shithub: tinygl

ref: 6a85da7f3569faa9c0048c2d44b03172f49b020b
dir: /src/texture.c/

/*
 * Texture Manager
 */

#include "zgl.h"

static GLTexture* find_texture(GLContext* c, GLint h) {
	GLTexture* t;

	t = c->shared_state.texture_hash_table[h % TEXTURE_HASH_TABLE_SIZE];
	while (t != NULL) {
		if (t->handle == h)
			return t;
		t = t->next;
	}
	return NULL;
}

void* glGetTexturePixmap(GLint text, GLint level, GLint* xsize, GLint* ysize) {
	GLTexture* tex;
	GLContext* c = gl_get_context();
	assert(text >= 0 && level < MAX_TEXTURE_LEVELS);
	tex = find_texture(c, text);
	if (!tex)
		return NULL;
	*xsize = tex->images[level].xsize;
	*ysize = tex->images[level].ysize;
	return tex->images[level].pixmap;
}

static void free_texture(GLContext* c, GLint h) {
	GLTexture *t, **ht;
	GLImage* im;
	GLint i;

	t = find_texture(c, h);
	if (t->prev == NULL) {
		ht = &c->shared_state.texture_hash_table[t->handle % TEXTURE_HASH_TABLE_SIZE];
		*ht = t->next;
	} else {
		t->prev->next = t->next;
	}
	if (t->next != NULL)
		t->next->prev = t->prev;

	for (i = 0; i < MAX_TEXTURE_LEVELS; i++) {
		im = &t->images[i];
		if (im->pixmap != NULL)
			gl_free(im->pixmap);
	}

	gl_free(t);
}

GLTexture* alloc_texture(GLContext* c, GLint h) {
	GLTexture *t, **ht;

	t = gl_zalloc(sizeof(GLTexture));

	ht = &c->shared_state.texture_hash_table[h % TEXTURE_HASH_TABLE_SIZE];

	t->next = *ht;
	t->prev = NULL;
	if (t->next != NULL)
		t->next->prev = t;
	*ht = t;

	t->handle = h;

	return t;
}

void glInitTextures(GLContext* c) {
	/* textures */

	c->texture_2d_enabled = 0;
	c->current_texture = find_texture(c, 0);
}

void glGenTextures(GLint n, GLuint* textures) {
	GLContext* c = gl_get_context();
	GLint max, i;
	GLTexture* t;

	max = 0;
	for (i = 0; i < TEXTURE_HASH_TABLE_SIZE; i++) {
		t = c->shared_state.texture_hash_table[i];
		while (t != NULL) {
			if (t->handle > max)
				max = t->handle;
			t = t->next;
		}
	}
	for (i = 0; i < n; i++) {
		textures[i] = max + i + 1;
	}
}

void glDeleteTextures(GLint n, const GLuint* textures) {
	GLContext* c = gl_get_context();
	GLint i;
	GLTexture* t;

	for (i = 0; i < n; i++) {
		t = find_texture(c, textures[i]);
		if (t != NULL && t != 0) {
			if (t == c->current_texture) {
				glBindTexture(GL_TEXTURE_2D, 0);
			}
			free_texture(c, textures[i]);
		}
	}
}

void glopBindTexture(GLContext* c, GLParam* p) {
	GLint target = p[1].i;
	GLint texture = p[2].i;
	GLTexture* t;

	assert(target == GL_TEXTURE_2D && texture >= 0);

	t = find_texture(c, texture);
	if (t == NULL) {
		t = alloc_texture(c, texture);
	}
	c->current_texture = t;
}

void glopTexImage2D(GLContext* c, GLParam* p) {
	GLint target = p[1].i;
	GLint level = p[2].i;
	GLint components = p[3].i;
	GLint width = p[4].i;
	GLint height = p[5].i;
	GLint border = p[6].i;
	GLint format = p[7].i;
	GLint type = p[8].i;
	void* pixels = p[9].p;
	GLImage* im;
	GLubyte* pixels1;
	GLint do_free;

	if (!(target == GL_TEXTURE_2D && level == 0 && components == 3 && border == 0 && format == GL_RGB && type == GL_UNSIGNED_BYTE)) {
		gl_fatal_error("glTexImage2D: combination of parameters not handled!!");
	}

	do_free = 0;
	if (width != 256 || height != 256) {
		pixels1 = gl_malloc(256 * 256 * 3);
		/* no GLinterpolation is done here to respect the original image aliasing ! */
		gl_resizeImageNoInterpolate(pixels1, 256, 256, pixels, width, height);
		do_free = 1;
		width = 256;
		height = 256;
	} else {
		pixels1 = pixels;
	}

	im = &c->current_texture->images[level];
	im->xsize = width;
	im->ysize = height;
	if (im->pixmap != NULL)
		gl_free(im->pixmap);
#if TGL_FEATURE_RENDER_BITS == 24
	im->pixmap = gl_malloc(width * height * 3);
	if (im->pixmap) {
		memcpy(im->pixmap, pixels1, width * height * 3);
	}
#elif TGL_FEATURE_RENDER_BITS == 32
	im->pixmap = gl_malloc(width * height * 4);
	if (im->pixmap) {
		gl_convertRGB_to_8A8R8G8B(im->pixmap, pixels1, width, height);
	}
#elif TGL_FEATURE_RENDER_BITS == 16
	im->pixmap = gl_malloc(width * height * 2);
	if (im->pixmap) {
		gl_convertRGB_to_5R6G5B(im->pixmap, pixels1, width, height);
	}
#else
#error TODO
#endif
	if (do_free)
		gl_free(pixels1);
}

/* TODO: not all tests are done */
void glopTexEnv(GLContext* c, GLParam* p) {
	GLint target = p[1].i;
	GLint pname = p[2].i;
	GLint param = p[3].i;

	if (target != GL_TEXTURE_ENV) {
	error:
		gl_fatal_error("glTexParameter: unsupported option");
	}

	if (pname != GL_TEXTURE_ENV_MODE)
		goto error;

	if (param != GL_DECAL)
		goto error;
}

/* TODO: not all tests are done */
void glopTexParameter(GLContext* c, GLParam* p) {
	GLint target = p[1].i;
	GLint pname = p[2].i;
	GLint param = p[3].i;

	if (target != GL_TEXTURE_2D) {
	error:
		gl_fatal_error("glTexParameter: unsupported option");
	}

	switch (pname) {
	case GL_TEXTURE_WRAP_S:
	case GL_TEXTURE_WRAP_T:
		if (param != GL_REPEAT)
			goto error;
		break;
	}
}

void glopPixelStore(GLContext* c, GLParam* p) {
	GLint pname = p[1].i;
	GLint param = p[2].i;

	if (pname != GL_UNPACK_ALIGNMENT || param != 1) {
		gl_fatal_error("glPixelStore: unsupported option");
	}
}