shithub: tinygl

ref: 18949a3f82797cdde959037b56781e1437b56176
dir: /src/select.c/

#include "zgl.h"

int glRenderMode(GLint mode) {
	GLContext* c = gl_get_context();
	GLint result = 0;

	switch (c->render_mode) {
	case GL_RENDER:
		break;
	case GL_SELECT:
		if (c->select_overflow) {
			result = -c->select_hits;
		} else {
			result = c->select_hits;
		}
		c->select_overflow = 0;
		c->select_ptr = c->select_buffer;
		c->name_stack_size = 0;
		break;
	default:
		assert(0);
	}
	switch (mode) {
	case GL_RENDER:
		c->render_mode = GL_RENDER;
		break;
	case GL_SELECT:
		c->render_mode = GL_SELECT;
		assert(c->select_buffer != NULL);
		c->select_ptr = c->select_buffer;
		c->select_hits = 0;
		c->select_overflow = 0;
		c->select_hit = NULL;
		break;
	default:
		assert(0);
	}
	return result;
}

void glSelectBuffer(GLint size, GLuint* buf) {
	GLContext* c = gl_get_context();

	assert(c->render_mode != GL_SELECT);

	c->select_buffer = buf;
	c->select_size = size;
}

void glopInitNames(GLContext* c, GLParam* p) {
	if (c->render_mode == GL_SELECT) {
		c->name_stack_size = 0;
		c->select_hit = NULL;
	}
}

void glopPushName(GLContext* c, GLParam* p) {
	if (c->render_mode == GL_SELECT) {
		assert(c->name_stack_size < MAX_NAME_STACK_DEPTH);
		c->name_stack[c->name_stack_size++] = p[1].i;
		c->select_hit = NULL;
	}
}

void glopPopName(GLContext* c, GLParam* p) {
	if (c->render_mode == GL_SELECT) {
		assert(c->name_stack_size > 0);
		c->name_stack_size--;
		c->select_hit = NULL;
	}
}

void glopLoadName(GLContext* c, GLParam* p) {
	if (c->render_mode == GL_SELECT) {
		assert(c->name_stack_size > 0);
		c->name_stack[c->name_stack_size - 1] = p[1].i;
		c->select_hit = NULL;
	}
}

void gl_add_select(GLContext* c, GLuint zmin, GLuint zmax) {
	GLuint* ptr;
	GLint n, i;

	if (!c->select_overflow) {
		if (c->select_hit == NULL) {
			n = c->name_stack_size;
			if ((c->select_ptr - c->select_buffer + 3 + n) > c->select_size) {
				c->select_overflow = 1;
			} else {
				ptr = c->select_ptr;
				c->select_hit = ptr;
				*ptr++ = c->name_stack_size;
				*ptr++ = zmin;
				*ptr++ = zmax;
				for (i = 0; i < n; i++)
					*ptr++ = c->name_stack[i];
				c->select_ptr = ptr;
				c->select_hits++;
			}
		} else {
			if (zmin < c->select_hit[1])
				c->select_hit[1] = zmin;
			if (zmax > c->select_hit[2])
				c->select_hit[2] = zmax;
		}
	}
}