isn't 8 bits per channel per pixel.\n", tmp);
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		return;
+	}
+	if ( channels != 4 ) {
+		fprintf(stderr, "Texture image '%s' doesn't have 4 channels.\n", tmp);
+		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+		fclose(fh);
+		return;
+	}
+	
+	/* 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;
+			
+		}
+	}
+	
+	glGenTextures(1, &(ctx->textures[ctx->num_textures].texname));
+	glBindTexture(GL_TEXTURE_2D, ctx->textures[ctx->num_textures].texname);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+	glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+	//glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, texels);
+	gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGBA8, width, height, GL_RGBA, GL_UNSIGNED_BYTE, texels);
+	free(texels);
+	ctx->textures[ctx->num_textures].name = name;
+	ctx->num_textures++;
+	
+	png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
+	fclose(fh);
+
+}
+
+Texture *texture_lookup(RenderContext *ctx, const char *name) {
+	
+	int i, found;
+	
+	found = 0;
+	for ( i=0; i<ctx->num_textures; i++ ) {
+		if ( strcmp(ctx->textures[i].name, name) == 0 ) {
+			found = 1;
+			break;
+		}
+	}
+	
+	if ( found == 0 ) {
+		return NULL;
+	}
+	
+	return &(ctx->textures[i]);
+	
+}
+
+void texture_free_all(RenderContext *ctx) {
+	
+	int i;
+	
+	for ( i=0; i<ctx->num_textures; i++ ) {
+		glDeleteTextures(1, &(ctx->textures[ctx->num_textures].texname));
+	}
+	
+}
+